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- T\bTH\bHE\bE I\bIN\bNT\bTE\bER\bRC\bCA\bAL\bL P\bPR\bRO\bOG\bGR\bRA\bAM\bMM\bMI\bIN\bNG\bG L\bLA\bAN\bNG\bGU\bUA\bAG\bGE\bE
- R\bRE\bEV\bVI\bIS\bSE\bED\bD R\bRE\bEF\bFE\bER\bRE\bEN\bNC\bCE\bE M\bMA\bAN\bNU\bUA\bAL\bL
-
- _\bD_\bo_\bn_\ba_\bl_\bd _\bR_\b. _\bW_\bo_\bo_\bd_\bs
- _\ba_\bn_\bd
- _\bJ_\ba_\bm_\be_\bs _\bM_\b. _\bL_\by_\bo_\bn
-
- _\bC_\b-_\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL _\br_\be_\bv_\bi_\bs_\bi_\bo_\bn_\bs_\b:
- _\bL_\bo_\bu_\bi_\bs _\bH_\bo_\bw_\be_\bl_\bl
- _\ba_\bn_\bd
- _\bE_\br_\bi_\bc _\bS_\b. _\bR_\ba_\by_\bm_\bo_\bn_\bd
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- _\b1_\b. _\bI_\bN_\bT_\bR_\bO_\bD_\bU_\bC_\bT_\bI_\bO_\bN
-
-
- "But I don't want to go among mad people," Alice remarked.
-
- "Oh, you ca'n't help that," said the Cat: "We're all mad
- here. I'm mad. You're mad."
-
- "How do you know I'm mad?" said Alice.
-
- "You must be," said the Cat, "or you wouldn't have come
- here."
-
-
- The names you are about to ignore are true. However, the
- story has been changed significantly. Any resemblance of the
- programming language portrayed here to other programming
- languages, living or dead, is purely coincidental.
-
- _\b1_\b._\b1 _\bO_\br_\bi_\bg_\bi_\bn _\ba_\bn_\bd _\bP_\bu_\br_\bp_\bo_\bs_\be
-
- The INTERCAL programming language was designed the morning
- of May 26, 1972 by Donald R. Woods and James M. Lyon, at
- Princeton University. Exactly when in the morning will
- become apparent in the course of this manual.
-
- Eighteen years later (give or take a few months) Eric S.
- Raymond perpetrated a UNIX-hosted INTERCAL compiler as a
- weekend hack. The C-INTERCAL implementation has since been
- maintained and extended by an international community of
- technomasochists, including Louis Howell, Steve Swales,
- Michael Ernst, and Brian Raiter.
-
- (There was evidently an Atari implementation sometime
- between these two; notes on it got appended to the
- INTERCAL-72 manual. The culprits have sensibly declined to
- identify themselves.)
-
- INTERCAL was inspired by one ambition: to have a compiler
- language which has nothing at all in common with any other
- major language. By 'major' was meant anything with which the
- authors were at all familiar, e.g., FORTRAN, BASIC, COBOL,
- ALGOL, SNOBOL, SPITBOL, FOCAL, SOLVE, TEACH, APL, LISP, and
- PL/I. For the most part, INTERCAL has remained true to this
- goal, sharing only the basic elements such as variables,
- arrays, and the ability to do I/O, and eschewing all
- conventional operations other than the assignment statement
- (FORTRAN "=").
-
- _\b1_\b._\b2 _\bA_\bc_\br_\bo_\bn_\by_\bm
-
- The full name of the compiler is "Compiler Language With No
- Pronounceable Acronym", which is, for obvious reasons,
- abbreviated "INTERCAL".
-
-
-
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-
-
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- - 3 -
-
-
-
- _\b1_\b._\b3 _\bA_\bc_\bk_\bn_\bo_\bw_\bl_\be_\bd_\bg_\bm_\be_\bn_\bt_\bs
-
- The authors are deeply indebted to Eric M. Van and Daniel J.
- Warmenhoven, without whose unwitting assistance this manual
- would still have been possible.
-
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- _\b2_\b. _\bF_\bU_\bN_\bD_\bA_\bM_\bE_\bN_\bT_\bA_\bL _\bC_\bO_\bN_\bC_\bE_\bP_\bT_\bS
-
-
- "There's nothing like eating hay when you're faint," the
- White King remarked to Alice, as he munched away.
-
- "I should think throwing cold water over you would be
- better," Alice suggested: "-- or some sal-volatile."
-
- "I didn't say there was nothing _\bb_\be_\bt_\bt_\be_\br," the King replied.
- "I said there was nothing _\bl_\bi_\bk_\be it." Which Alice did not
- venture to deny.
-
-
- In this section an attempt is made to describe how and why
- INTERCAL may be used; i.e., what it is like and what it is
- good for.
-
- _\b2_\b._\b1 _\bS_\ba_\bm_\bp_\bl_\be _\bP_\br_\bo_\bg_\br_\ba_\bm
-
- Shown below is a relatively simple INTERCAL program which
- will read in 32-bit unsigned integers, treat them as signed,
- 2's-complement numbers, and print out their absolute values.
- The program exits if the absolute value is zero. Note in
- particular the inversion routine (statements 6 through 14),
- which could be greatly simplified if the subroutine library
- (see section ) were used.
-
- A more detailed analysis of a program is made in section
- of this manual.
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- - 5 -
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- DO (5) NEXT
- (5) DO FORGET #1
- PLEASE WRITE IN :1
- DO .1 <- 'V\b-":1~'#32768c\b/#0'"c\b/#1'~#3
- DO (1) NEXT
- DO :1 <- "'V\b-":1~'#65535c\b/#0'"c\b/#65535'
- ~'#0c\b/#65535'"c\b/"'V\b-":1~'#0c\b/#65535'"
- c\b/#65535'~'#0c\b/#65535'"
- DO :2 <- #1
- PLEASE DO (4) NEXT
- (4) DO FORGET #1
- DO .1 <- "V\b-':1~:2'c\b/#1"~#3
- DO :1 <- "'V\b-":1~'#65535c\b/#0'"c\b/":2~'#65535
- c\b/#0'"'~'#0c\b/#65535'"c\b/"'V\b-":1~'#0
- c\b/#65535'"c\b/":2~'#0c\b/#65535'"'~'#0c\b/#65535'"
- DO (1) NEXT
- DO :2 <- ":2~'#0c\b/#65535'"
- c\b/"'":2~'#65535c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- DO (4) NEXT
- (2) DO RESUME .1
- (1) PLEASE DO (2) NEXT
- PLEASE FORGET #1
- DO READ OUT :1
- PLEASE DO .1 <- 'V\b-"':1~:1'~#1"c\b/#1'~#3
- DO (3) NEXT
- PLEASE DO (5) NEXT
- (3) DO (2) NEXT
- PLEASE GIVE UP
-
-
- _\b2_\b._\b2 _\bU_\bs_\be_\bs _\bf_\bo_\br _\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL
-
- INTERCAL's main advantage over other programming languages
- is its strict simplicity. It has few capabilities, and thus
- there are few restrictions to be kept in mind. Since it is
- an exceedingly easy language to learn, one might expect it
- would be a good language for initiating novice programmers.
- Perhaps surprising, then, is the fact that it would be more
- likely to initiate a novice into a search for another line
- of work. As it turns out, INTERCAL is more useful (which
- isn't saying much) as a challenge to professional
- programmers. Those who doubt this need only refer back to
- the sample program in section . This 23-statement program
- took somewhere from 15 to 30 minutes to write, whereas the
- same objectives can be achieved by single-statement programs
- in either SNOBOL;
-
- PLEASE INPUT POS(0) ('-' ! '')
- + (SPAN('0123456789') $ OUTPUT)
- + *NE(OUTPUT) :S(PLEASE)F(END)
-
- or APL;
-
- [1] ->0!=[]<-|[]
-
-
-
-
-
-
-
-
- - 6 -
-
-
-
- Admittedly, neither of these is likely to appear more
- intelligible to anyone unfamiliar with the languages
- involved, but they took roughly 60 seconds and 15 seconds,
- respectively, to write. Such is the overwhelming power of
- INTERCAL!
-
- The other major importance of INTERCAL lies in its seemingly
- inexhaustible capacity for amazing one's fellow programmers,
- confounding programming shop managers, winning friends, and
- influencing people. It is a well-known and oft-demonstrated
- fact that a person whose work is incomprehensible is held in
- high esteem. For example, if one were to state that the
- simplest way to store a value of 65536 in a 32-bit INTERCAL
- variable is:
-
- DO :1 <- #0c\b/#256
-
- any sensible programmer would say that that was absurd.
- Since this is indeed the simplest method, the programmer
- would be made to look foolish in front of his boss, who
- would of course happened to turn up, as bosses are wont to
- do. The effect would be no less devastating for the
- programmer having been correct.
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- _\b3_\b. _\bD_\bE_\bS_\bC_\bR_\bI_\bP_\bT_\bI_\bO_\bN
-
-
- "I quite agree with you," said the Duchess; "and the moral
- of that is -- 'Be what you would seem to be' -- or, if you'd
- like it put more simply -- 'Never imagine yourself not to be
- otherwise than what it might appear to others that what you
- were or might have been was not otherwise than what you had
- been would have appeared to them to be otherwise."
- "I think I should understand that better," Alice said very
- politely, "if I had it written down: but I ca'n't quite
- follow it as you say it."
-
- "That's nothing to what I could say if I chose," the Duchess
- replied, in a pleased tone.
-
-
- The examples of INTERCAL programming which have appeared in
- the preceding sections of this manual have probably seemed
- highly esoteric to the reader unfamiliar with the language.
- With the aim of making them more so, we present here a
- description of INTERCAL.
-
- _\b3_\b._\b1 _\bV_\ba_\br_\bi_\ba_\bb_\bl_\be_\bs
-
- INTERCAL allows only 2 different types of variables, the
- 1\b16\b6-\b-b\bbi\bit\bt i\bin\bnt\bte\beg\bge\ber\br and the 3\b32\b2-\b-b\bbi\bit\bt i\bin\bnt\bte\beg\bge\ber\br.\b. These are
- represented by a spot (.) or two-spot (:), respectively,
- followed by any number between 1 and 65535, inclusive.
- These variables may contain only non-negative numbers; thus
- they have the respective ranges of values: 0 to 65535 and 0
- to 4294967295. Note: .123 and :123 are two distinct
- variables. On the other hand, .1 and .0001 are identical.
- Furthermore, the latter may _\bn_\bo_\bt be written as 1E-3.
-
- _\b3_\b._\b2 _\bC_\bo_\bn_\bs_\bt_\ba_\bn_\bt_\bs
-
- C\bCo\bon\bns\bst\bta\ban\bnt\bts\bs are 16-bit values only and may range from 0 to
- 65535. They are prefixed by a mesh (#). Caution! Under no
- circumstances confuse the mesh with the interleave operator,
- except under confusing circumstances!
-
- _\b3_\b._\b3 _\bA_\br_\br_\ba_\by_\bs
-
- A\bAr\brr\bra\bay\bys\bs are represented by a tail (,) for 16-bit values, or a
- hybrid (;) for 32-bit values, followed by a number between 1
- and 65535, inclusive. The number is suffixed by the word
- SUB, followed by the subscripts, separated optionally by
- spaces. Subscripts may be any expressions, including those
- involving subscripted variables. This occasionally leads to
- ambiguous constructions, which are resolved as discussed in
- section . Definition of array dimensions will be discussed
- later in greater detail, since discussing it in less detail
- would be difficult. As before, ,123 and ;123 are distinct.
-
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- - 8 -
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- In summary, .123, :123, #123, ,123, and ;123 are all
- distinct.
-
- _\b3_\b._\b4 _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- INTERCAL recognizes 5 operators -- 2 binary and 3 unary 1.
- Please be kind to our operators: they may not be very
- intelligent, but they're all we've got. In a sense, all 5
- operators are binary, as they are all bit-oriented, but it
- is not our purpose here to quibble about bits of trivia.
-
- _\b3_\b._\b4_\b._\b1 _\bB_\bi_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- The binary operators are i\bin\bnt\bte\ber\brl\ble\bea\bav\bve\be (also called m\bmi\bin\bng\bgl\ble\be) and
- s\bse\bel\ble\bec\bct\bt, which are represented by a change (c\b/) and a sqiggle
- [sic] (~), respectively. (In C-INTERCAL's ASCII
- environment, EBCDIC c\b/ is replaced by a big money ($), but c\b/
- can be used if encoded in Latin-1 as \0xA2 or UTF-8 as
- 0xC2A2.)
-
- The interleave operator takes two 16-bit values and produces
- a 32-bit result by alternating the bits of the operands.
- Thus, #65535c\b/#0 has the 32-bit binary form 101010....10 or
- 2863311530 decimal, while #0c\b/#65535 = 0101....01 binary =
- 1431655765 decimal, and #255c\b/#255 is equivalent to #65535.
-
- The select operator takes from the first operand whichever
- bits correspond to 1's in the second operand, and packs
- these bits to the right in the result. Both operands are
- automatically padded on the left with zeros to 32 bits
- before the selection takes place, so the variable types are
- unrestricted. If more than 16 bits are selected, the result
- is a 32-bit value, otherwise it is a 16-bit value. For
- example, #179~#201 (binary value 10110011~11001001) selects
- from the first argument the 8th, 7th, 4th, and 1st from last
- bits, namely, 1001, which = 9. But #201~#179 selects from
- binary 11001001 the 8th, 6th, 5th, 2nd, and 1st from last
- bits, giving 10001 = 17. #179~#179 has the value 31, while
- #201~#201 has the value 15.
-
- Perhaps a simpler way of understanding the operation of the
- select operator would be to examine the logic diagram in
- Figure 1, which performs the select operation upon two 8-bit
- values, A and B. The gates used are Warmenhovian logic
- gates, which means the outputs have four possible values:
- low, high, undefined (value of an uninitialized flip-flop),
- and oscillating (output of a NOR gate with one input low and
- the other input connected to the output). These values are
- represented symbolically by '0', '1', '?', and 'O\b|'. Note in
- particular that, while NOT-0 is 1 and NOT-1 is 0 as in two-
-
- ____________________
-
- 1. Other operators are also available with C-INTERCAL's non-
- standard dialects; see section .
-
-
-
-
-
-
-
- - 9 -
-
-
-
- valued logic, NOT-? is ? and NOT-O\b| is O\b|. The functions of
- the various gates are listed in Table 1.
-
- [Warning: The following picture will be garbled or missing.
- Get a better output device.]
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- - 10 -
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-
- --+-+---- --+---- +--+---- --+---- +--+----
- A\b1 | | 1 +-+--+-+ 2 +-++-+ 3 ++-+-+ 3 ++|--+ 1 +--
- B --+++ | |--+-+ | || | ||||++ |||| | | TO
- 1 +++------++-+-+------+|-+--- +++++-----++|-+--- ---\bNEW
- +-------++-+---------+-------+++++-----+ | YORK
- +-+------++-+-+-----+ | +---- ||| +-----+ | +---- TO
- A\b2 --+-+ | || +-+ || --+ |+++-+ |+-+-+ | ---\bNEW
- --+-+ 1 +-++-+-+ 2 +++--+ 7 +-++-+ 3 +--+-+ 2 +-- YO\bTR\bOK
- B\b2 |-+--- |||+-+--- || -+--- |+-+------++-+------- ---\bNEW
- +--------+++-+------++---------+--------+|+--------- YORK
- +-+------+++-++-----++--+-----+| ++-----++--+-----+ TO
- A --+-+ | +++-++ |++--+ |++-++ ||+--+ || B ---\bNEW
- 3 | 1 +-+++-+| 2 +-++-+ 3 +-++++ 3 ++++-+ 3 ++- YORK
- B\b3 --+-+--- ||||+++--- |||-+--- ++|++--- ||+++--- | TO
- +-------++++++------+++-------++++------++++------+-U ---\bNEW
- +-+-----+++-+++-----+++-+-----+++|| ++++| | YORK
- A --+-+----|||| ||+----||++-+----||++++----|+++++----|| S TO
- 4 | 1 +++++|++ 2 ++++-+ 7 ++++++ 3 ++++-+ 4 ++- ---\bNEW
- B --+-+--- ||||+-+--- ||+-+--- |||++--- ++--++--- | YO\bTR\bOK
- 4 | |||+++ ++--+ +---++++++++++|+-+------+ ---\bNEW
- +-------+++-++-------++++-+--+||+++++++-++++--+ YORK
- --+-+-----+++-+++-----+++++-+--+++-++++++ +++++-+-- L TO
- A\b5 | 1 ++++++++ 2 ++++++ 3 +++ ++ 3 +-++++ 5 +-- ---\bNEW
- B --+-+ |||+++++ | ||| ||| || |++++| | YORK
- 5 |-+--- |||||++-------|++----+|+--+-----+++++-------I TO
- +-------+++++--------++------++++ +--- |+++ ---\bNEW
- +-+-----+++++-+-----+|| +----++++++-----+|||+---- N YORK
- A\b6 --+-+ |||-++++ |+++-+ |+++++ | ++++ | TO
- --+-+ 1 +++-++++ 2 ++++-+ 3 +-++++ 4 ++++++ 4 +-- ---\bNEW
- B\b6 |-+--- +++++++--- +++-+-----+||++-----+++++-------E YORK
- +--------++++--------++------+||| ++-+ ---TO
- +-+------++++-+-----+|| +----++++++---- || +---- NEW
- A --+-+ | -+++-+ |+++-+ |+++++ ||+--+ | YO\bTR\bOK
- 7 | 1 +--+|+-+ 2 +-++-+ 3 ++|+++ 4 ++-+-+ 5 +-- ---\bNEW
- B\b7 --+-+--- ||++-+--- ||++--- || ++--- --+++--- YORK
- +----+---++++--------+++------++ +------+-++------+- TO
- +-+--+---++++-+-------+|| | || | || | ---\bNEW
- A --+-+----| |+++-+----|+-+++----|+--++----||+--+----|| YORK
- 8 | 1 +-+ |+-+ 2 ++ +++ 4 ++ +++ 3 ++++-+ 5 ++-8 TO
- B --+-+--- +--+--- | ++--- | |++--- | |-+--- | ---\bNEW
- 8 +----------------+ ++-+ +-++---+ ++-+------+| YORK
- +--+++--------+|| +-++++------++- TO
- +---- +-+--+-----+++-+---- ++++----+|++-+----++- ---\bNEW
- | 6 +-+ +--+ 2 ++-+-+ 7 +-++-+ 3 +++|++ 4 ++- YO\bTR\bOK
- | | -+--+ |+---+ | | | || ||| || --\bP-\bHILA-
- -+--- | -+--- -+--- |-+--- +-+++--- | DELPHIA
- +---------------------+---------+-------+-
- +---- |+--+---------+------++-+-----+ +----
- | | ++--+ | +-+ | |--+ ||+--+ |
- | 6 +--++--+ 1 +-++-+ 1 +-+--+ 1 +++--+ 1 ++
- -+--- -+--- --++-+--- | -+--- | -+-----+-
- --- ---
- FIGURE 1. CIRCUITOUS DIAGRAM
-
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- - 11 -
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- __________________________________________________________
- |\ \
- | \ 1. Logic gate. Inputs A, B. Output O = AB. \
- | \ \
- | \ \ 2. Logic gate. Inputs A, B, C. Output O = A+BC. \
- | |\ \ \
- | | \ \ 3. Logic gate. Inputs A, B. Output O = A+AB. \
- | | \ \ \
- | | |\ \ 4. Logic gate. Inputs A, B. Output O = AB O\b+ -(A+-B) \
- | | | \ \ \
- | | | \ \ 5. Logic gate. Inputs A, B. Output O = AO\b+A + AA \
- | | | \ \ \
- | | | \ \ 6. Uninitialized flip-flop. Inputs none. Output O = ? \
- | | | \ \ \
- | | | \ \ 7. Flip-flop-flap. Inputs A, B, C. Output O = 1 if \
- | | | \ \ A=0 or B+C=0 and A=1. O = 0 if AC=1, B=0. O = O\b| if \
- | | | \ \ AB=1, C=0. O = ? if ABC=1. O as yet undetermined \
- | | | \ \ for other Warmenhovian inputs. See Figure 2. \
- | | | \ \ \
- | | | \ \ 8. Bus line. \
- | | | \ \_________________________________________________________\
- | | | \ | |
- | | | | | _____________________________________________________ |
- | | | | | | | | | | | |
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- \|__| | | | \|__| | | |
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- \|__| \|__|
-
- Table 1. Logical (and other) functions.
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- - 12 -
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- [Warning: The following picture will be garbled or missing.
- Get a better output device.]
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-
- -------------------------+----
- A +---+ |----+------------D
- | | | |
- +----
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-
-
- | | |
- +---+---- |
- B-------------------------+ |----+ |
- +----| | |
- | |
- | |
- | |
- | |
- | | |
- C-------------------------+----| | |
- +----------------+ |--+ | |
- | +---- | | |
- | | | |
- | |
- | |
- | |
- | | | | |
- | | +-+----| |
- | +---+ +- +-------+
- | +-+--
- 1-----+
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- FIGURE 2. FLIP FLAP FLOP
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- - 13 -
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- [Warning: The following picture will be garbled or missing.
- Get a better output device.]
-
- -----
- ----- -----
- -----
- ----- -----
-
- ----- -----
- -----
- ----- -----
- ----- GATE TYPE 9. BLACK BOX
- ----- 9 ----- INPUTS A1-8, B1-8.
- ----- OUTPUT O1-8 = A1-8~B1-8
- ----- -----
- -----
- ----- -----
-
- ----- -----
- -----
- ----- -----
- -----
-
-
-
-
-
-
-
-
-
-
-
- FIGURE 1 (CONTINUED). NEW YORK
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 14 -
-
-
-
- _\b3_\b._\b4_\b._\b1_\b._\b1 _\bR_\be_\bt_\bu_\br_\bn _\bt_\by_\bp_\be _\bo_\bf _\bS_\bE_\bL_\bE_\bC_\bT
-
- INTERCAL-72 defined the return type of a select operation to
- depend on the number of bits selected. The C-INTERCAL
- compiler takes the easier route of defining the return type
- to be that of the right operand, independent of its actual
- value. This form has the advantage that all types can be
- determined at compile time. Putting in run-time type-
- checking would add significant overhead and complication, to
- effect a very minor change in language semantics.
-
- The only time this distinction makes any difference is when
- a unary operator is applied to the select result. This
- happens extremely rarely in practice, the only known
- instance being the 32-bit greater-than test in the standard
- library, where an XOR operator is applied to the result of
- selecting a number against itself. The INTERCAL-72 authors
- first select the result against #65535c\b/#65535 to insure that
- XOR sees a 32-bit value. With the current compiler this
- extra step is unnecessary, but harmless.
-
- The cautious programmer should write code that does not
- depend on the compiler version being used. We therefore
- suggest the following guideline for determining the select
- return type:
-
- A select operation with a 16-bit right operand returns a
- 16-bit value. The return type of a select operation with a
- 32-bit right operand is undefined, but is guaranteed to be
- an acceptable input to a mingle operation so long as 16 or
- fewer bits are actually selected. Correct code should not
- depend on whether the return type is 16 or 32 bits.
-
- _\b3_\b._\b4_\b._\b2 _\bU_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- The unary operators are & (logical A\bAN\bND\bD), V (logical O\bOR\bR), and
- V\b- (logical X\bXO\bOR\bR). This last character is obtained by
- overpunching a worm (-) on a V (V). (In C-INTERCAL, V\b- is
- replaced by what (?). The compiler recognizes V<backspace>-
- as a valid equivalent, in case you are concerned about
- compatibility with the Princeton compiler. In version 0.20
- and later, the Unicode character U+2200 FOR ALL, which looks
- exactly like V<backspace>- or an upside-down `A' is also
- accepted in UTF-8 form.) The operator is inserted between
- the spot, two-spot, mesh, or what-have-you, and the integer,
- thus: .&123, #V\b-123. Multiple unary operators may not be
- concatenated, thus the form #V\b-&123 is invalid. This will be
- covered later when precedence is discussed. These operators
- perform their respective logical operations on all pairs of
- adjacent bits, the result from the first and last bits going
- into the first bit of the result. The effect is that of
- rotating the operand one place to the right and ANDing,
- ORing, or XORing with its initial value. Thus, #&77 (binary
- = 1001101) is binary 0000000000000100 = 4, #V77 is binary
-
-
-
-
-
-
-
-
- - 15 -
-
-
-
- 1000000001101111 = 32879, and #V\b-77 is binary
- 1000000001101011 = 32875.
-
- _\b3_\b._\b4_\b._\b3 _\bP_\br_\be_\bc_\be_\bd_\be_\bn_\bc_\be
-
- Precedence of operators is as follows:
-
-
-
-
-
-
-
-
-
-
- (The remainder of this page intentionally left blank)2
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- ____________________
-
- 2. Keep in mind that the aim in designing INTERCAL was to
- have no precedents.
-
-
-
-
-
-
-
- - 16 -
-
-
-
- This precedence (or lack thereof) may be overruled by
- grouping expressions between pairs of sparks (') or rabbit-
- ears ("). Thus '#165c\b/#203'~#358 (binary value
- '10100101c\b/11001011'~101100110) has the value 15, but
- #165c\b/'#203~#358' has the value 34915, and #165c\b/#203~#358 is
- invalid syntax and is completely valueless (except perhaps
- as an educational tool to the programmer). A unary operator
- is applied to a sparked or rabbit-eared expression by
- inserting the operator immediately following the opening
- spark or ears. Thus, the invalid expression #V\b-&123, which
- was described earlier, could be coded as 'V\b-#&123' or
- 'V\b-"{"'. Note: In the interests of simplifying the
- sometimes overly-complex form of expressions, INTERCAL
- allows a spark-spot combination ('.) to be replaced with a
- wow (!). Thus '.1~.2' is equivalent to !1~.2', and 'V.1c\b/.2'
- is equivalent to "V!1c\b/.2'".
-
- Combining a rabbit-ears with a spot to form a rabbit ("\b.) is
- not permitted, although the programmer is free to use it
- should he find an EBCDIC reader which will properly
- translate a 12-3-7-8 punch.
-
- Sparks and/or rabbit-ears must also be used to distinguish
- among such otherwise ambiguous subscripted and multiply-
- subscripted expressions as:
-
- ,1 SUB #1 ~ #2
- ,1 SUB ,2 SUB #1 #2 #3
- ,1 SUB " ,2 SUB " ,3 SUB #1 " #2 " " #3 "
-
- The third case may be isolated into either of its possible
- interpretations by simply changing some pairs of rabbit-ears
- to sparks, instead of adding more ears (which would only
- confuse the issue further). Ambiguous cases are defined as
- those for which the compiler being used finds a legitimate
- interpretation which is different from that which the user
- had in mind. See also section .
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 17 -
-
-
-
- _\b4_\b. _\bS_\bT_\bA_\bT_\bE_\bM_\bE_\bN_\bT_\bS
-
-
- "There's glory for you!"
-
- "I don't know what you mean by 'glory,'" Alice said.
-
- Humpty Dumpty smiled contemptuously. "Of course you don't --
- till I tell you. I meant 'there's a nice knock-down argument
- for you!'"
- "But 'glory' doesn't mean 'a nice knock-down argument.'"
- Alice objected.
-
- "When _\bI use a word," Humpty Dumpty said, in a rather
- scornful tone, "it means just what I choose it to mean --
- neither more nor less."
-
-
- In this section is described the format of INTERCAL
- statements.
-
- _\b4_\b._\b1 _\bG_\be_\bn_\be_\br_\ba_\bl _\bF_\bo_\br_\bm_\ba_\bt
-
- Statements may be entered in 'free format'. That is, more
- than one statement may occur on a single card, and a
- statement may begin on one card and end on a later one. Note
- that if this is done, all intervening cards and portions
- thereof must be part of the same statement. That this
- restriction is necessary is immediately apparent from the
- following example of what might occur if statements could be
- interlaced.
-
- DO .1 <- ".1c\b/'&:51~"#V\b-1c!12~;&75SUB"V\b-'V.1~
- DO .2 <- '"!1c\b/"&';V\b-79SUB",&7SUB:173"'~!V\b-9c\b/
- .2'c\b/,&1SUB:5~#33578"'"'"~'#65535c\b/"V\b-'V#&85'"'
- #8196'"'~.1"c\b/.2'~'#&5c\b/"'#1279c\b/#4351'~#65535"'
-
- The above statements are obviously meaningless. (For that
- matter, so are the statements
-
- DO .1 <- ".1c\b/"&:51~"#V\b-1c\b/!12~;&75SUB"V\b-'V.1~
- .2'c\b/,&1SUB:5~#333578"'"'"~#65535c\b/"V\b-'V#&85'"'
- DO .2 <- '"!1c\b/"&';V\b-79SUB",&7SUB:173"'~!V\b-9c\b/
- #8196'"'~.1"c\b/.2'~'#&5c\b/"'#1279c\b/#4351'~#65535"'
-
- but this is not of interest here.)
-
- Spaces may be used freely to enhance program legibility (or
- at least reduce program illegibility), with the restriction
- that no word of a statement identifier (see section ) may
- contain any spaces.
-
- _\b4_\b._\b2 _\bL_\ba_\bb_\be_\bl_\bs
-
-
-
-
-
-
-
-
-
- - 18 -
-
-
-
- A statement may begin with a l\blo\bog\bgi\bic\bca\bal\bl l\bli\bin\bne\be l\bla\bab\bbe\bel\bl enclosed in
- wax-wane pairs (()). A statement may not have more than one
- label, although it is possible to omit the label entirely. A
- line label is any integer from 1 to 65535, which must be
- unique within each program. The user is cautioned, however,
- that many line labels between 1000 and 1999 are used in the
- INTERCAL System Library functions.
-
- _\b4_\b._\b3 _\bI_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br_\bs _\ba_\bn_\bd _\bQ_\bu_\ba_\bl_\bi_\bf_\bi_\be_\br_\bs
-
- After the line label (if any), must follow one of the
- following statement identifiers: DO, PLEASE, or PLEASE DO.
- These may be used interchangeably to improve the aesthetics
- of the program. The identifier is then followed by either,
- neither, or both of the following optional parameters
- (qualifiers): (1) either of the character strings NOT or
- N'T, which causes the statement to be automatically
- abstained from (see section ) when execution begins, and (2)
- a number between 0 and 100, preceded by a double-oh-seven
- (%), which causes the statement to have only the specified
- percent chance of being executed each time it is encountered
- in the course of execution.
-
- _\b4_\b._\b4 _\bS_\bt_\ba_\bt_\be_\bm_\be_\bn_\bt_\bs
-
- Following the qualifiers (or, if none are used, the
- identifier) must occur one of the 14 valid operations.
- (Exception: see section .) These are described individually
- in sections
- through .
-
- _\b4_\b._\b4_\b._\b1 _\bC_\ba_\bl_\bc_\bu_\bl_\ba_\bt_\be
-
- The INTERCAL equivalent of the half-mesh (=) in FORTRAN,
- BASIC, PL/I, and others, is represented by an angle (<)
- followed by a worm (-). This combination is read 'gets'.
- 32-bit variables may be assigned 16-bit values, which are
- padded on the left with 16 zero bits. 16-bit variables may
- be assigned 32-bit values only if the value is less than
- 65535. Thus, to invert the least significant bit of the
- first element of 16-bit 2-dimensional array number 1, one
- could write:
-
- ,1SUB#1#1 <- 'V\b-",1SUB#1#1"c\b/#1'~'#0c\b/#65535'
-
- Similarly to SNOBOL and SPITBOL, INTERCAL uses the angle-
- worm to define the dimensions of arrays. An example will
- probably best describe the format. To define 32-bit array
- number 7 as 3-dimensional, the first dimension being seven,
- the second being the current value of 16-bit variable number
- seven, and the third being the current value of the seventh
- element of 16-bit array number seven (which is one-
- dimensional) mingled with the last three bits of 32-bit
- variable number seven, one would write (just before they
-
-
-
-
-
-
-
-
- - 19 -
-
-
-
- came to take him away):
-
- ;7 <- #7 BY .7 BY ",7SUB#7"c\b/':7~#7'
-
- This is, of course, different from the statement:
-
- ;7 <- #7 BY .7 BY ,7SUB"#7c\b/':7~#7'"
-
- INTERCAL also permits the redefining of array dimensioning,
- which is done the same way as is the initial dimensioning.
- All values of items in an array are lost upon
- redimensioning, unless they have been STASHed (see section
- ), in which case restoring them also restores the old
- dimensions.
-
- _\b4_\b._\b4_\b._\b2 _\bN_\bE_\bX_\bT
-
- The NEXT statement is used both for subroutine calls and for
- unconditional transfers. This statement takes the form:
-
- DO (label) NEXT
-
- (or, of course,
-
- PLEASE DO (label) NEXT
-
- etc.), where (label) represents any logical line label which
- appears in the program. The effect of such a statement is to
- transfer control to the statement specified, and to store in
- a push down list (which is initially empty) the location
- from which the transfer takes place. Items may be removed
- from this list and may be discarded or used to return to the
- statement immediately following the NEXT statement. These
- operations are described in sections
- and
- respectively. The programmer is generally advised to
- discard any stack entries which he does not intend to
- utilize, since the stack has a maximum depth of 79 entries.
- A program's attempting to initiate an 80th level of NEXTing
- will result in the fatal error message, "PROGRAM HAS
- DISAPPEARED INTO THE BLACK LAGOON."
-
- _\b4_\b._\b4_\b._\b3 _\bF_\bO_\bR_\bG_\bE_\bT
-
- The statement PLEASE FORGET exp, where exp represents any
- expression (except colloquial and facial expressions),
- causes the expression to be evaluated, and the specified
- number of entries to be removed from the NEXTing stack and
- discarded. An attempt to FORGET more levels of NEXTing than
- are currently stacked will cause the stack to be emptied,
- and no error condition is indicated. This is because the
- condition is not considered to be an error. As described in
- section , it is good programming practice to execute a DO
- FORGET #1 after using a NEXT statement as an unconditional
-
-
-
-
-
-
-
-
- - 20 -
-
-
-
- transfer, so that the stack does not get cluttered up with
- unused entries:
-
- DO (123) NEXT
- .
- .
- (123) DO FORGET #1
-
-
- _\b4_\b._\b4_\b._\b4 _\bR_\bE_\bS_\bU_\bM_\bE
-
- The statement PLEASE RESUME exp has the same effect as
- FORGET, except that program control is returned to the
- statement immediately following the NEXT statement which
- stored in the stack the last entry to be removed. Note that
- a rough equivalent of the FORTRAN computed GO TO and BASIC
- ON exp GO TO is performed by a sequence of the form:
-
- DO (1) NEXT
- .
- .
- (1) DO (2) NEXT
- PLEASE FORGET #1
- .
- .
- (2) DO RESUME .1
-
- Unlike the FORGET statement, an attempt to RESUME more
- levels of NEXTing than has been stacked will cause program
- termination. See also section .
-
- _\b4_\b._\b4_\b._\b5 _\bS_\bT_\bA_\bS_\bH
-
- Since subroutines are not explicitly implemented in
- INTERCAL, the NEXT and RESUME statements must be used to
- execute common routines. However, as these routines might
- use the same variables as the main program, it is necessary
- for them to save the values of any variables whose values
- they alter, and later restore them. This process is
- simplified by the STASH statement, which has the form DO
- STASH list, where list represents a string of one or more
- variable or array names, separated by intersections (+).
- Thus
-
- PLEASE STASH .123+:123+,123
-
- stashes the values of two variables and one entire array.
- The values are left intact, and copies thereof are saved for
- later retrieval by (what else?) the RETRIEVE statement (see
- section ). It is not possible to STASH single array items.
-
- _\b4_\b._\b4_\b._\b6 _\bR_\bE_\bT_\bR_\bI_\bE_\bV_\bE
-
- PLEASE RETRIEVE list restores the previously STASHed values
-
-
-
-
-
-
-
-
- - 21 -
-
-
-
- of the variables and arrays named in the list. If a value
- has been stashed more than once, the most recently STASHed
- values are RETRIEVEd, and a second RETRIEVE will restore the
- second most recent values STASHed. Attempting to RETRIEVE a
- value which has not been STASHed will result in the error
- message, "THROW STICK BEFORE RETRIEVING."
-
- _\b4_\b._\b4_\b._\b7 _\bI_\bG_\bN_\bO_\bR_\bE
-
- The statement DO IGNORE list causes all subsequent
- statements to have no effect upon variables and/or arrays
- named in the list. Thus, for example, after the sequence
-
- DO .1 <- #1
- PLEASE IGNORE .1
- DO .1 <- #0
-
- 16-bit variable number 1 would have the value 1, not 0.
- Inputting (see section ) into an IGNOREd variable also has
- no effect. The condition is annulled via the REMEMBER
- statement (see section ). Note that, when a variable is
- being IGNOREd, its value, though immutable, is still
- available for use in expressions and the like.
-
- Though the INTERCAL-72 manual laid down that the value of an
- IGNOREd variable cannot change, it was unclear about whether
- or not a statement which appears to change an IGNOREd
- variable is executed or not. This may appear to be a "If a
- tree falls in the forest ..." type of question, but if the
- statement in question has other side effects it is not.
-
- Since another mechanism already exists for ABSTAINing from a
- statement, C-INTERCAL's IGNORE only prevents the changing of
- the specific variable in question, not the execution of the
- entire statement. In the present version of the language
- this only makes a difference for the WRITE IN (see ) and
- RETRIEVE (see ) statements. Attempting to WRITE IN to an
- IGNOREd variable will cause a number to be read from the
- input, which will be discarded since it cannot be stored in
- the variable. Using RETRIEVE on an IGNOREd variable will
- pop the variable's stash stack without actually changing its
- value.
-
- _\b4_\b._\b4_\b._\b8 _\bR_\bE_\bM_\bE_\bM_\bB_\bE_\bR
-
- PLEASE REMEMBER list terminates the effect of the IGNORE
- statement for all variables and/or arrays named in the list.
- It does not matter if a variable has been IGNOREd more than
- once, nor is it an error if the variable has not been
- IGNOREd at all.
-
- _\b4_\b._\b4_\b._\b9 _\bA_\bB_\bS_\bT_\bA_\bI_\bN
-
- INTERCAL contains no simple equivalent to an IF statement or
-
-
-
-
-
-
-
-
- - 22 -
-
-
-
- computed GO TO, making it difficult to combine similar
- sections of code into a single routine which occasionally
- skips around certain statements. The IGNORE statement (see
- section ) is helpful in some cases, but a more viable method
- is often required. In keeping with the goal of INTERCAL
- having nothing in common with any other language, this is
- made possible via the ABSTAIN statement.
-
- This statement takes on one of two forms. It may not take on
- both at any one time. DO ABSTAIN FROM (label) causes the
- statement whose logical line label is (label) to be
- abstained from. PLEASE ABSTAIN FROM gerund list causes all
- statements of the specified type(s) to be abstained from, as
- in
-
- PLEASE ABSTAIN FROM STASHING
- PLEASE ABSTAIN FROM IGNORING + FORGETTING
- PLEASE ABSTAIN FROM NEXTING
- or PLEASE ABSTAIN FROM CALCULATING
-
- Statements may also be automatically abstained from at the
- start of execution via the NOT or N'T parameter (see section
- ).
-
- If, in the course of execution, a statement is encountered
- which is being abstained from, it is ignored and control
- passes to the next statement in the program (unless it, too,
- is being abstained from).
-
- The statement DO ABSTAIN FROM ABSTAINING is perfectly valid,
- as is DO ABSTAIN FROM REINSTATING (although this latter is
- not usually recommended). However, the statement DO ABSTAIN
- FROM GIVING UP is not accepted, even though DON'T GIVE UP
- is.
-
- _\b4_\b._\b4_\b._\b1_\b0 _\bR_\bE_\bI_\bN_\bS_\bT_\bA_\bT_\bE
-
- The REINSTATE statement, like the ABSTAIN, takes as an
- argument either a line label or a gerund list. No other form
- of argument is permitted. For example, the following is an
- invalid argument:
-
- Given: x!=0, y!=0, Prove: x+y=0
- Since x!=0, then x+1!=1, x+a!=a, x+y!=y.
- But what is y? y is anything but 0.
- Thus x+y != anything but 0.
- Since x+y cannot equal anything but 0, x+y=0.
- Q.E.D.
-
- REINSTATEment nullifies the effects of an abstention. Either
- form of REINSTATEment can be used to "free" a statement,
- regardless of whether the statement was abstained from by
- gerund list, line label, or NOT. Thus, PLEASE REINSTATE
- REINSTATING is not necessarily an irrelevant statement,
-
-
-
-
-
-
-
-
- - 23 -
-
-
-
- since it might free a DON'T REINSTATE command or a REINSTATE
- the line label of which was abstained from. However, DO
- REINSTATE GIVING UP is invalid, and attempting to REINSTATE
- a GIVE UP statement by line label will have no effect. Note
- that this insures that DON'T GIVE UP will always be a "do-
- nothing" statement.
-
- _\b4_\b._\b4_\b._\b1_\b1 _\bG_\bI_\bV_\bE _\bU_\bP
-
- PLEASE GIVE UP is used to exit from a program. It has the
- effect of a PLEASE RESUME #80. DON'T GIVE UP, as noted in
- section , is effectively a null statement.
-
- _\b4_\b._\b4_\b._\b1_\b2 _\bI_\bn_\bp_\bu_\bt
-
- Input is accomplished with the statement DO WRITE IN list,
- where list represents a string of variables and/or elements
- of arrays, separated by intersections. Numbers are
- represented on cards, each number on a separate card, by
- spelling out each digit (in English) and separating the
- digits with one or more spaces. A zero (0) may be spelled as
- either ZERO or OH. Thus the range of (32-bit) input values
- permissible extends from ZERO (or OH) through FOUR TWO NINE
- FOUR NINE SIX SEVEN TWO NINE FIVE. (For the convenience of
- aviators, C-INTERCAL accepts the spelling NINER for NINE. In
- the service of internationalization, C-INTERCAL also accepts
- input digits in Sanskrit, Basque, Tagalog, Classical
- Nahuatl, Georgian, Kwakiutl, and Volapuk.)
-
- Attempting to write in a value greater than or equal to SIX
- FIVE FIVE THREE SIX for a 16-bit variable will result in the
- error message, "DON'T BYTE OFF MORE THAN YOU CAN CHEW."
-
- (See also section
- for a description of C-INTERCAL's character I/O.)
-
- _\b4_\b._\b4_\b._\b1_\b3 _\bO_\bu_\bt_\bp_\bu_\bt
-
- Values may be output to the printer, one value per line, via
- the statement DO READ OUT list, where the list contains
- variables, array elements, and/or constants. Output is in
- the form of "extended" Roman numerals (also called
- "butchered" Roman numerals), with an overline indicating the
- value below is "times 1000", and lower-case letters
- indicating "times 1000000". Zero is indicated by an overline
- with no character underneath. Thus, the range of (32-bit)
- output values possible is from
- _
-
- through
- __ ____________
- ivccxcivCMLXVIICCXCV.
- Note: For values whose residues modulo 1000000 are less than
- 4000, M is used to represent 1000; for values whose residues
-
-
-
-
-
-
-
-
- - 24 -
-
-
-
- are 4000 or greater,
- _
- I
- is used. Thus #3999 would read out as MMMCMXCIX 3 while
- #4000 would readout as
- __
- IV
- Similar rules apply to the use of
- _
- M
- and i for 1000000, and to that of m and
- _
- i
- for 1000000000.
-
- (See also section
- for a description of C-INTERCAL's character I/O.)
-
- _\b4_\b._\b4_\b._\b1_\b4 _\bC_\bO_\bM_\bE _\bF_\bR_\bO_\bM
-
- In which we try to precisely define a statement that should
- never have been born, but is nevertheless one of the more
- useful statements in INTERCAL.
-
- _\b4_\b._\b4_\b._\b1_\b4_\b._\b1 _\bB_\ba_\bc_\bk_\bg_\br_\bo_\bu_\bn_\bd
-
- The earliest known description of the COME FROM statement in
- the computing literature is in [R. L. Clark, "A linguistic
- contribution to GOTO-less programming," Commun. ACM 27
- (1984), pp. 349-350], part of the famous April Fools issue
- of CACM. The subsequent rush by language designers to
- include the statement in their languages was underwhelming,
- one might even say nonexistent. It was therefore decided
- that COME FROM would be an appropriate addition to C-
- INTERCAL.
-
- _\b4_\b._\b4_\b._\b1_\b4_\b._\b2 _\bD_\be_\bs_\bc_\br_\bi_\bp_\bt_\bi_\bo_\bn
-
- There are two useful ways to visualize the action of the
- COME FROM statement. The simpler is to see that it acts like
- a GOTO when the program is traced backwards in time. More
- precisely, the statements
-
- (1) DO <any statement>
- .
- .
- .
- (2) DO COME FROM (1)
-
- ____________________
-
- 3. The original INTERCAL-72 manual claimed that #3999 should
- render as MMMIM, but the C-INTERCAL developers have been
- unable to find an algorithm that does this and is
- consistent with the rest of the rules.
-
-
-
-
-
-
-
- - 25 -
-
-
-
- should be thought of as being equivalent to
-
- (1) DO <any statement>
- (2) DO GOTO (3)
- .
- .
- .
- (3) DO NOTHING
-
- if INTERCAL actually had a GOTO statement at all, which of
- course it doesn't.
-
- What this boils down to is that the statement DO COME FROM
- (label), anywhere in the program, places a kind of invisible
- trap door immediately after statement (label). Execution or
- abstention of that statement is immediately followed by an
- unconditional jump to the COME FROM, unless the (label)ed
- statement is an executed NEXT, in which case the jump occurs
- if the program attempts to RESUME back to that NEXT
- statement. It is an error for more than one COME FROM to
- refer to the same (label).
-
- Modification of the target statement by ABSTAIN or by the %
- qualifier affects only that statement, not the subsequent
- jump. Such modifications to the COME FROM itself, however,
- do affect the jump. Encountering the COME FROM statement
- itself, rather than its target, has no effect.
-
- _\b4_\b._\b5 _\bC_\bo_\bm_\bm_\be_\bn_\bt_\bs
-
- Unrecognizable statements, as noted in section , are flagged
- with a splat (*) during compilation, and are not considered
- fatal errors unless they are encountered during execution,
- at which time the statement (as input at compilation time)
- is printed and execution is terminated. This allows for an
- interesting (and, by necessity, unique) means of including
- comments in an INTERCAL listing. For example, the statement:
-
- * PLEASE NOTE THAT THIS LINE HAS NO EFFECT
-
- will be ignored during execution due to the inclusion of the
- NOT qualifier. User-supplied error messages are also easy
- to implement:
-
- * DO SOMETHING ABOUT OVERFLOW IN ;3
-
- as are certain simple conditional errors:
-
- * (123) DON'T YOU REALIZE THIS STATEMENT SHOULD ONLY BE ENCOUNTERED
- ONCE?
- PLEASE REINSTATE (123)
-
- This pair of statements will cause an error exit the second
- time they are encountered. Caution!! The appearance of a
-
-
-
-
-
-
-
-
- - 26 -
-
-
-
- statement identifier in an intended comment will be taken as
- the beginning of a new statement. Thus, the first comment
- example above could not have been:
-
- * PLEASE NOTE THAT THIS LINE DOES NOTHING
-
- The third example, however, is valid, despite the appearance
- of two cases of D-space-O, since INTERCAL does not ignore
- extraneous spaces in statement identifiers.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 27 -
-
-
-
- _\b5_\b. _\bO_\bU_\bT_\bS_\bI_\bD_\bE _\bC_\bO_\bM_\bM_\bU_\bN_\bI_\bC_\bA_\bT_\bI_\bO_\bN
-
-
- She puzzled over this for some time, but at last a bright
- thought struck her. "Why, it's a Looking-glass book, of
- course! And, if I hold it up to a glass, the words will all
- go the right way again."
-
-
- In which we try to remedy the fact that, due to I/O
- limitations, INTERCAL can not even in principle perform the
- same tasks as other languages. It is hoped that this
- addition will permit INTERCAL users to waste vast quantities
- of computer time well into the 21st century.
-
- _\b5_\b._\b1 _\bM_\bo_\bt_\bi_\bv_\ba_\bt_\bi_\bo_\bn
-
- One of the goals of INTERCAL was to provide a language
- which, though different from all other languages, is
- nevertheless theoretically capable of all the same tasks.
- INTERCAL-72 failed to accomplish this because its I/O
- functions could not handle arbitrary streams of bits, or
- even arbitrary sequences of characters. A language which
- can't even send its input directly to its output can hardly
- be considered as capable as other languages.
-
- _\b5_\b._\b2 _\bT_\bu_\br_\bi_\bn_\bg _\bT_\be_\bx_\bt _\bM_\bo_\bd_\be_\bl
-
- To remedy this problem, character I/O is now provided in a
- form based on the "Turing Text" model, originally proposed
- by Jon Blow. The C-INTERCAL programmer can access this
- capability by placing a one-dimensional array in the list of
- items given to a WRITE IN or READ OUT statement. On
- execution of the statement, the elements of the array will,
- from first to last, be either loaded from the input or sent
- to the output, as appropriate, in the manner described
- below. There is currently no support for I/O involving
- higher-dimensional arrays, but some form of graphics might
- be a possible 2-D interpretation.
-
- The heart of the Turing Text model is the idea of a
- continuous loop of tape containing, in order, all the
- characters in the machine's character set. When a character
- is received by the input routine, the tape is advanced the
- appropriate number of spaces to bring that character under
- the tape head, and the number of spaces the tape was moved
- is the number that is actually seen by the INTERCAL program.
- Another way to say this is that the number placed in an
- INTERCAL array is the difference between the character just
- received and the previous character, modulo the number of
- characters in the machine character set.
-
- Output works in just the opposite fashion, except that the
- characters being output come from the other side of the
-
-
-
-
-
-
-
-
- - 28 -
-
-
-
- tape. From this position the characters on the tape appear
- to be in reverse order, and are individually backwards as
- well. (We would show you what it looks like, but we don't
- have a font with backwards letters available. Use your
- imagination.) The effect is that a number is taken out of an
- INTERCAL array, subtracted from the last character output --
- i.e., the result of the last subtraction -- and then sent on
- down the output channel. The only catch is that the
- character as seen by the INTERCAL program is the mirror-
- image of the character as seen by the machine and the user.
- The bits of the character are therefore taken in reverse
- order as it is sent to the output. Note that this bit
- reversal affects only the character seen by the outside
- world; it does not affect the character stored internally by
- the program, from which the next output number will be
- subtracted. All subtractions are done modulo the number of
- characters in the character set.
-
- Two different tapes are used for input and output to allow
- for future expansion of the language to include multiple
- input and output channels. Both tapes start at character 0
- when a program begins execution. On input, when an end-of-
- file marker is reached the number placed in the array is one
- greater than the highest-numbered character on the tape.
-
- _\b5_\b._\b3 _\bE_\bx_\ba_\bm_\bp_\bl_\be _\bP_\br_\bo_\bg_\br_\ba_\bm
-
- If all this seems terribly complicated, it should be made
- perfectly clear by the following example program, which
- simply maps its input to its output (like a simplified UNIX
- "cat"). It assumes that characters are 8 bits long, but
- that's fine since the current version of C-INTERCAL does
- too. It uses the standard library routines for addition and
- subtraction.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 29 -
-
-
-
- DO ,1 <- #1
- DO .4 <- #0
- DO .5 <- #0
- DO COME FROM (30)
- DO WRITE IN ,1
- DO .1 <- ,1SUB#1
- DO (10) NEXT
- PLEASE GIVE UP
- (20) PLEASE RESUME '?.1$#256'~'#256$#256'
- (10) DO (20) NEXT
- DO FORGET #1
- DO .2 <- .4
- DO (1000) NEXT
- DO .4 <- .3~#255
- DO .3 <- !3~#15'$!3~#240'
- DO .3 <- !3~#15'$!3~#240'
- DO .2 <- !3~#15'$!3~#240'
- DO .1 <- .5
- DO (1010) NEXT
- DO .5 <- .2
- DO ,1SUB#1 <- .3
- (30) PLEASE READ OUT ,1
-
- For each number received in the input array, the program
- first tests the #256 bit to see if the end of file has been
- reached. If not, the previous input character is subtracted
- off to obtain the current input character. Then the order of
- the bits is reversed to find out what character should be
- sent to the output, and the result is subtracted from the
- last character sent. Finally, the difference is placed in an
- array and given to a READ OUT statement. See? We told you
- it was simple!
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 30 -
-
-
-
- _\b6_\b. _\bT_\br_\bi_\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL
-
-
- "-- oh dear, how puzzling it all is! I'll try if I know all
- the things I used to know. Let me see: four times five is
- twelve, and four times six is thirteen, and four times seven
- is -- oh dear! I shall never get to twenty at that rate!"
-
-
- In which it is revealed that bitwise operations are too
- ordinary for hard-core INTERCAL programmers, and extensions
- to other bases are discussed. These are not, strictly
- speaking, extensions to INTERCAL itself, but rather new
- dialects sharing most of the features of the parent
- language.
-
- _\b6_\b._\b1 _\bM_\bo_\bt_\bi_\bv_\ba_\bt_\bi_\bo_\bn
-
- INTERCAL is really a pretty sissy language. It tries hard to
- be different, but when you get right down to its roots, what
- do you find? You find bits, that's what. Plain old ones and
- zeroes, in groups of 16 and 32, just like every other
- language you've ever heard of. And what operations can you
- perform on these bits? The INTERCAL operators may arrange
- and permute them in weird and wonderful ways, but at the bit
- level the operators are the same AND, OR and XOR you've seen
- countless times before.
-
- Once the prospective INTERCAL programmer masters the unusual
- syntax, she finds herself working with the familiar Boolean
- operators on perfectly ordinary unsigned integer words. Even
- the constants she uses are familiar. After all, who would
- not immediately recognize #65535 and #32768? It may take a
- just a moment more to figure out #65280, and #21845 and
- #43690 could be puzzles until she notices that they sum to
- #65535, but basically she's still on her home turf. The
- 16-bit limit on constants actually works in the programmer's
- favor by insuring that very long anonymous constants cannot
- appear in INTERCAL programs. And this is in a language that
- is supposed to be different from any other!
-
- _\b6_\b._\b2 _\bA_\bb_\ba_\bn_\bd_\bo_\bn _\bA_\bl_\bl _\bH_\bo_\bp_\be_\b._\b._\b.
-
- Standard INTERCAL is based on variables consisting of
- ordinary bits and familiar Boolean operations on those bits.
- In pursuit of uniqueness, it seems appropriate to provide a
- new dialect, otherwise identical to INTERCAL, which instead
- uses variables consisting of trits, i.e. ternary digits, and
- operators based on tritwise logical operations. This is
- intended to be a separate dialect, rather than an extension
- to INTERCAL itself, for a number of reasons. Doing it this
- way avoids word-length conflicts, does not spoil the
- elegance of the Spartan INTERCAL operator set, and dodges
- the objections of those who might feel it too great an
-
-
-
-
-
-
-
-
- - 31 -
-
-
-
- alteration to the original language. Primarily, though,
- giving INTERCAL programmers the ability to switch numeric
- base at will amounts to excessive functionality. So much
- better that a programmer choose a base at the outset and
- then be forced to stick with it for the remainder of the
- program.
-
- _\b6_\b._\b3 _\bC_\bo_\bm_\bp_\bi_\bl_\be_\br _\bO_\bp_\be_\br_\ba_\bt_\bi_\bo_\bn
-
- The same compiler, ick, supports both INTERCAL and
- TriINTERCAL. This has the advantage that future bug fixes
- and additions to the language not related to arithmetic
- immediately apply to both versions. The compiler recognizes
- INTERCAL source files by the extension '.i', and TriINTERCAL
- source files by the extension '.3i'. It's as simple as that.
- There is no way to mix INTERCAL and TriINTERCAL source in
- the same program, and it is not always possible to determine
- which dialect a program is written in just by looking at the
- source code.
-
- _\b6_\b._\b4 _\bD_\ba_\bt_\ba _\bT_\by_\bp_\be_\bs
-
- The two TriINTERCAL data types are 10-trit unsigned integers
- and 20-trit unsigned integers. All INTERCAL syntax for
- distinguishing data types is ported to these new types in
- the obvious way. Small words may contain numbers from #0 to
- #59048; large words may contain numbers from #0$#0 to
- #59048$#59048. Errors are signaled for constants greater
- than #59048 and for attempts to WRITE IN numbers too large
- for a given variable or array element to hold.
-
- Note that though TriINTERCAL considers all numbers to be
- unsigned, nothing prevents the programmer from implementing
- arithmetic operations that treat their operands as signed.
- Three's complement is one obvious choice, but balanced
- ternary notation is also a possibility. This latter is a
- very pretty and symmetrical system in which all 2 trits are
- treated as if they had the value -1.
-
- _\b6_\b._\b5 _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- The TriINTERCAL operators are designed to inherit the
- relevant properties of the standard INTERCAL operators, so
- that both can be considered as merely different aspects of
- the same Platonic ideal. (Not that the word "ideal" is ever
- particularly relevant when used in connection with
- INTERCAL.)
-
- _\b6_\b._\b5_\b._\b1 _\bB_\bi_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs _\bI
-
- The binary operators carry over from the original language
- with only minor changes. The mingle operator ($) creates a
- 20-trit word by alternating trits from its two 10-trit
- operands. The select operator (~) is a little more
-
-
-
-
-
-
-
-
- - 32 -
-
-
-
- complicated, since the ternary tritmask may contain 0, 1,
- and 2 trits. If we observe that the select operation on
- binary operands amounts to a bitwise AND and some
- rearrangement of bits, it seems appropriate to base the
- select for ternary operands on a tritwise AND in the
- analogous fashion. We therefore postpone the definition of
- select until we know what a tritwise AND looks like.
-
- _\b6_\b._\b5_\b._\b2 _\bU_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- The unary operators in INTERCAL are all derived from the
- familiar Boolean operations on single bits. To extend these
- operations to trits, we first ask ourselves what the
- important properties of these operations are that we wish to
- be preserved, then design the tritwise operators so that
- they behave in a similar fashion.
-
- _\b6_\b._\b5_\b._\b2_\b._\b1 _\bU_\bn_\ba_\br_\by _\bL_\bo_\bg_\bi_\bc_\ba_\bl _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- Let's start with AND and OR. To begin with, these can be
- considered "choice" or "preference" operators, as they
- always return one of their operands. AND can be described as
- wanting to return 0, but returning 1 if it is given no other
- choice, i.e., if both operands are 1. Similarly, OR wants to
- return 1 but returns 0 if that is its only choice. From this
- it is immediately apparent that each operator has an
- identity element that "always loses", and a dominator
- element that "always wins".
-
- AND and OR are commutative and associative, and each
- distributes over the other. They are also symmetric with
- each other, in the sense that AND looks like OR and OR looks
- like AND when the roles of 0 and 1 are interchanged (De
- Morgan's Laws). This symmetry property seems to be a key
- element to the idea that these are logical, rather than
- arithmetic, operators. In a three-valued logic we would
- similarly expect a three-way symmetry among the three values
- 0, 1 and 2 and the three operators AND, OR and (of course)
- BUT.
-
- The following tritwise operations have all the desired
- properties: OR returns the greater of its two operands. That
- is, it returns 2 if it can get it, else it tries to return
- 1, and it returns 0 only if both operands are 0. AND wants
- to return 0, will return 2 if it can't get 0, and returns 1
- only if forced. BUT wants 1, will take 0, and tries to avoid
- 2. The equivalents to De Morgan's Laws apply to rotations of
- the three elements, e.g., 0 -> 1, 1 -> 2, 2 -> 0. Each
- operator distributes over exactly one other operator, so the
- property "X distributes over Y" is not transitive. The
- question of which way this distributivity ring goes around
- is left as an exercise for the student.
-
- In TriINTERCAL programs the whirlpool (@) denotes the unary
-
-
-
-
-
-
-
-
- - 33 -
-
-
-
- tritwise BUT operation. You can think of the whirlpool as
- drawing values preferentially towards the central value 1.
- Alternatively, you can think of it as drawing your soul and
- your sanity inexorably down ...
-
- On the other hand, maybe it's best you _\bn_\bo_\bt think of it that
- way.
-
- A few comments about how these operators can be used. OR
- acts like a tritwise maximum operation. AND can be used with
- tritmasks. 0's in a mask wipe out the corresponding elements
- in the other operand, while 1's let the corresponding
- elements pass through unchanged. 2's in a mask consolidate
- the values of nonzero elements, as both 1's and 2's in the
- other operand yield 2's in the output. BUT can be used to
- create "partial tritmasks". 0's in a mask let BUT eliminate
- 2's from the other operand while leaving other values
- unchanged. Of course, the symmetry property guarantees that
- the operators don't really behave differently from each
- other in any fundamental way; the apparent differences come
- from the intuitive view that a 0 trit is "not set" while a 1
- or 2 trit is "set".
-
- _\b6_\b._\b5_\b._\b2_\b._\b2 _\bB_\bi_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs _\bI_\bI
-
- At this point we can define select, since we now know what
- the tritwise AND looks like. Select takes the binary
- tritwise AND of its two operands. It shifts all the trits of
- the result corresponding to 2's in the right operand over to
- the right (low) end of the result, then follows them with
- all the output trits corresponding to 1's in the right
- operand. Trits corresponding to 0's in the right operand,
- which are all 0 anyway, occupy the remaining space at the
- left end of the output word. Both 10-trit and 20-trit
- operands are accepted, and are padded with zeroes on the
- left if necessary. The output type is determined the same
- way as in standard C-INTERCAL.
-
- _\b6_\b._\b5_\b._\b2_\b._\b3 _\bU_\bn_\ba_\br_\by _\bA_\br_\bi_\bt_\bh_\bm_\be_\bt_\bi_\bc _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- Now that we've got all that settled, what about XOR? This is
- easily the most-useful of the three unary INTERCAL
- operators, because it combines in one package the operations
- ADD WITHOUT CARRY, SUBTRACT WITHOUT BORROW, BITWISE NOT-
- EQUAL, and BITWISE NOT. In TriINTERCAL we can't have all of
- these in the same operator, since addition and subtraction
- are no longer the same thing. The solution is to split the
- XOR concept into two operators. The ADD WITHOUT CARRY
- operation is represented by the new sharkfin (^), while the
- old what (?) represents SUBTRACT WITHOUT BORROW. The reason
- for this choice is so that what (?) will also represent the
- TRITWISE NOT-EQUAL operation.
-
- Note that what (?), unlike the other four unary operators,
-
-
-
-
-
-
-
-
- - 34 -
-
-
-
- is not symmetrical. It should be thought of as rotating its
- operand one trit to the right (with wraparound) and then
- subtracting off the trits of the original number. These
- subtractions are done without borrowing, i.e., trit-by-trit
- modulo 3.
-
- _\b6_\b._\b5_\b._\b3 _\bE_\bx_\ba_\bm_\bp_\bl_\be_\bs
-
- The TriINTERCAL operators really aren't all that bad once
- you get used to them. Let's look at a few examples to show
- how they can be used in practice. In all of these examples
- the input value is contained in the 10-trit variable .3.
-
- In INTERCAL, single-bit values often have to be converted
- from {0,1} to {1,2} for use in RESUME statements. Examples
- of how to do this appear in the original manual. In
- TriINTERCAL the expression "^.3$#1"~#1 sends 0 -> 1 and 1 ->
- 2. If the 1-trit input value can take on any of its three
- possible states, however, we will also have to deal with the
- 2 case. The expression "V.3$#1"~#1 sends {0,1} -> 1 and 2 ->
- 2. To test if a trit is set, we can use
- "V'"&.3$#2"~#1'$#1"~#1, sending 0 -> 1 and {1,2} -> 2. To
- reverse the test we use "?'"&.3$#2"~#1'$#1"~#1, sending 0 ->
- 2 and {1,2} -> 1. Note that we have not been taking full
- advantage of the new select operator. These last two
- expressions can be simplified into "V!3~#2'$#1"~#1 and
- "?!3~#2'$#1"~#1, which perform exactly the same mappings.
- Finally, if we need a 3-way test, we can use
- "@'"^.3$#7"~#4'$#2"~#10, which obviously sends 0 -> 1, 1 ->
- 2, and 2 -> 3.
-
- For an unrelated example, the expression
- "^.3$.3"~"#0$#29524" converts all of the 1-trits of .3 into
- 2's and all of the 2-trits into 1's. In balanced ternary,
- where 2-trits represent -1 values, this is the negation
- operation.
-
- _\b6_\b._\b6 _\bB_\be_\by_\bo_\bn_\bd _\bT_\be_\br_\bn_\ba_\br_\by_\b._\b._\b.
-
- While we're at it, we might as well extend this multiple
- bases business a little farther. The ick compiler actually
- recognizes filename suffixes of the form '.Ni', where N is
- any number from 2 to 7. 2 of course gives standard INTERCAL,
- while 3 gives TriINTERCAL. We cut off before 8 because
- octal notation is the smallest base used to facilitate
- human-to-machine communication, and this seems quite
- contrary to the basic principles behind INTERCAL. The small
- data types hold 16 bits, 10 trits, 8 quarts, 6 quints, 6
- sexts, or 5 septs, and the large types are always twice this
- size.
-
- As for operators, ? is always SUBTRACT WITHOUT BORROW, and ^
- is always ADD WITHOUT CARRY. V is the OR operation and
- always returns the max of its inputs. & is the AND
-
-
-
-
-
-
-
-
- - 35 -
-
-
-
- operation, which chooses 0 if possible but otherwise returns
- the max of the inputs. @ is BUT, which prefers 1, then 0,
- then the max of the remaining possibilities. Rather than
- add more special symbols forever, a numeric modifier may be
- placed directly before the @ to indicate the operation that
- prefers one of the digits not already represented. Thus in
- files ending in '.5i', the permitted unary operators are ?,
- ^, &, @, 2@, 3@, and V. Use of such barbarisms as 0@ to
- represent & are not permitted, nor is the use of @ or ^ in
- files with either of the extensions '.i' or '.2i'. Why not?
- You just can't, that's why. Don't ask so many questions.
-
- As a closing example, we note that in balanced quinary
- notation, where 3 means -2 and 4 means -1, the negation
- operation can be written as either
-
- DO .1 <- "^'"^.3$.3"~"#0$#3906"'$'"^.3$.3"~"#0$#3906"'"~"#0$#3906"
-
- or as
-
- DO .1 <- "^.3$.3"~"#0$#3906"
- DO .1 <- "^.1$.1"~"#0$#3906"
-
- These work because multiplication by -1 is the same as
- multiplication by 4, modulo 5.
-
- Now go beat your head against the wall for a while.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 36 -
-
-
-
- _\b7_\b. _\bS_\bU_\bB_\bR_\bO_\bU_\bT_\bI_\bN_\bE _\bL_\bI_\bB_\bR_\bA_\bR_\bY
-
-
- "You don't know what you're talking about!" cried Humpty
- Dumpty. "How many days are there in a year?"
-
- "Three hundred and sixty-five," said Alice.
-
- "And how many birthdays have you?"
-
- "One."
-
- "And if you take one from three hundred and sixty-five, what
- remains?"
-
- "Three hundred and sixty-four, of course."
-
- Humpty Dumpty looked doubtful. "I'd rather see that done on
- paper," he said.
-
-
- INTERCAL provides several built-in subroutines to which
- control can be transferred to perform various operations.
- These operations include many useful functions which are not
- easily representable in INTERCAL, such as addition,
- subtraction, etc.
-
- _\b7_\b._\b1 _\bU_\bs_\ba_\bg_\be
-
- In general, the operands are .1, .2, etc., or :1, :2, etc.,
- and the result(s) are stored in what would have been the
- next operand(s). For instance, one routine adds .1 to .2 and
- stores the sum in .3, with .4 being used to indicate
- overflow. All variables not used for results are left
- unchanged.
-
- _\b7_\b._\b2 _\bA_\bv_\ba_\bi_\bl_\ba_\bb_\bl_\be _\bF_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\bs
-
- At the time of this writing, only the most fundamental
- operations are offered in the library, as a more complete
- selection would require prohibitive time and core to
- implement. These functions, along with their corresponding
- entry points (entered via DO (entry) NEXT) are listed below.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 37 -
-
-
-
- (1000) .3 <- .1 plus .2, error exit on overflow
- (1009) .3 <- .1 plus .2
- .4 <- #1 if no overflow, else .4 <- #2
- (1010) .3 <- .1 minus .2, no action on overflow
- (1020) .1 <- .1 plus #1, no action on overflow
- (1030) .3 <- .1 times .2, error exit on overflow
- (1039) .3 <- .1 times .2
- .4 <- #1 if no overflow, else .4 <- #2
- (1040) .3 <- .1 divided by .2
- .3 <- #0 if .2 is #0
- (1050) .2 <- :1 divided by .1, error exit on overflow
- .2 <- #0 if .1 is #0
-
- (1500) :3 <- :1 plus :2, error exit on overflow
- (1509) :3 <- :1 plus :2
- :4 <- #1 if no overflow, else :4 <- #2
- (1510) :3 <- :1 minus :2, no action on overflow
- (1520) :1 <- .1 concatenated with .2
- (1525) This subroutine is intended solely for internal
- use within the subroutine library and is therefore
- not described here. Its effect is to shift .3
- logically 8 bits to the left.
- (1530) :1 <- .1 times .2
- (1540) :3 <- :1 times :2, error exit on overflow
- (1549) :3 <- :1 times :2
- :4 <- #1 if no overflow, else :4 <- #2
- (1550) :3 <- :1 divided by :2
- :3 <- #0 if :2 is #0
-
- (1900) .1 <- uniform random no. from #0 to #65535
- (1910) .2 <- normal random no. from #0 to .1, with
- standard deviation .1 divided by #12
-
-
- _\b7_\b._\b3 _\bA_\bu_\bt_\bo_\bm_\ba_\bg_\bi_\bc_\ba_\bl _\bI_\bn_\bc_\bl_\bu_\bs_\bi_\bo_\bn _\bO_\bf _\bT_\bh_\be _\bS_\bu_\bb_\br_\bo_\bu_\bt_\bi_\bn_\be _\bL_\bi_\bb_\br_\ba_\br_\by
-
- The C-INTERCAL compiler will automatically include the
- system library if a DO (1xxx) NEXT statement is used, and if
- no (1xxx) labels are defined anywhere, where (1xxx) is a
- label in the 1000-1999 range, inclusive. This was not an
- INTERCAL-72 feature.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 38 -
-
-
-
- _\b8_\b. _\bP_\bR_\bO_\bG_\bR_\bA_\bM_\bM_\bI_\bN_\bG _\bH_\bI_\bN_\bT_\bS
-
-
- "If any one of them can explain it," said Alice, "I'll give
- him sixpence. _\bI don't believe there's an atom of meaning in
- it." The jury all wrote down, on their slates, "_\bS_\bh_\be doesn't
- believe there's an atom of meaning in it," but none of them
- attempted to explain the paper.
-
- "If there's no meaning in it," said the King, "that saves a
- world of trouble, you know, as we needn't try to find any.
- And yet, I don't know," he went on, spreading out the verses
- on one knee, and looking at them with one eye: "I seem to
- see some meaning in them, after all...."
-
-
- For the user looking to become more familiar with the
- INTERCAL language, we present in this section an analysis of
- a complex program, as well as some suggested projects for
- the ambitious programmer.
-
- Considering the effort involved in writing an INTERCAL
- program, it was decided in putting together this manual to
- use an already existing program for instructive analysis.
- Since there was only one such program available, we have
- proceeded to use it. It is known as the "INTERCAL System
- Library."
-
- _\b8_\b._\b1 _\bD_\be_\bs_\bc_\br_\bi_\bp_\bt_\bi_\bo_\bn
-
- The program listing is in section . It is in the same format
- as would be produced by the Princeton INTERCAL compiler in
- FORMAT mode with WIDTH=62 (see section ). For a description
- of the functions performed by the Library, see section .
-
- _\b8_\b._\b2 _\bA_\bn_\ba_\bl_\by_\bs_\bi_\bs
-
- We shall not attempt to discuss here the algorithms used,
- but rather we shall point out some of the general techniques
- applicable to a wide range of problems.
-
- Statements 10, 14, 15, and 26 make up a virtual "computed GO
- TO". When statement 10 is executed, control passes
- eventually to statement 16 or 11, depending on whether .5
- contains #1 or #2, respectively. The value of .5 is
- determined in statement 9, which demonstrates another handy
- technique. To turn an expression, exp, with value #0 or #1,
- into #1 or #2 (for use in a "GO TO"), use "V\b-'exp'c\b/#1"~#3.
- To reverse the condition (i.e., convert #0 to #2 and leave
- #1 alone) use "V\b-'exp'c\b/#2"~#3.
-
- Certain conditions are easily checked. For example, to test
- for zero, select the value from itself and select the bottom
- bit (see statement 54). To test for all bits being 1's,
-
-
-
-
-
-
-
-
- - 39 -
-
-
-
- select the value from itself and select the top bit. The
- test for greater than, performed in statements 219 and 220
- on 32-bit values, employs binary logical operations, which
- are performed as follows:
-
- 'V\b-.1c\b/.2'~'#0c\b/#65535'
-
- for 16-bit values or, for 32-bit values:
-
- "'V\b-":1~'#65535c\b/30'"c\b/":2~'#65535c\b/#0'"'~'#0
- c\b/#65535'"c\b/"'V\b-":1~'#0c\b/#65535'"c\b/":2~'#0
- c\b/#65535'"'~'#0c\b/#65535'"
-
- (The proofs are left as an exercise to the reader.)
-
- Testing for greater-than with 16-bit values is somewhat
- simpler and is done with the pair of statements:
-
- DO .C <- 'V\b-.Ac\b/.B'~'#0c\b/#65535'
- DO .C <- '&"'.A~.C'~'"V\b-'V\b-.C~.C'c\b/#32768"
- ~"#0c\b/#65535"'"c\b/".C~.C"'~#1
-
- This sets .C (a dummy variable) to #1 if .A > .B, and #0
- otherwise. The expression may be expanded as described above
- to instead set .C to #1 or #2.
-
- Note also in statement 220 the occurrence of
- ~"#65535c\b/#65535". Although these operations select the
- entire value, they are not extraneous, as they ensure that
- the forthcoming V\b-s will be operating on 32-bit values.
-
- In several virtual computed GO TOs the DO FORGET #1
- (statement 15 in the earlier example) has been omitted,
- since the next transfer of control would be a DO RESUME #1.
- By making this a DO RESUME #2 instead, the FORGET may be
- forgotten.
-
- In statement 64, note that .2 is STASHed twice by a single
- statement. This is perfectly legal.
-
- Lastly, note in statements 243 and 214 respectively,
- expressions for shifting 16- and 32-bit variables logically
- one place to the left. Statement 231 demonstrates right-
- shifting for 32-bit variables.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 40 -
-
-
-
- _\b8_\b._\b3 _\bP_\br_\bo_\bg_\br_\ba_\bm _\bL_\bi_\bs_\bt_\bi_\bn_\bg
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 41 -
-
-
-
- 1 (1000) PLEASE IGNORE .4
- 2 PLEASE ABSTAIN FROM (1005)
- 3 (1009) DO STASH .1 + .2 + .5 + .6
- 4 DO .4 <- #1
- 5 DO (1004) NEXT
- 6 (1004) PLEASE FORGET #1
- 7 DO .3 <- 'V\b-.1c\b/.2'~'#0c\b/#65535'
- 8 DO .6 <- '&.1c\b/.2'~'#0c\b/#65535'
- 9 PLEASE DO .5 <- "V\b-!6~#32768'c\b/#1"~#3
- 10 DO (1002) NEXT
- 11 DO .4 <- #2
- 12 (1005) DO (1006) NEXT
- * 13 (1999) DOUBLE OR SINGLE PRECISION OVERFLOW
- 14 (1002) DO (1001) NEXT
- 15 (1006) PLEASE FORGET #1
- 16 DO .5 <- 'V\b-"!6~.6'~#1"c\b/#1'~#3
- 17 DO (1003) NEXT
- 18 DO .1 <- .3
- 19 DO .2 <- !6c\b/#0'~'#32767c\b/#1'
- 20 DO (1004) NEXT
- 21 (1003) DO (1001) NEXT
- 22 DO REINSTATE (1005)
- 23 (1007) PLEASE RETRIEVE .1 + .2 + .5 + .6
- 24 DO REMEMBER .4
- 25 PLEASE RESUME #2
- 26 (1001) DO RESUME .5
- 27 (1010) DO STASH .1 + .2 + .4
- 28 DO .4 <- .1
- 29 DO .1 <- 'V\b-.2c\b/#65535'~'#0c\b/#65535'
- 30 DO (1020) NEXT
- 31 PLEASE DO .2 <- .4
- 32 PLEASE DO (1009) NEXT
- 33 DO RETRIEVE .1 + .2 + .4
- 34 PLEASE RESUME #1
- 35 (1020) DO STASH .2 + .3
- 36 DO .2 <- #1
- 37 PLEASE DO (1021) NEXT
- 38 (1021) DO FORGET #1
- 39 DO .3 <- "V\b-!1~.2'c\b/#1"~#3
- 40 PLEASE DO .1 <- 'V\b-.1c\b/.2'~'#0c\b/#65535'
- 41 DO (1022) NEXT
- 42 DO .2 <- !2c\b/#0'~'#32767c\b/#1'
- 43 DO (1021) NEXT
- 44 (1023) PLEASE RESUME .3
- 45 (1022) DO (1023) NEXT
- 46 PLEASE RETRIEVE .2 + .3
- 47 PLEASE RESUME #2
- 48 (1030) DO ABSTAIN FROM (1033)
- 49 PLEASE ABSTAIN FROM (1032)
- 50 (1039) DO STASH :1 + .5
- 51 DO (1530) NEXT
- 52 DO .3 <- :1~#65535
- 53 PLEASE DO .5 <- :1~'#65280c\b/#65280'
- 54 DO .5 <- 'V\b-"!5~.5'~#1"c\b/#1'~#3
-
-
-
-
-
-
-
-
- - 42 -
-
-
-
- 55 DO (1031) NEXT
- 56 (1032) DO (1033) NEXT
- 57 DO (1999) NEXT
- 58 (1031) DO (1001) NEXT
- 59 (1033) DO .4 <- .5
- 60 DO REINSTATE (1032)
- 61 PLEASE REINSTATE (1033)
- 62 DO RETRIEVE :1 + .5
- 63 PLEASE RESUME #2
- 64 (1040) PLEASE STASH .1 + .2 + .2 + :1 + :2 + :3
- 65 DO .2 <- #0
- 66 DO (1520) NEXT
- 67 DO STASH :1
- 68 PLEASE RETRIEVE .2
- 69 DO .1 <- .2
- 70 DO .2 <- #0
- 71 PLEASE DO (1520) NEXT
- 72 DO :2 <- :1
- 73 DO RETRIEVE .1 + .2 + :1
- 74 DO (1550) NEXT
- 75 PLEASE DO .3 <- :3
- 76 DO RETRIEVE :1 + :2 + :3
- 77 DO RESUME #1
- 78 (1050) PLEASE STASH :2 + :3 + .5
- 79 DO :2 <- .1
- 80 PLEASE DO (1550) NEXT
- 81 DO .5 <- :3~'#65280c\b/#65280'
- 82 DO .5 <- 'V\b-"!5~.5'~#1"c\b/#1'~#3
- 83 DO (1051) NEXT
- 84 DO (1999) NEXT
- 85 (1051) DO (1001) NEXT
- 86 DO .2 <- :3
- 87 PLEASE RETRIEVE :2 + :3 + .5
- 88 DO RESUME #2
- 89 (1500) PLEASE ABSTAIN FROM (1502)
- 90 PLEASE ABSTAIN FROM (1506)
- 91 (1509) PLEASE STASH :1 + .1 + .2 + .3 + .4 + .5 + .6
- 92 DO .1 <- :1~#65535
- 93 PLEASE DO .2 <- :2~#65535
- 94 DO (1009) NEXT
- 95 DO .5 <- .3
- 96 PLEASE DO .6 <- .4
- 97 DO .1 <- :1~'#65280c\b/#65280'
- 98 DO .2 <- :2~'#65280c\b/#65280'
- 99 DO (1009) NEXT
- 100 DO .1 <- .3
- 101 PLEASE DO (1503) NEXT
- 102 DO .6 <- .4
- 103 DO .2 <- #1
- 104 DO (1009) NEXT
- 105 DO .1 <- .3
- 106 DO (1501) NEXT
- 107 (1504) PLEASE RESUME .6
- 108 (1503) DO (1504) NEXT
-
-
-
-
-
-
-
-
- - 43 -
-
-
-
- 109 (1501) DO .2 <- .5
- 110 DO .5 <- 'V\b-"'&.6c\b/.4'~#1"c\b/#2'~#3
- 111 DO (1505) NEXT
- 112 (1506) DO (1502) NEXT
- 113 PLEASE DO (1999) NEXT
- 114 (1505) DO (1001) NEXT
- 115 (1502) DO :4 <- .5
- 116 DO (1520) NEXT
- 117 DO :3 <- :1
- 118 PLEASE RETRIEVE :1 + .1 + .2 + .3 + .4 + .5 + .6
- 119 DO REINSTATE (1502)
- 120 DO REINSTATE (1506)
- 121 PLEASE RESUME #3
- 122 (1510) DO STASH :1 + :2 + :4
- 123 DO :1 <- "'V\b-":2~'#65535c\b/#0'"c\b/#65535'
- ~'#0c\b/#65535'"c\b/"'V\b-":2~'#0c\b/#65535'
- "c\b/#65535'~'#0c\b/#65535'"
- 124 DO :2 <- #1
- 125 DO (1509) NEXT
- 126 PLEASE RETRIEVE :1
- 127 DO :2 <- :3
- 128 PLEASE DO (1509) NEXT
- 129 DO RETRIEVE :2 + :4
- 130 PLEASE RESUME #1
- 131 (1520) PLEASE STASH .3 + .4
- 132 DO .3 <- .1~#43690
- 133 DO (1525) NEXT
- 134 PLEASE DO .4 <- 'V.3c\b/".2~#43690"'~'#0c\b/#65535'
- 135 DO .3 <- .1~#21845
- 136 PLEASE DO (1525) NEXT
- 137 DO :1 <- .4c\b/"'V.3c\b/".2~#21845"'~'#0c\b/#65535'"
- 138 PLEASE RETRIEVE .3 + .4
- 139 DO RESUME #1
- 140 (1525) DO .3 <- '"'"'"!3c\b/#0'~'#32767c\b/#1'"c\b/#0'
- ~'#32767c\b/#1'"c\b/#0'~'#16383c\b/#3'"c\b/#0'
- ~'#4095c\b/#15'
- 141 PLEASE RESUME #1
- 142 (1530) DO STASH :2 + :3 + .3 + .5
- 143 DO :1 <- #0
- 144 DO :2 <- .2
- 145 DO .3 <- #1
- 146 DO (1535) NEXT
- 147 (1535) PLEASE FORGET #1
- 148 DO .5 <- "V\b-!1~.3'c\b/#1"~#3
- 149 DO (1531) NEXT
- 150 DO (1500) NEXT
- 151 DO :1 <- :3
- 152 PLEASE DO (1533) NEXT
- 153 (1531) PLEASE DO (1001) NEXT
- 154 (1533) DO FORGET #1
- 155 DO .3 <- !3c\b/#0'~'#32767c\b/#1'
- 156 DO :2 <- ":2~'#0c\b/#65535'"c\b/"'":2~'#32767
- c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- 157 PLEASE DO .5 <- "V\b-!3~.3'c\b/#1"~#3
-
-
-
-
-
-
-
-
- - 44 -
-
-
-
- 158 DO (1532) NEXT
- 159 DO (1535) NEXT
- 160 (1532) DO (1001) NEXT
- 161 PLEASE RETRIEVE :2 + :3 + .3 + .5
- 162 DO RESUME #2
- 163 (1540) PLEASE ABSTAIN FROM (1541)
- 164 DO ABSTAIN FROM (1542)
- 165 (1549) PLEASE STASH :1 + :2 + :4 + :5 + .1 + .2 + .5
- 166 DO .1 <- :1~#65535
- 167 PLEASE DO .2 <- :2~'#65280c\b/#65280'
- 168 DO .5 <- :1~'#65280c\b/#65280'
- 169 DO (1530) NEXT
- 170 DO :3 <- :1
- 171 DO .2 <- :2~#65535
- 172 PLEASE DO (1530) NEXT
- 173 DO :5 <- :1
- 174 DO .1 <- .5
- 175 DO (1530) NEXT
- 176 DO :4 <- :1
- 177 PLEASE DO :1 <- ":3~'#65280c\b/#65280'"
- c\b/":4~'#65280c\b/#65280'"
- 178 DO .5 <- ':1~:1'~#1
- 179 DO .2 <- :2~'#65280c\b/#65280'
- 180 DO (1530) NEXT
- 181 PLEASE DO .5 <- '"':1~:1'~#1"c\b/.5'~#3
- 182 DO .1 <- :3~#65535
- 183 DO .2 <- #0
- 184 DO (1520) NEXT
- 185 PLEASE DO :2 <- :1
- 186 PLEASE DO .1 <- :4~#65535
- 187 DO (1520) NEXT
- 188 DO (1509) NEXT
- 189 DO .5 <- !5c\b/":4~#3"'~#15
- 190 DO :1 <- :3
- 191 DO :2 <- :5
- 192 DO (1509) NEXT
- 193 PLEASE DO .5 <- !5c\b/":4~#3"'~#172
- 194 DO .5 <- 'V\b-"!5~.5'~#1"c\b/#1'~#3
- 195 PLEASE RETRIEVE :4
- 196 (1541) DO :4 <- .5
- 197 DO (1543) NEXT
- 198 (1542) DO (1544) NEXT
- 199 PLEASE DO (1999) NEXT
- 200 (1543) DO (1001) NEXT
- 201 (1544) DO REINSTATE (1541)
- 202 PLEASE REINSTATE (1542)
- 203 PLEASE RETRIEVE :1 + :2 + :5 + .1 + .2 + .5
- 204 DO RESUME #2
- 205 (1550) DO STASH :1 + :4 + :5 + .5
- 206 DO :3 <- #0
- 207 DO .5 <- 'V\b-"':2~:2'~#1"c\b/#1'~#3
- 208 PLEASE DO (1551) NEXT
- 209 DO :4 <- #1
- 210 PLEASE DO (1553) NEXT
-
-
-
-
-
-
-
-
- - 45 -
-
-
-
- 211 (1553) DO FORGET #1
- 212 DO .5 <- 'V\b-":2~'#32768c\b/#0'"c\b/#2'~#3
- 213 DO (1552) NEXT
- 214 DO :2 <- ":2~'#0c\b/#65535'"c\b/"'":2~'#32767
- c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- 215 PLEASE DO :4 <- ":4~'#0c\b/#65535'"c\b/"'":4
- ~'#32767c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- 216 DO (1553) NEXT
- 217 (1552) DO (1001) NEXT
- 218 (1556) PLEASE FORGET #1
- 219 DO :5 <- "'V\b-":1~'#65535c\b/#0'"c\b/":2
- ~'#65535c\b/#0'"'~'#0c\b/#65535'"c\b/"'
- V\b-":1~'#0c\b/#65535'"c\b/":2~'#0c\b/
- #65535'"'~'#0c\b/#65535'"
- 220 DO .5 <- 'V\b-"'&"':2~:5'~'"'V\b-"'V\b-":5~:5
- "~"#65535c\b/#65535"'~'#65535c\b/#0'"c\b/
- #32768'~'#0c\b/#65535'"c\b/"'V\b-":5~:5"
- ~"#65535c\b/#65535"'~'#0c\b/#65535'"'"c\b/"'
- :5~:5'~#1"'~#1"c\b/#2'~#3
- 221 DO (1554) NEXT
- 222 DO :5 <- :3
- 223 DO (1510) NEXT
- 224 PLEASE DO :1 <- :3
- 225 DO :3 <- "'V":4~'#65535c\b/#0'"c\b/":5~'#65535
- c\b/#0'"'~'#0c\b/#65535'"c\b/"'V":4~'#0
- c\b/#65535'"c\b/":5~'#0c\b/#65535'"'~'#0
- c\b/#65535'"
- 226 DO (1555) NEXT
- 227 (1554) PLEASE DO (1001) NEXT
- 228 (1555) DO FORGET #1
- 229 DO .5 <- "V\b-':4~#1'c\b/#2"~#3
- 230 DO (1551) NEXT
- 231 DO :2 <- ":2~'#0c\b/#65534'"c\b/":2~'#65535c\b/#0'"
- 232 DO :4 <- ":4~'#0c\b/#65534'"c\b/":4~'#65535c\b/#0'"
- 233 PLEASE DO (1556) NEXT
- 234 (1551) DO (1001) NEXT
- 235 PLEASE RETRIEVE :1 + :4 + :5 + .5
- 236 PLEASE RESUME #2
- 237 (1900) DO STASH .2 + .3 + .5
- 238 DO .1 <- #0
- 239 DO .2 <- #1
- 240 PLEASE DO (1901) NEXT
- 241 (1901) DO FORGET #1
- 242 DO %50 .1 <- 'V.1c\b/.2'~'#0c\b/#65535'
- 243 DO .2 <- !2c\b/#0'~'#32767c\b/#1'
- 244 PLEASE DO .5 <- "V\b-!2~.2'c\b/#1"~#3
- 245 DO (1902) NEXT
- 246 DO (1901) NEXT
- 247 (1902) DO (1001) NEXT
- 248 DO RETRIEVE .2 + .3 + .5
- 249 PLEASE RESUME #2
- 250 (1910) PLEASE STASH .1 + .3 + .5 + :1 + :2 + :3
- 251 DO .3 <- #65524
- 252 DO :1 <- #6
-
-
-
-
-
-
-
-
- - 46 -
-
-
-
- 253 DO (1911) NEXT
- * 254 PLEASE NOTE THAT YOU CAN'T GET THERE FROM HERE
- 255 (1912) DO (1001) NEXT
- 256 (1911) DO FORGET #1
- 257 PLEASE DO (1900) NEXT
- 258 DO :2 <- .1
- 259 DO (1500) NEXT
- 260 PLEASE DO :1 <- :3
- 261 DO .1 <- .3
- 262 DO (1020) NEXT
- 263 PLEASE DO .3 <- .1
- 264 DO .5 <- 'V\b-"!3~.3'~#1"c\b/#2'~#3
- 265 DO (1912) NEXT
- 266 DO .1 <- #12
- 267 PLEASE DO (1050) NEXT
- 268 DO RETRIEVE .1
- 269 DO (1530) NEXT
- 270 DO :2 <- #32768
- 271 DO (1500) NEXT
- 272 PLEASE DO .2 <- :3~'#65280c\b/#65280'
- 273 PLEASE RETRIEVE .3 + .5 + :1 + :2 + :3
- 274 DO RESUME #1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 47 -
-
-
-
- _\b8_\b._\b4 _\bP_\br_\bo_\bg_\br_\ba_\bm_\bm_\bi_\bn_\bg _\bS_\bu_\bg_\bg_\be_\bs_\bt_\bi_\bo_\bn_\bs
-
- For the novice INTERCAL programmer, we provide here a list
- of suggested INTERCAL programming projects:
-
- Write an integer exponentiation subroutine. :1 <- .1 raised
- to the .2 power.
-
- Write a double-precision sorting subroutine. Given 32-bit
- array ;1 of size :1, sort the contents into numerically
- increasing order, leaving the results in ;1.
-
- Generate a table of prime numbers.
-
- Put together a floating-point library, using 32-bit
- variables to represent floating-point numbers (let the upper
- half be the mantissa and the lower half be the
- characteristic). The library should be capable of
- performing floating-point addition, subtraction,
- multiplication, and division, as well as the natural
- logarithm function.
-
- Program a Fast Fourier Transform (FFT). This project would
- probably entail the writing of the floating-point library as
- well as sine and cosine functions.
-
- Calculate, to :1 places, the value of pi.
-
- (Working programs for each of these projects are included in
- the C-INTERCAL distribution's pit directory of sample code.)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 48 -
-
-
-
- _\b9_\b. _\bE_\bR_\bR_\bO_\bR _\bM_\bE_\bS_\bS_\bA_\bG_\bE_\bS
-
-
- Alice felt dreadfully puzzled. The Hatter's remark seemed to
- her to have no sort of meaning in it, and yet it was
- certainly English. "I don't quite understand you," she said,
- as politely as she could.
-
-
- Due to INTERCAL's implementation of comment lines (see
- section 4.5), most error messages are produced during
- execution instead of during compilation. All errors except
- those not causing immediate termination of program execution
- are treated as fatal.
-
- _\b9_\b._\b1 _\bF_\bo_\br_\bm_\ba_\bt
-
- All error messages appear in the following form:
-
- ICLnnnI (error message)
- ON THE WAY TO STATEMENT nnnn
- CORRECT SOURCE AND RESUBMIT
-
- The message varies depending upon the error involved. For
- undecodable statements the message is the statement itself.
- The second line tells which statement would have been
- executed next had the error not occurred. Note that if the
- error is due to 80 attempted levels of NEXTing, the
- statement which would have been executed next need not be
- anywhere near the statement causing the error.
-
- _\b9_\b._\b2 _\bM_\be_\bs_\bs_\ba_\bg_\be_\bs
-
- Brief descriptions of the different error types are listed
- below according to message number.
-
- 000 An undecodable statement has been encountered in the
- course of execution. Note that keypunching errors can
- be slightly disastrous, since if 'FORGET' were
- misspelled F-O-R-G-E-R, the results would probably not
- be those desired. Extreme misspellings may have even
- more surprising consequences. For example, misspelling
- 'FORGET' R-E-S-U-M-E could have drastic results.
-
- 017 An expression contains a syntax error.
-
- 079 Improper use has been made of statement identifiers.
-
- 099 Improper use has been made of statement identifiers.
-
- 123 Program has attempted 80 levels of NEXTing.
-
- 129 Program has attempted to transfer to a non-existent
- line label.
-
-
-
-
-
-
-
-
- - 49 -
-
-
-
- 139 An ABSTAIN or REINSTATE statement references a non-
- existent line label.
-
- 182 A line label has been multiply defined.
-
- 197 An invalid line label has been encountered.
-
- 200 An expression involves an unidentified variable.
-
- 240 An attempt has been made to give an array a dimension
- of zero.
-
- 241 Invalid dimensioning information was supplied in
- defining or using an array.
-
- 275 A 32-bit value has been assigned to a 16-bit variable.
-
- 436 A retrieval has been attempted for an unSTASHed value.
-
- 533 A WRITE IN statement or interleave (c\b/) operation has
- produced a value requiring over 32 bits to represent.
-
- 562 Insufficient data.
-
- 579 Input data is invalid.
-
- 621 The expression of a RESUME statement evaluated to #0.
-
- 632 Program execution was terminated via a RESUME statement
- instead of GIVE UP.
-
- 633 Execution has passed beyond the last statement of the
- program.
-
- 774 A compiler error has occurred (see section ).
-
- 778 An unexplainable compiler error has occurred.
-
- The following error codes are new in C-INTERCAL:
-
- 111 You tried to use a C-INTERCAL extension with the
- `traditional' flag on.
-
- 127 Can't find syslib.i file when it's needed for magical
- inclusion.
-
- 222 Out of stash space, or attempt to stash an undeclared
- array.
-
- 333 Too many variables.
-
- 444 A COME FROM statement references a non-existent line
- label.
-
-
-
-
-
-
-
-
-
- - 50 -
-
-
-
- 555 More than one COME FROM references the same label.
-
- 666 Too many source lines.
-
- 777 No such source file.
-
- 888 Can't open C output file.
-
- 999 Can't open C skeleton file.
-
- 998 Source file name with invalid extension (use .i or
- .[2-7]i).
-
- 997 Illegal possession of a controlled unary operator.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 51 -
-
-
-
- _\b1_\b0_\b. _\bT_\bh_\be _\bC_\b-_\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL _\bC_\bo_\bm_\bp_\bi_\bl_\be_\br
-
-
- "And yet it was a very clever pudding to invent."
-
- "What did you mean it to be made of?" Alice asked, hoping to
- cheer him up, for the poor Knight seemed quite low-spirited
- about it.
-
- "It began with blotting-paper," the Knight answered with a
- groan.
-
- "That wouldn't be very nice, I'm afraid --"
-
- "Not very nice _\ba_\bl_\bo_\bn_\be," he interrupted, quite eagerly, "but
- you've no idea what a difference it makes, mixing it with
- other things -- such as gunpowder and sealing-wax."
-
-
- This section describes the use of ick, the C-INTERCAL
- compiler. Information specific to the other known INTERCAL
- compilers appears in the following sections. These sections
- are less useful, since the other compilers are no longer
- available, but they are retained to provide a sense of
- history, and because any information regarding INTERCAL is
- really too scarce to discard.
-
- _\b1_\b0_\b._\b1 _\bC_\bh_\ba_\br_\ba_\bc_\bt_\be_\br _\bS_\be_\bt
-
- The C-INTERCAL compiler uses ASCII rather than EBCDIC. We
- follow the Atari implementation (see section ) by (a)
- replacing the change sign (c\b/) with big money ($) as the
- mingle operator, and (b) replacing the bookworm (V\b-) symbol
- with what (?) as the XOR operator.
-
- Version 0.18 and later versions accept the Latin-1 (ISO
- 8859-1) character set, which is a superset of ASCII. As a
- result, 0xA2 (c\b/), 0xA3 (quid), and 0xA4 (zlotnik) are
- accepted as mingle operators.
-
- Version 0.20 and later versions also accept UTF-8 as an
- alternative to Latin-1. The above three currency operators
- will be accepted in either Latin-1 or UTF-8 format. UTF-8
- format is required if you wish to use any of EURO-CURRENCY
- SIGN, COLON SIGN (that's Costa Rican dinero, not the
- Intercal two-spot), CRUZEIRO SIGN, FRENCH FRANC SIGN, LIRA
- SIGN, MILL SIGN, NAIRA SIGN, PESETA SIGN, RUPEE SIGN, WON
- SIGN, NEW SHEQEL SIGN, DONG SIGN, EURO SIGN, BENGALI RUPEE
- MARK, BENGALI RUPEE SIGN, or THAI CURRENCY SYMBOL BAHT.
- (Isn't internationalization wonderful?) Furthermore, you
- can use the Intercal character FOR ALL to represent the what
- operator.
-
-
-
-
-
-
-
-
-
-
- - 52 -
-
-
-
- _\b1_\b0_\b._\b2 _\bU_\bs_\ba_\bg_\be _\ba_\bn_\bd _\bC_\bo_\bm_\bp_\bi_\bl_\ba_\bt_\bi_\bo_\bn _\bO_\bp_\bt_\bi_\bo_\bn_\bs
-
- To compile an INTERCAL program `foo.i' to executable code,
- just do
-
- ick foo.i
-
- There's a -c option that leaves the generated C code in
- place for inspection (suppressing compilation to machine
- code), a -d option that enables verbose parse reporting from
- the yacc/bison parser, a -t option that requires strict
- INTERCAL-72 compliance (rejecting COME FROM and the
- extensions for bases other than two), a -b option that
- disables the INTERCAL-72 random-bug feature (error 774), and
- an -O option that enables the (hah!) optimizer. Invoking ick
- -? prints a usage message.
-
- Another compilation switch affects C-INTERCAL's runtime
- behavior. The `-C' option forces output in "clockface" mode,
- for superstitious users who believe writing "IV" upside-down
- offends IVPITER and would rather see IIII.
-
- _\b1_\b0_\b._\b3 _\bR_\bu_\bn_\bt_\bi_\bm_\be _\bO_\bp_\bt_\bi_\bo_\bn_\bs
-
- Every C-INTERCAL runtime also accepts certain options at
- runtime. These include [+/-]help, [+/-]traditional, and
- [+/-]wimpmode. The help option (with either + or -)
- triggers a 'usage' message. The +traditional option is
- presently a no-op.
-
- Steve explains: "The wimpmode option is the most
- interesting. I found myself always running my test programs
- with filters on both ends to work around the 'nifty'
- INTERCAL number representations. This was so painful that I
- decided it would be _\bl_\be_\bs_\bs painful (and a lot less code) if I
- added a 'wimp' option. With the +wimpmode option, the user
- is subjected to a humiliating message about what a wimp he
- or she is to use this mode, but after that is allowed to use
- conventional numerical notation. While such a mode doubtless
- violates to some extent the INTERCAL philosophy, the fact
- that an 'unbutcher' command has been posted clearly
- indicates the need for it. Anyway ... if you don't like it,
- don't use it ... the default is -wimpmode (i.e. _\bn_\bo_\bt wimp
- mode)."
-
- _\b1_\b0_\b._\b4 _\bP_\bL_\bE_\bA_\bS_\bE _\bP_\bo_\bl_\bi_\bt_\be_\bs_\bs_\be _\bC_\bh_\be_\bc_\bk_\bi_\bn_\bg
-
- A feature of INTERCAL-72 not documented in the original
- manual was that it required a certain level of politesse
- from the programmer. If fewer than 1/5th of the program
- statements included the PLEASE qualifier, the program would
- be rejected as insufficiently polite. If more than 1/3rd of
- them included PLEASE, the program would be rejected as
- excessively polite.
-
-
-
-
-
-
-
-
- - 53 -
-
-
-
- This check has been implemented in C-INTERCAL. To assist
- programmers in coping with it, the intercal.el mode included
- with the distribution randomly expands "do " in entered
- source to "PLEASE DO" 1/4th of the time.
-
- _\b1_\b0_\b._\b5 _\bL_\bo_\bc_\ba_\bl_\bi_\bz_\ba_\bt_\bi_\bo_\bn_\b: _\bA_\bn_\bc_\bi_\be_\bn_\bt _\bR_\bo_\bm_\ba_\bn
-
- Version 0.18 and later versions of C-Intercal have been
- localized for Ancient Roman as well as English-speaking
- locales. This means that Latin-language keywords are
- accepted as equivalents for the English-based ones
- traditionally used. See src/lexer.l for details, as we do
- not propose to break Priscian's head (publicly expose our
- ignorance of Latin) here.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 54 -
-
-
-
- _\b1_\b1_\b. _\bT_\bh_\be _\bA_\bt_\ba_\br_\bi _\bI_\bm_\bp_\bl_\be_\bm_\be_\bn_\bt_\ba_\bt_\bi_\bo_\bn
-
-
- "Perhaps it doesn't understand English," thought Alice. "I
- daresay it's a French mouse, come over with William the
- Conqueror." (For, with all her knowledge of history, Alice
- had no very clear notion how long ago anything had
- happened.)
-
-
- The Atari implementation of INTERCAL differs from the
- original Princeton version primarily in the use of ASCII
- rather than EBCDIC. Since there is no "change" sign (c\b/) in
- ASCII, we have substituted the "big money" ($) as the mingle
- operator. We feel that this correctly represents the
- increasing cost of software in relation to hardware.
- (Consider that in 1970 one could get RUNOFF for free, to run
- on a $20K machine, whereas today a not quite as powerful
- formatter costs $99 and runs on a $75 machine.) We also feel
- that there should be no defensible contention that INTERCAL
- has any sense. Also, since overpunches are difficult to
- read on the average VDT, the exclusive-or operator may be
- written ?. This correctly expresses the average person's
- reaction on first encountering exclusive-or, especially on a
- PDP-11. Note that in both of these cases, the over-punched
- symbol may also be used if one is masochistic, or concerned
- with portability to the Princeton compiler. The correct
- over-punch for "change" is "c<backspace>/" and the correct
- over-punch for V\b- is "V<backspace>-". These codes will be
- properly printed if you have a proper printer, and the
- corresponding EBCDIC code will be produced by the /IBM
- option on the LIST command.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 55 -
-
-
-
- _\b1_\b2_\b. _\bT_\bh_\be _\bP_\br_\bi_\bn_\bc_\be_\bt_\bo_\bn _\bC_\bo_\bm_\bp_\bi_\bl_\be_\br
-
-
- "My name is Alice, so please your Majesty," said Alice very
- politely; but she added, to herself, "Why, they're only a
- pack of cards, after all. I needn't be afraid of them!"
-
-
- The Princeton compiler, written in SPITBOL (a variant of
- SNOBOL), performs the compilation in two stages. First the
- INTERCAL source is converted into SPITBOL source, then the
- latter is compiled and executed.
-
- It should be noted that the Princeton compiler fails to
- properly interpret certain multiply-subscripted expressions,
- such as:
-
- ",1SUB",2SUB#1"#2"
-
-
- This is not a "bug". Being documented, it is merely a
- "restriction". Such cases may be resolved by alternating
- sparks and ears in various levels of expression nesting:
-
- ",1SUB',2SUB#1'#2"
-
- which is advisable in any case, since INTERCAL expressions
- are unreadable enough as is.
-
- Since there is currently no catalogued procedure for
- invoking the compiler, the user must include the in-line
- procedure shown in Figure 3 in his job before the
- compilation step. Copies of this in-line procedure may be
- obtained at any keypunch if the proper keys are struck.
-
- The compiler is then executed in the usual manner:
-
-
- // EXEC INTERCAL[,PARM='parameters']
- //COMPILE.SYSIN DD *
- {INTERCAL source deck}
- /*
- //EXECUTE.SYSWRITE DD *
- {input data}
- /*
-
-
- The various parameters are described following the in-line
- procedure. At most one parameter from each set may apply to
- a given compilation; if more than one are specified, the
- results are undefined, and may vary depending upon the
- particular set of options. The default parameters are
- underlined.
-
-
-
-
-
-
-
-
-
- - 56 -
-
-
-
- //INTERCAL PROC
- //COMPILE EXEC PGM=INTERCAL
- //STEPLIB DD DSN=U.INTERCAL.LIBRARY,DISP=SHR
- // DD DSN=SYS1.FORTLIB,DISP=SHR
- //SYSPRINT DD SYSOUT=A,DCB=(BLKSIZE=992,LRECL=137,RECFM=VBA)
- //SYSPUNCH DD DUMMY
- //SCRATCH DD DSN=&COMPSET,UNIT=SYSDA,SPACE=(CYL,(3,1)),DISP=(,PASS)
- //EXECUTE EXEC PGM=EXECUTE,COND=(4,LT)
- //SOURCES DD DSN=U.INTERCAL.SOURCES,DISP=SHR 4
- //STEPLIB DD DSN=U.INTERCAL.LIBRARY,DISP=SHR
- // DD DSN=SYS5.SPITLIB,DISP=SHR
- // DD DSN=SYS1.FORTLIB,DISP=SHR
- //SYSIN DD DSN=&COMPSET,DISP=(OLD,DELETE)
- //SYSOBJ DD SYSOUT=B,DCB=(BLKSIZE=80,LRECL=80,RECFM=F)
- //SYSPRINT DD SYSOUT=A,DCB=(BLKSIZE=992,LRECL=137,RECFM=VBA)
- //SYSPUNCH DD DUMMY
- // PEND
-
- Figure 3. Inline procedure for using INTERCAL.
-
- _\bO_\bP_\bT
- NOOPT
- In the default mode, the compiler will print a list of
- all options in effect, including the defaults for
- unspecified parameter groups and the effective option
- for those sets where one was specified. If NOOPT is
- requested, it causes the default mode to be assumed.
-
- _\bO_\bP_\bT_\bS_\bU_\bB
- NOOPTSUB
- NOSUB
- Unless 'NOOPTSUB' is requested, the System Library is
- optimized, resulting in much more rapid processing of
- function calls. Specifying NOOPTSUB causes the non-
- optimized INTERCAL code shown in section
- to be used, whereas NOSUB requests that the System
- Library be omitted altogether.
-
- IAMBIC
- _\bP_\bR_\bO_\bS_\bE
- The IAMBIC parameter permits the programmer to use
- poetic license and thus write in verse. If the reader
- does not believe it possible to write verse in
-
- ____________________
-
- 4. Pending acquisition of SPITBOL release 3.0, the SOURCES
- DD card must be replaced by the five cards:
-
- //NOOPTPFX DD DSN=U.INTERCAL.SOURCES(NOOPTPFX),DISP=SHR
- //NOOPTSUB DD DSN=U.INTERCAL.SOURCES(NOOPTSUB),DISP=SHR
- //OPTPFX DD DSN=U.INTERCAL.SOURCES(OPTPFX),DISP=SHR
- //OPTSUB DD DSN=U.INTERCAL.SOURCES(OPTSUB),DISP=SHR
- //PRELIM DD DSN=U.INTERCAL.SOURCES(PRELIM),DISP=SHR
-
-
-
-
-
-
-
-
- - 57 -
-
-
-
- INTERCAL, he should send the authors a stamped, self-
- addressed envelope, along with any INTERCAL program,
- and they will provide one which is verse.
-
- _\bF_\bO_\bR_\bM_\bA_\bT
- NOFORMAT
- In FORMAT mode, each statement printed is put on a
- separate line (or lines). In NOFORMAT mode, the free-
- format source is printed exactly as input. In this
- latter case, statement numbers are provided only for
- the first statement on a card, and they may be only
- approximate. Also, unrecognizable statements are not
- flagged.
-
- SEQ
- _\bN_\bO_\bS_\bE_\bQ
- If the source deck has sequence numbers in columns 73
- through 80, specifying 'SEQ' will cause them to be
- ignored.
-
- SOURCE
- _\bN_\bO_\bS_\bO_\bU_\bR_\bC_\bE
- If NOSOURCE is selected, all source listing is
- suppressed.
-
- LIST
- _\bN_\bO_\bL_\bI_\bS_\bT
- If LIST is specified, the compiler will provide a list
- of statement numbers catalogued according to type of
- statement. The compiler uses this table to perform
- abstentions by gerund.
-
- WIDTH=nn
- This sets the width (in number of characters) of the
- output line for FORMAT mode output. The default is 1\b13\b32\b2.\b.
-
- CODE
- _\bN_\bO_\bC_\bO_\bD_\bE
- Include 'CODE' in the parameter list to obtain a
- listing of the SPITBOL code produced for each INTERCAL
- statement.
-
- LINES=nn
- This determines the number of lines per page, during
- both compilation and execution. The default is 6\b60\b0.\b.
-
- DECK
- _\bN_\bO_\bD_\bE_\bC_\bK
- Selecting 'DECK' will cause the compiler to punch out a
- SPITBOL object deck which may then be run without
- reinvoking the INTERCAL (or SPITBOL) compiler.
-
- _\bK_\bI_\bD_\bD_\bI_\bN_\bG
-
-
-
-
-
-
-
-
-
- - 58 -
-
-
-
- NOKIDDING
- Select NOKIDDING to eliminate the snide remarks which
- ordinarily accompany INTERCAL error messages.
-
- _\bG_\bO
- NOGO
- Specifying 'NOGO' will cause the program to be
- compiled but not executed. EXECUTE/NOEXECUTE may be
- substituted for GO/NOGO, but this will result in an
- error, and GO will be assumed.
-
- _\bB_\bU_\bG
- NOBUG
- Under the default, there is a fixed probability of a
- fatal compiler bug being worked at random into the
- program being compiled. Encountering this bug during
- execution results in error message 774 (see section ).
- This probability is reduced to zero under 'NOBUG'. This
- does not affect the probability (presumably negligible)
- of error message 778.
-
- _\b1_\b2_\b._\b1 _\bO_\bt_\bh_\be_\br _\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL _\bC_\bo_\bm_\bp_\bi_\bl_\be_\br_\bs
-
- There are no other INTERCAL compilers. 5
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- ____________________
-
- 5. This assertion in the INTERCAL-72 manual was blatantly
- contradicted by some notes on an Atari implementation
- included at the end of the manual. So, you expect
- compiler manuals to be consistent?
-
-
-
-
-
-
-
- - 59 -
-
-
-
- T\bTO\bON\bNS\bSI\bIL\bL A\bA6\b6
-
-
-
-
-
-
-
-
- "Of course they answer to their names?" the Gnat remarked
- carelessly.
-
- "I never knew them to do it."
-
- "What's the use of their having names," the Gnat said, "if
- they wo'n't answer to them?"
- "No use to _\bt_\bh_\be_\bm," said Alice; "but it's useful to the people
- that name them, I suppose. If not, why do things have names
- at all?"
-
- "I ca'n't say," the Gnat replied. "Further on, in the wood
- down there, they've got no names -- however, go on with your
- list...."
-
-
- The Official INTERCAL Character Set
-
- Tabulated on page 59 are all the characters used in
- INTERCAL, excepting letters and digits, along with their
- names and interpretations. Also included are several
- characters not used in INTERCAL, which are presented for
- completeness and to allow for future expansion.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- ____________________
-
- 6. Since all other reference manuals have Appendices, it was
- decided that the INTERCAL manual should contain some
- other type of removable organ.
-
- 7. This footnote intentionally unreferenced.
-
-
-
-
- |
- |
- |
- | - 60 -
- |
- |
- |
- +\b.\bs\bi\b:\bt\bi\b,\bt\bi\b;\bh\bi\b#\bm\bi\b=\bh\b'\bs\bg\b`\bb\b!\bw\be\b?\bw\b_\bu\b"\br\bg\b"\b.\br\be\b|\bs\b%\bd\bp\b-\bw\bu\b<\ba\bu\b>\br\b(\bw\bp\b)\bw\bf\b[\bU\b]\bU\b{\be\b}\bb\b*\bs\bf\b&\ba\bu\bV\bV\bu\bV\b-\bb\bu\b$\bb\b_\bb\bc\b/\bc\bb\b~\bs\bb\b_\bf\b-\bo\bi\b+\bi\bs\b/\bs\b\\bb\b@\bw\b-\b'\bh\b^\bs\b#\b*\b[\bb\bb\ba\bn\bt\bs\bm\bi\b-\b'\bh\b0\bq\bb\b0\bz\bb-\bC\bN\bU\bp\bd\bw\bd\ba\bd\by\bd\be\bd\ba\bp\br\ba\bo\bq\bh\b_\bn\ba\br\ba\bq\bp\bo\be\bo\bs\bn\bs\bi\ba\br\ba\bo\bm\br\bp\bl\bm\bn\bn\bo\bn\bi\b_\bi\bh\bi\bq\bi\bl\bv\bn\bn\be\bl\ba\bh\bo\bh\b]\bl\bu\bn\bo\be\bw\bi\bn\ba\bx\bu\bi\bx\bl\bi-\bh\ba\bs\bo\be\bo\be\bi\be\bb\be\bs\be\bl\ba\bo\bc\bw\bu\ba\b_\ba\bb\bo\bb\bu\bi\bu\br\br\be\bg\be\bg\bx\be\bn\bl\bt\bt\bb\ba\bl\ba\bp\ba\b(\ba\bo\ba\bg\b_\bn\ba\bn\bi\bn\ba\be\bd\bt\bp\ba\bc\bi\bo\ba\bo\bn\bd\br\bx\ba\bc\bt\bl\bA\bi\bn\bA\bo\bn-\ba\bm\be\bt\bn\b-\bn\bl\bn\br\bn\bh\bn\bf\br\bu\bk\bi\bt\b_\br\bb\bu\bb\bi\bk\bb\bc\bm\bd\bl\bd\bh\bc\be\bl\bu\bu\br\bc\ba\bg\be\br\bo\br\bk\br\b_\ba\bn\ba\bg\ba\bt\br\bi\be\ba\bt\bk\br\bk\br\bt\bg\br\bw\bt\bs\br\be\bf\b3\bd\ba\b4\bt\ba-\br\be\bt\bs\bt\bt\bi\bt\bt\b-\bk\bp\bs\bv\b_\by\bi\bp\bi\bv\be\bl\be\be\bt\be\bo\br\br\ba\be\bt\bs\br\by\br\by\bw\by\bm\b_\br\bg\br\bg\br\bl\bc\br\br\bs\bl\bw\bk\bc\bh\be\be\bh\bo\br\br\bn\br-\ba\b(\bi\bp\bi\bi\bd\bi\bi\bm\be\bp\ba\bt\be\bt\ba\be\bn\bw\bw\bd\bw\bn\bn\bc\bl\bs\bo\bo\b_\by\be\by\bl\by\bw\bi\ba\bs\ba\bl\bp\bo\bh\bo\bw\bg\bg\bs\bw\bt\by\bi\by-\bc\bi\bf\bo\bf\bf\bf\bf\be\br\ba\bl\b_\be\b-\br\bl\b-\bt\bi\bi\ba\be\bs\be\be\bi\ba\bl\bb\bl\br\be\bn\be\bo\bn\bt\be\bt\ba\bo\br\b(\bl\bi\br\bc\bo\bu\bk-\bt\bf\by\bt\by\by\by\by\bs\br\be\b_\bx\be\be\bo\ba\bt\bt\bn\bs\bb\bt\bn\bn\bo\bo\bo\bm\bx\be\b_\bm\bm\bs\br\be\be\bc\be\bt\bo\bm\bo\be\bc\ba\ba\bo\br\br\bm\bm-\be\bh\bk\bn\b_\bl\ba\bn\bh\bg\bh\bh\bg\bl\ba\bv\bd\bg\bo\bg\bc\by\b_\bi\bi\be\bm\bs\bt\bs\bl\br\br\bn\bb\bp\bm\bn\bi\bi-\br\ba\b1\b3\b1\b3\bc\bt\b_\bu\br\bt\b-\be\bl\bl\bi\bc\ba\bi\bk\bi\b(\bl\b_\bn\bn\bl\bi\bn\bo\bb\be\bn\bn-\bn\b6\b2\b6\b2\bo\b_\bs\bs\bs\ba\bw\be\bi\bn\bk\bl\b8\bc\b)\bc\bo\bu\b_\bg\bg\be\b"\bo\bl\bs\ba\bs\bm\be\bg\bg-\by\b-\b-\b-\b-\bn\bt\b_\bi\bt\be\bq\bn\bo\bn\be\bi\ba\ba\br\bs\b_\bl\bl\bc\bt\bn\bi\bi\bm\bs\bi\br\bl\bl-\b)\bb\bb\bb\bb\bs\bo\b_\bv\bo\bv\bu\bg\br\be\bd\bl\bl\bi\b_\be\be\bt\bi\bs\bm\be\bn\be\be-\bi\bi\bi\bi\bt\b_\be\be\ba\bl\bm\bl\bu\bv\bm\bt\bp\bu-\bt\bt\bt\bt\ba\bs\be\bn\bl\be\bs\bl\ba\bs\bA\bO\bn\be\b_\b(\be\bl\bg\bs-\bn\bp\b_\bO\ba\bi\bs\ba\bb\bt\bN\bR\bi\b_\bA\bs\bi\by\br-\bv\bv\ba\ba\bt\ba\b_\bR\br\bf\bb\be\ba\bD\bv\bO\b_\bS\bt\ba-\ba\ba\br\br\br\bs\bi\be\bl\bt\be\bR\b_\bC\b1\be\bs\bb-\br\br\br\br\bk\b_\b(\b-\be\bl\be\br\b_\bI\b0\bm\bh\bb-\bi\bi\ba\ba\b-\b_\bA\bs\br\bm\bs\b_\bI\b0\bs\ba\be-\ba\ba\by\by\bs\b_\bS\bp\be\ba\b_\b)\b0\br\br-\bb\bb\bp\b_\bC\bo\bn\bl\b"\bk-\bl\bl\bo\b_\bI\bt\bt\bf-\be\be\bt\b_\bI\bs\bq\bi-\b_\b)\bu\bn-\ba\b)-\bl-\bi-\bf-\bi-\be-\br-\b)---------------------------------------------+
- |Character Name Use (if any) |
- |. spot identify 16-bit variable |
- |: two-spot identify 32-bit variable |
- |, tail identify 16-bit array |
- |; hybrid identify 32-bit array |
- |# mesh identify constant |
- |= half-mesh |
- |' spark grouper |
- |` backspark |
- |! wow equivalent to spark-spot |
- |? what unary logical XOR |
- |" rabbit-ears grouper |
- |"\b. rabbit equivalent to ears-spot |
- || spike |
- |% double-oh-seven percentage qualifier |
- |- worm used with angles |
- |< angle used with worms |
- |> right angle |
- |( wax precedes line label |
- |) wane follows line label |
- |[ U turn |
- |] U turn back |
- |{ embrace |
- |} bracelet |
- |* splat flags invalid statements |
- |& ampersand 10 unary logical AND |
- |V V (or book) unary logical OR |
- |V\b- bookworm (universal qualifier) unary logical XOR (INTERCAL-72) |
- |$ big money binary mingle |
- |c\b/ change binary mingle (INTERCAL-72) |
- |~ sqiggle binary select |
- |_ flat worm |
- |- overline indicates "times 1000" |
- |+ intersection separates list items |
- |/ slat |
- |\ backslat |
- |@ whirlpool unary logical BUT (TriINTERCAL) |
- |-\b' hookworm |
- |^ shark (or simply sharkfin) unary logical XOR (TriINTERCAL) |
- |#\b*\b[] blotch |
- | bunghole |
- | name grabber |
- | andrew cross |
- | norwegian minus |
- | text grabber |
- | swash |
- | microscope |
- | interworm |
- |-\b' half turn |
- |0xA3 quid binary mingle |
- |0xA4 zlotnik binary mingle |
- | |
- +--------\bT-\ba-\bb-\bl-\be--\b2--\b(-\bt-\bo-\bp--\bv-\bi-\be-\bw-\b)-\b.--\bI-\bN-\bT-\bE-\bR-\bC-\bA-\bL--\bc-\bh-\ba-\br-\ba-\bc-\bt-\be-\br--\bs-\be-\bt-\b.---------------------------+
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- ____________________
-
- 10.Got any better ideas?
-
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+++ /dev/null
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- T\bTH\bHE\bE I\bIN\bNT\bTE\bER\bRC\bCA\bAL\bL P\bPR\bRO\bOG\bGR\bRA\bAM\bMM\bMI\bIN\bNG\bG L\bLA\bAN\bNG\bGU\bUA\bAG\bGE\bE
-
- _\bD_\bo_\bn_\ba_\bl_\bd _\bR_\b. _\bW_\bo_\bo_\bd_\bs
- _\ba_\bn_\bd
- _\bJ_\ba_\bm_\be_\bs _\bM_\b. _\bL_\by_\bo_\bn
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- _\b1_\b. _\bI_\bN_\bT_\bR_\bO_\bD_\bU_\bC_\bT_\bI_\bO_\bN
-
- The names you are about to ignore are true. However, the
- story has been changed significantly. Any resemblance of the
- programming language portrayed here to other programming
- languages, living or dead, is purely coincidental.
-
- _\b1_\b._\b1 _\bO_\br_\bi_\bg_\bi_\bn _\ba_\bn_\bd _\bP_\bu_\br_\bp_\bo_\bs_\be
-
- The INTERCAL programming language was designed the morning
- of May 26, 1972 by Donald R. Woods and James M. Lyon, at
- Princeton University. Exactly when in the morning will
- become apparent in the course of this manual. It was
- inspired by one ambition: to have a compiler language which
- has nothing at all in common with any other major language.
- By 'major' was meant anything with which the authors were at
- all familiar, e.g., FORTRAN, BASIC, COBOL, ALGOL, SNOBOL,
- SPITBOL, FOCAL, SOLVE, TEACH, APL, LISP, and PL/I. For the
- most part, INTERCAL has remained true to this goal, sharing
- only the basic elements such as variables, arrays, and the
- ability to do I/O, and eschewing all conventional operations
- other than the assignment statement (FORTRAN "=").
-
- _\b1_\b._\b2 _\bA_\bc_\br_\bo_\bn_\by_\bm
-
- The full name of the compiler is "Compiler Language With No
- Pronounceable Acronym", which is, for obvious reasons,
- abbreviated "INTERCAL".
-
- _\b1_\b._\b3 _\bA_\bc_\bk_\bn_\bo_\bw_\bl_\be_\bd_\bg_\bm_\be_\bn_\bt_\bs
-
- The authors are deeply indebted to Eric M. Van and Daniel J.
- Warmenhoven, without whose unwitting assistance this manual
- would still have been possible.
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- _\b2_\b. _\bF_\bU_\bN_\bD_\bA_\bM_\bE_\bN_\bT_\bA_\bL _\bC_\bO_\bN_\bC_\bE_\bP_\bT_\bS
-
- In this section an attempt is made to describe how and why
- INTERCAL may be used; i.e., what it is like and what it is
- good for.
-
- _\b2_\b._\b1 _\bS_\ba_\bm_\bp_\bl_\be _\bP_\br_\bo_\bg_\br_\ba_\bm
-
- Shown below is a relatively simple INTERCAL program which
- will read in 32-bit unsigned integers, treat them as signed,
- 2's-complement numbers, and print out their absolute values.
- The program exits if the absolute value is zero. Note in
- particular the inversion routine (statements 6 through 14),
- which could be greatly simplified if the subroutine library
- (see section ) were used.
-
- A more detailed analysis of a program is made in section
- of this manual.
-
-
- DO (5) NEXT
- (5) DO FORGET #1
- PLEASE WRITE IN :1
- DO .1 <- 'V\b-":1~'#32768c\b/#0'"c\b/#1'~#3
- DO (1) NEXT
- DO :1 <- "'V\b-":1~'#65535c\b/#0'"c\b/#65535'
- ~'#0c\b/#65535'"c\b/"'V\b-":1~'#0c\b/#65535'"
- c\b/#65535'~'#0c\b/#65535'"
- DO :2 <- #1
- PLEASE DO (4) NEXT
- (4) DO FORGET #1
- DO .1 <- "V\b-':1~:2'c\b/#1"~#3
- DO :1 <- "'V\b-":1~'#65535c\b/#0'"c\b/":2~'#65535
- c\b/#0'"'~'#0c\b/#65535'"c\b/"'V\b-":1~'#0
- c\b/#65535'"c\b/":2~'#0c\b/#65535'"'~'#0c\b/#65535'"
- DO (1) NEXT
- DO :2 <- ":2~'#0c\b/#65535'"
- c\b/"'":2~'#65535c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- DO (4) NEXT
- (2) DO RESUME .1
- (1) PLEASE DO (2) NEXT
- PLEASE FORGET #1
- DO READ OUT :1
- PLEASE DO .1 <- 'V\b-"':1~:1'~#1"c\b/#1'~#3
- DO (3) NEXT
- PLEASE DO (5) NEXT
- (3) DO (2) NEXT
- PLEASE GIVE UP
-
-
- _\b2_\b._\b2 _\bU_\bs_\be_\bs _\bf_\bo_\br _\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL
-
- INTERCAL's main advantage over other programming languages
- is its strict simplicity. It has few capabilities, and thus
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- there are few restrictions to be kept in mind. Since it is
- an exceedingly easy language to learn, one might expect it
- would be a good language for initiating novice programmers.
- Perhaps surprising, then, is the fact that it would be more
- likely to initiate a novice into a search for another line
- of work. As it turns out, INTERCAL is more useful (which
- isn't saying much) as a challenge to professional
- programmers. Those who doubt this need only refer back to
- the sample program in section . This 23-statement program
- took somewhere from 15 to 30 minutes to write, whereas the
- same objectives can be achieved by single-statement programs
- in either SNOBOL;
-
- PLEASE INPUT POS(0) ('-' ! '')
- + (SPAN('0123456789') $ OUTPUT)
- + *NE(OUTPUT) :S(PLEASE)F(END)
-
- or APL;
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- [1] ->0!=[]<-|[]
-
- Admittedly, neither of these is likely to appear more
- intelligible to anyone unfamiliar with the languages
- involved, but they took roughly 60 seconds and 15 seconds,
- respectively, to write. Such is the overwhelming power of
- INTERCAL!
-
- The other major importance of INTERCAL lies in its seemingly
- inexhaustible capacity for amazing one's fellow programmers,
- confounding programming shop managers, winning friends, and
- influencing people. It is a well-known and oft-demonstrated
- fact that a person whose work is incomprehensible is held in
- high esteem. For example, if one were to state that the
- simplest way to store a value of 65536 in a 32-bit INTERCAL
- variable is:
-
- DO :1 <- #0c\b/#256
-
- any sensible programmer would say that that was absurd.
- Since this is indeed the simplest method, the programmer
- would be made to look foolish in front of his boss, who
- would of course happened to turn up, as bosses are wont to
- do. The effect would be no less devastating for the
- programmer having been correct.
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- _\b3_\b. _\bD_\bE_\bS_\bC_\bR_\bI_\bP_\bT_\bI_\bO_\bN
-
- The examples of INTERCAL programming which have appeared in
- the preceding sections of this manual have probably seemed
- highly esoteric to the reader unfamiliar with the language.
- With the aim of making them more so, we present here a
- description of INTERCAL.
-
- _\b3_\b._\b1 _\bV_\ba_\br_\bi_\ba_\bb_\bl_\be_\bs
-
- INTERCAL allows only 2 different types of variables, the
- 1\b16\b6-\b-b\bbi\bit\bt i\bin\bnt\bte\beg\bge\ber\br and the 3\b32\b2-\b-b\bbi\bit\bt i\bin\bnt\bte\beg\bge\ber\br.\b. These are
- represented by a spot (.) or two-spot (:), respectively,
- followed by any number between 1 and 65535, inclusive.
- These variables may contain only non-negative numbers; thus
- they have the respective ranges of values: 0 to 65535 and 0
- to 4294967295. Note: .123 and :123 are two distinct
- variables. On the other hand, .1 and .0001 are identical.
- Furthermore, the latter may _\bn_\bo_\bt be written as 1E-3.
-
- _\b3_\b._\b2 _\bC_\bo_\bn_\bs_\bt_\ba_\bn_\bt_\bs
-
- C\bCo\bon\bns\bst\bta\ban\bnt\bts\bs are 16-bit values only and may range from 0 to
- 65535. They are prefixed by a mesh (#). Caution! Under no
- circumstances confuse the mesh with the interleave operator,
- except under confusing circumstances!
-
- _\b3_\b._\b3 _\bA_\br_\br_\ba_\by_\bs
-
- A\bAr\brr\bra\bay\bys\bs are represented by a tail (,) for 16-bit values, or a
- hybrid (;) for 32-bit values, followed by a number between 1
- and 65535, inclusive. The number is suffixed by the word
- SUB, followed by the subscripts, separated optionally by
- spaces. Subscripts may be any expressions, including those
- involving subscripted variables. This occasionally leads to
- ambiguous constructions, which are resolved as discussed in
- section . Definition of array dimensions will be discussed
- later in greater detail, since discussing it in less detail
- would be difficult. As before, ,123 and ;123 are distinct.
- In summary, .123, :123, #123, ,123, and ;123 are all
- distinct.
-
- _\b3_\b._\b4 _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- INTERCAL recognizes 5 operators -- 2 binary and 3 unary 1.
- Please be kind to our operators: they may not be very
- intelligent, but they're all we've got. In a sense, all 5
- operators are binary, as they are all bit-oriented, but it
- is not our purpose here to quibble about bits of trivia.
-
- _\b3_\b._\b4_\b._\b1 _\bB_\bi_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- The binary operators are i\bin\bnt\bte\ber\brl\ble\bea\bav\bve\be (also called m\bmi\bin\bng\bgl\ble\be) and
- s\bse\bel\ble\bec\bct\bt, which are represented by a change (c\b/) and a sqiggle
-
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- [sic] (~), respectively.
-
- The interleave operator takes two 16-bit values and produces
- a 32-bit result by alternating the bits of the operands.
- Thus, #65535c\b/#0 has the 32-bit binary form 101010....10 or
- 2863311530 decimal, while #0c\b/#65535 = 0101....01 binary =
- 1431655765 decimal, and #255c\b/#255 is equivalent to #65535.
-
- The select operator takes from the first operand whichever
- bits correspond to 1's in the second operand, and packs
- these bits to the right in the result. Both operands are
- automatically padded on the left with zeros to 32 bits
- before the selection takes place, so the variable types are
- unrestricted. If more than 16 bits are selected, the result
- is a 32-bit value, otherwise it is a 16-bit value. For
- example, #179~#201 (binary value 10110011~11001001) selects
- from the first argument the 8th, 7th, 4th, and 1st from last
- bits, namely, 1001, which = 9. But #201~#179 selects from
- binary 11001001 the 8th, 6th, 5th, 2nd, and 1st from last
- bits, giving 10001 = 17. #179~#179 has the value 31, while
- #201~#201 has the value 15.
-
- Perhaps a simpler way of understanding the operation of the
- select operator would be to examine the logic diagram in
- Figure 1, which performs the select operation upon two 8-bit
- values, A and B. The gates used are Warmenhovian logic
- gates, which means the outputs have four possible values:
- low, high, undefined (value of an uninitialized flip-flop),
- and oscillating (output of a NOR gate with one input low and
- the other input connected to the output). These values are
- represented symbolically by '0', '1', '?', and 'O\b|'. Note in
- particular that, while NOT-0 is 1 and NOT-1 is 0 as in two-
- valued logic, NOT-? is ? and NOT-O\b| is O\b|. The functions of
- the various gates are listed in Table 1.
-
- [Warning: The following picture will be garbled or missing.
- Get a better output device.]
-
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- --+-+---- --+---- +--+---- --+---- +--+----
- A\b1 | | 1 +-+--+-+ 2 +-++-+ 3 ++-+-+ 3 ++|--+ 1 +--
- B --+++ | |--+-+ | || | ||||++ |||| | | TO
- 1 +++------++-+-+------+|-+--- +++++-----++|-+--- ---\bNEW
- +-------++-+---------+-------+++++-----+ | YORK
- +-+------++-+-+-----+ | +---- ||| +-----+ | +---- TO
- A\b2 --+-+ | || +-+ || --+ |+++-+ |+-+-+ | ---\bNEW
- --+-+ 1 +-++-+-+ 2 +++--+ 7 +-++-+ 3 +--+-+ 2 +-- YO\bTR\bOK
- B\b2 |-+--- |||+-+--- || -+--- |+-+------++-+------- ---\bNEW
- +--------+++-+------++---------+--------+|+--------- YORK
- +-+------+++-++-----++--+-----+| ++-----++--+-----+ TO
- A --+-+ | +++-++ |++--+ |++-++ ||+--+ || B ---\bNEW
- 3 | 1 +-+++-+| 2 +-++-+ 3 +-++++ 3 ++++-+ 3 ++- YORK
- B\b3 --+-+--- ||||+++--- |||-+--- ++|++--- ||+++--- | TO
- +-------++++++------+++-------++++------++++------+-U ---\bNEW
- +-+-----+++-+++-----+++-+-----+++|| ++++| | YORK
- A --+-+----|||| ||+----||++-+----||++++----|+++++----|| S TO
- 4 | 1 +++++|++ 2 ++++-+ 7 ++++++ 3 ++++-+ 4 ++- ---\bNEW
- B --+-+--- ||||+-+--- ||+-+--- |||++--- ++--++--- | YO\bTR\bOK
- 4 | |||+++ ++--+ +---++++++++++|+-+------+ ---\bNEW
- +-------+++-++-------++++-+--+||+++++++-++++--+ YORK
- --+-+-----+++-+++-----+++++-+--+++-++++++ +++++-+-- L TO
- A\b5 | 1 ++++++++ 2 ++++++ 3 +++ ++ 3 +-++++ 5 +-- ---\bNEW
- B --+-+ |||+++++ | ||| ||| || |++++| | YORK
- 5 |-+--- |||||++-------|++----+|+--+-----+++++-------I TO
- +-------+++++--------++------++++ +--- |+++ ---\bNEW
- +-+-----+++++-+-----+|| +----++++++-----+|||+---- N YORK
- A\b6 --+-+ |||-++++ |+++-+ |+++++ | ++++ | TO
- --+-+ 1 +++-++++ 2 ++++-+ 3 +-++++ 4 ++++++ 4 +-- ---\bNEW
- B\b6 |-+--- +++++++--- +++-+-----+||++-----+++++-------E YORK
- +--------++++--------++------+||| ++-+ ---TO
- +-+------++++-+-----+|| +----++++++---- || +---- NEW
- A --+-+ | -+++-+ |+++-+ |+++++ ||+--+ | YO\bTR\bOK
- 7 | 1 +--+|+-+ 2 +-++-+ 3 ++|+++ 4 ++-+-+ 5 +-- ---\bNEW
- B\b7 --+-+--- ||++-+--- ||++--- || ++--- --+++--- YORK
- +----+---++++--------+++------++ +------+-++------+- TO
- +-+--+---++++-+-------+|| | || | || | ---\bNEW
- A --+-+----| |+++-+----|+-+++----|+--++----||+--+----|| YORK
- 8 | 1 +-+ |+-+ 2 ++ +++ 4 ++ +++ 3 ++++-+ 5 ++-8 TO
- B --+-+--- +--+--- | ++--- | |++--- | |-+--- | ---\bNEW
- 8 +----------------+ ++-+ +-++---+ ++-+------+| YORK
- +--+++--------+|| +-++++------++- TO
- +---- +-+--+-----+++-+---- ++++----+|++-+----++- ---\bNEW
- | 6 +-+ +--+ 2 ++-+-+ 7 +-++-+ 3 +++|++ 4 ++- YO\bTR\bOK
- | | -+--+ |+---+ | | | || ||| || --\bP-\bHILA-
- -+--- | -+--- -+--- |-+--- +-+++--- | DELPHIA
- +---------------------+---------+-------+-
- +---- |+--+---------+------++-+-----+ +----
- | | ++--+ | +-+ | |--+ ||+--+ |
- | 6 +--++--+ 1 +-++-+ 1 +-+--+ 1 +++--+ 1 ++
- -+--- -+--- --++-+--- | -+--- | -+-----+-
- --- ---
- FIGURE 1. CIRCUITOUS DIAGRAM
-
-
-
-
-
-
-
-
-
- - 8 -
-
-
-
- __________________________________________________________
- |\ \
- | \ 1. Logic gate. Inputs A, B. Output O = AB. \
- | \ \
- | \ \ 2. Logic gate. Inputs A, B, C. Output O = A+BC. \
- | |\ \ \
- | | \ \ 3. Logic gate. Inputs A, B. Output O = A+AB. \
- | | \ \ \
- | | |\ \ 4. Logic gate. Inputs A, B. Output O = AB O\b+ -(A+-B) \
- | | | \ \ \
- | | | \ \ 5. Logic gate. Inputs A, B. Output O = AO\b+A + AA \
- | | | \ \ \
- | | | \ \ 6. Uninitialized flip-flop. Inputs none. Output O = ? \
- | | | \ \ \
- | | | \ \ 7. Flip-flop-flap. Inputs A, B, C. Output O = 1 if \
- | | | \ \ A=0 or B+C=0 and A=1. O = 0 if AC=1, B=0. O = O\b| if \
- | | | \ \ AB=1, C=0. O = ? if ABC=1. O as yet undetermined \
- | | | \ \ for other Warmenhovian inputs. See Figure 2. \
- | | | \ \ \
- | | | \ \ 8. Bus line. \
- | | | \ \_________________________________________________________\
- | | | \ | |
- | | | | | _____________________________________________________ |
- | | | | | | | | | | | |
- | | | | | | | | | | | |
- | | | | | | | | | | | |
- | | | | | | | | | | | |
- | | | | | | | | | | | |
- \|__| | | | \|__| | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
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- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- | | | | | |
- \|__| \|__|
-
- Table 1. Logical (and other) functions.
-
-
-
-
-
-
-
-
-
-
-
-
- - 9 -
-
-
-
- [Warning: The following picture will be garbled or missing.
- Get a better output device.]
-
-
-
-
-
-
-
-
-
-
- -------------------------+----
- A +---+ |----+------------D
- | | | |
- +----
-
-
-
- | | |
- +---+---- |
- B-------------------------+ |----+ |
- +----| | |
- | |
- | |
- | |
- | |
- | | |
- C-------------------------+----| | |
- +----------------+ |--+ | |
- | +---- | | |
- | | | |
- | |
- | |
- | |
- | | | | |
- | | +-+----| |
- | +---+ +- +-------+
- | +-+--
- 1-----+
-
-
-
-
-
-
-
-
-
-
- FIGURE 2. FLIP FLAP FLOP
-
-
-
-
-
-
-
-
-
-
-
- - 10 -
-
-
-
- [Warning: The following picture will be garbled or missing.
- Get a better output device.]
-
- -----
- ----- -----
- -----
- ----- -----
-
- ----- -----
- -----
- ----- -----
- ----- GATE TYPE 9. BLACK BOX
- ----- 9 ----- INPUTS A1-8, B1-8.
- ----- OUTPUT O1-8 = A1-8~B1-8
- ----- -----
- -----
- ----- -----
-
- ----- -----
- -----
- ----- -----
- -----
-
-
-
-
-
-
-
-
-
-
-
- FIGURE 1 (CONTINUED). NEW YORK
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 11 -
-
-
-
- _\b3_\b._\b4_\b._\b2 _\bU_\bn_\ba_\br_\by _\bO_\bp_\be_\br_\ba_\bt_\bo_\br_\bs
-
- The unary operators are & (logical A\bAN\bND\bD), V (logical O\bOR\bR), and
- V\b- (logical X\bXO\bOR\bR). This last character is obtained by
- overpunching a worm (-) on a V (V). The operator is
- inserted between the spot, two-spot, mesh, or what-have-you,
- and the integer, thus: .&123, #V\b-123. Multiple unary
- operators may not be concatenated, thus the form #V\b-&123 is
- invalid. This will be covered later when precedence is
- discussed. These operators perform their respective logical
- operations on all pairs of adjacent bits, the result from
- the first and last bits going into the first bit of the
- result. The effect is that of rotating the operand one
- place to the right and ANDing, ORing, or XORing with its
- initial value. Thus, #&77 (binary = 1001101) is binary
- 0000000000000100 = 4, #V77 is binary 1000000001101111 =
- 32879, and #V\b-77 is binary 1000000001101011 = 32875.
-
- _\b3_\b._\b4_\b._\b3 _\bP_\br_\be_\bc_\be_\bd_\be_\bn_\bc_\be
-
- Precedence of operators is as follows:
-
-
-
-
-
-
-
-
-
-
- (The remainder of this page intentionally left blank)2
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- ____________________
-
- 2. Keep in mind that the aim in designing INTERCAL was to
- have no precedents.
-
-
-
-
-
-
-
- - 12 -
-
-
-
- This precedence (or lack thereof) may be overruled by
- grouping expressions between pairs of sparks (') or rabbit-
- ears ("). Thus '#165c\b/#203'~#358 (binary value
- '10100101c\b/11001011'~101100110) has the value 15, but
- #165c\b/'#203~#358' has the value 34915, and #165c\b/#203~#358 is
- invalid syntax and is completely valueless (except perhaps
- as an educational tool to the programmer). A unary operator
- is applied to a sparked or rabbit-eared expression by
- inserting the operator immediately following the opening
- spark or ears. Thus, the invalid expression #V\b-&123, which
- was described earlier, could be coded as 'V\b-#&123' or
- 'V\b-"{"'. Note: In the interests of simplifying the
- sometimes overly-complex form of expressions, INTERCAL
- allows a spark-spot combination ('.) to be replaced with a
- wow (!). Thus '.1~.2' is equivalent to !1~.2', and 'V.1c\b/.2'
- is equivalent to "V!1c\b/.2'".
-
- Combining a rabbit-ears with a spot to form a rabbit ("\b.) is
- not permitted, although the programmer is free to use it
- should he find an EBCDIC reader which will properly
- translate a 12-3-7-8 punch.
-
- Sparks and/or rabbit-ears must also be used to distinguish
- among such otherwise ambiguous subscripted and multiply-
- subscripted expressions as:
-
- ,1 SUB #1 ~ #2
- ,1 SUB ,2 SUB #1 #2 #3
- ,1 SUB " ,2 SUB " ,3 SUB #1 " #2 " " #3 "
-
- The third case may be isolated into either of its possible
- interpretations by simply changing some pairs of rabbit-ears
- to sparks, instead of adding more ears (which would only
- confuse the issue further). Ambiguous cases are defined as
- those for which the compiler being used finds a legitimate
- interpretation which is different from that which the user
- had in mind. See also section .
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 13 -
-
-
-
- _\b4_\b. _\bS_\bT_\bA_\bT_\bE_\bM_\bE_\bN_\bT_\bS
-
- In this section is described the format of INTERCAL
- statements.
-
- _\b4_\b._\b1 _\bG_\be_\bn_\be_\br_\ba_\bl _\bF_\bo_\br_\bm_\ba_\bt
-
- Statements may be entered in 'free format'. That is, more
- than one statement may occur on a single card, and a
- statement may begin on one card and end on a later one. Note
- that if this is done, all intervening cards and portions
- thereof must be part of the same statement. That this
- restriction is necessary is immediately apparent from the
- following example of what might occur if statements could be
- interlaced.
-
- DO .1 <- ".1c\b/'&:51~"#V\b-1c!12~;&75SUB"V\b-'V.1~
- DO .2 <- '"!1c\b/"&';V\b-79SUB",&7SUB:173"'~!V\b-9c\b/
- .2'c\b/,&1SUB:5~#33578"'"'"~'#65535c\b/"V\b-'V#&85'"'
- #8196'"'~.1"c\b/.2'~'#&5c\b/"'#1279c\b/#4351'~#65535"'
-
- The above statements are obviously meaningless. (For that
- matter, so are the statements
-
- DO .1 <- ".1c\b/"&:51~"#V\b-1c\b/!12~;&75SUB"V\b-'V.1~
- .2'c\b/,&1SUB:5~#333578"'"'"~#65535c\b/"V\b-'V#&85'"'
- DO .2 <- '"!1c\b/"&';V\b-79SUB",&7SUB:173"'~!V\b-9c\b/
- #8196'"'~.1"c\b/.2'~'#&5c\b/"'#1279c\b/#4351'~#65535"'
-
- but this is not of interest here.)
-
- Spaces may be used freely to enhance program legibility (or
- at least reduce program illegibility), with the restriction
- that no word of a statement identifier (see section ) may
- contain any spaces.
-
- _\b4_\b._\b2 _\bL_\ba_\bb_\be_\bl_\bs
-
- A statement may begin with a l\blo\bog\bgi\bic\bca\bal\bl l\bli\bin\bne\be l\bla\bab\bbe\bel\bl enclosed in
- wax-wane pairs (()). A statement may not have more than one
- label, although it is possible to omit the label entirely. A
- line label is any integer from 1 to 65535, which must be
- unique within each program. The user is cautioned, however,
- that many line labels between 1000 and 1999 are used in the
- INTERCAL System Library functions.
-
- _\b4_\b._\b3 _\bI_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br_\bs _\ba_\bn_\bd _\bQ_\bu_\ba_\bl_\bi_\bf_\bi_\be_\br_\bs
-
- After the line label (if any), must follow one of the
- following statement identifiers: DO, PLEASE, or PLEASE DO.
- These may be used interchangeably to improve the aesthetics
- of the program. The identifier is then followed by either,
- neither, or both of the following optional parameters
- (qualifiers): (1) either of the character strings NOT or
-
-
-
-
-
-
-
-
- - 14 -
-
-
-
- N'T, which causes the statement to be automatically
- abstained from (see section ) when execution begins, and (2)
- a number between 0 and 100, preceded by a double-oh-seven
- (%), which causes the statement to have only the specified
- percent chance of being executed each time it is encountered
- in the course of execution.
-
- _\b4_\b._\b4 _\bS_\bt_\ba_\bt_\be_\bm_\be_\bn_\bt_\bs
-
- Following the qualifiers (or, if none are used, the
- identifier) must occur one of the 13 valid operations.
- (Exception: see section .) These are described individually
- in sections
- through .
-
- _\b4_\b._\b4_\b._\b1 _\bC_\ba_\bl_\bc_\bu_\bl_\ba_\bt_\be
-
- The INTERCAL equivalent of the half-mesh (=) in FORTRAN,
- BASIC, PL/I, and others, is represented by an angle (<)
- followed by a worm (-). This combination is read 'gets'.
- 32-bit variables may be assigned 16-bit values, which are
- padded on the left with 16 zero bits. 16-bit variables may
- be assigned 32-bit values only if the value is less than
- 65535. Thus, to invert the least significant bit of the
- first element of 16-bit 2-dimensional array number 1, one
- could write:
-
- ,1SUB#1#1 <- 'V\b-",1SUB#1#1"c\b/#1'~'#0c\b/#65535'
-
- Similarly to SNOBOL and SPITBOL, INTERCAL uses the angle-
- worm to define the dimensions of arrays. An example will
- probably best describe the format. To define 32-bit array
- number 7 as 3-dimensional, the first dimension being seven,
- the second being the current value of 16-bit variable number
- seven, and the third being the current value of the seventh
- element of 16-bit array number seven (which is one-
- dimensional) mingled with the last three bits of 32-bit
- variable number seven, one would write (just before they
- came to take him away):
-
- ;7 <- #7 BY .7 BY ",7SUB#7"c\b/':7~#7'
-
- This is, of course, different from the statement:
-
- ;7 <- #7 BY .7 BY ,7SUB"#7c\b/':7~#7'"
-
- INTERCAL also permits the redefining of array dimensioning,
- which is done the same way as is the initial dimensioning.
- All values of items in an array are lost upon
- redimensioning, unless they have been STASHed (see section
- ), in which case restoring them also restores the old
- dimensions.
-
-
-
-
-
-
-
-
-
-
- - 15 -
-
-
-
- _\b4_\b._\b4_\b._\b2 _\bN_\bE_\bX_\bT
-
- The NEXT statement is used both for subroutine calls and for
- unconditional transfers. This statement takes the form:
-
- DO (label) NEXT
-
- (or, of course,
-
- PLEASE DO (label) NEXT
-
- etc.), where (label) represents any logical line label which
- appears in the program. The effect of such a statement is to
- transfer control to the statement specified, and to store in
- a push down list (which is initially empty) the location
- from which the transfer takes place. Items may be removed
- from this list and may be discarded or used to return to the
- statement immediately following the NEXT statement. These
- operations are described in sections
- and
- respectively. The programmer is generally advised to
- discard any stack entries which he does not intend to
- utilize, since the stack has a maximum depth of 79 entries.
- A program's attempting to initiate an 80th level of NEXTing
- will result in the fatal error message, "PROGRAM HAS
- DISAPPEARED INTO THE BLACK LAGOON."
-
- _\b4_\b._\b4_\b._\b3 _\bF_\bO_\bR_\bG_\bE_\bT
-
- The statement PLEASE FORGET exp, where exp represents any
- expression (except colloquial and facial expressions),
- causes the expression to be evaluated, and the specified
- number of entries to be removed from the NEXTing stack and
- discarded. An attempt to FORGET more levels of NEXTing than
- are currently stacked will cause the stack to be emptied,
- and no error condition is indicated. This is because the
- condition is not considered to be an error. As described in
- section , it is good programming practice to execute a DO
- FORGET #1 after using a NEXT statement as an unconditional
- transfer, so that the stack does not get cluttered up with
- unused entries:
-
- DO (123) NEXT
- .
- .
- (123) DO FORGET #1
-
-
- _\b4_\b._\b4_\b._\b4 _\bR_\bE_\bS_\bU_\bM_\bE
-
- The statement PLEASE RESUME exp has the same effect as
- FORGET, except that program control is returned to the
- statement immediately following the NEXT statement which
- stored in the stack the last entry to be removed. Note that
-
-
-
-
-
-
-
-
- - 16 -
-
-
-
- a rough equivalent of the FORTRAN computed GO TO and BASIC
- ON exp GO TO is performed by a sequence of the form:
-
- DO (1) NEXT
- .
- .
- (1) DO (2) NEXT
- PLEASE FORGET #1
- .
- .
- (2) DO RESUME .1
-
- Unlike the FORGET statement, an attempt to RESUME more
- levels of NEXTing than has been stacked will cause program
- termination. See also section .
-
- _\b4_\b._\b4_\b._\b5 _\bS_\bT_\bA_\bS_\bH
-
- Since subroutines are not explicitly implemented in
- INTERCAL, the NEXT and RESUME statements must be used to
- execute common routines. However, as these routines might
- use the same variables as the main program, it is necessary
- for them to save the values of any variables whose values
- they alter, and later restore them. This process is
- simplified by the STASH statement, which has the form DO
- STASH list, where list represents a string of one or more
- variable or array names, separated by intersections (+).
- Thus
-
- PLEASE STASH .123+:123+,123
-
- stashes the values of two variables and one entire array.
- The values are left intact, and copies thereof are saved for
- later retrieval by (what else?) the RETRIEVE statement (see
- section ). It is not possible to STASH single array items.
-
- _\b4_\b._\b4_\b._\b6 _\bR_\bE_\bT_\bR_\bI_\bE_\bV_\bE
-
- PLEASE RETRIEVE list restores the previously STASHed values
- of the variables and arrays named in the list. If a value
- has been stashed more than once, the most recently STASHed
- values are RETRIEVEd, and a second RETRIEVE will restore the
- second most recent values STASHed. Attempting to RETRIEVE a
- value which has not been STASHed will result in the error
- message, "THROW STICK BEFORE RETRIEVING."
-
- _\b4_\b._\b4_\b._\b7 _\bI_\bG_\bN_\bO_\bR_\bE
-
- The statement DO IGNORE list causes all subsequent
- statements to have no effect upon variables and/or arrays
- named in the list. Thus, for example, after the sequence
-
- DO .1 <- #1
- PLEASE IGNORE .1
-
-
-
-
-
-
-
-
- - 17 -
-
-
-
- DO .1 <- #0
-
- 16-bit variable number 1 would have the value 1, not 0.
- Inputting (see section ) into an IGNOREd variable also has
- no effect. The condition is annulled via the REMEMBER
- statement (see section ). Note that, when a variable is
- being IGNOREd, its value, though immutable, is still
- available for use in expressions and the like.
-
- _\b4_\b._\b4_\b._\b8 _\bR_\bE_\bM_\bE_\bM_\bB_\bE_\bR
-
- PLEASE REMEMBER list terminates the effect of the IGNORE
- statement for all variables and/or arrays named in the list.
- It does not matter if a variable has been IGNOREd more than
- once, nor is it an error if the variable has not been
- IGNOREd at all.
-
- _\b4_\b._\b4_\b._\b9 _\bA_\bB_\bS_\bT_\bA_\bI_\bN
-
- INTERCAL contains no simple equivalent to an IF statement or
- computed GO TO, making it difficult to combine similar
- sections of code into a single routine which occasionally
- skips around certain statements. The IGNORE statement (see
- section ) is helpful in some cases, but a more viable method
- is often required. In keeping with the goal of INTERCAL
- having nothing in common with any other language, this is
- made possible via the ABSTAIN statement.
-
- This statement takes on one of two forms. It may not take on
- both at any one time. DO ABSTAIN FROM (label) causes the
- statement whose logical line label is (label) to be
- abstained from. PLEASE ABSTAIN FROM gerund list causes all
- statements of the specified type(s) to be abstained from, as
- in
-
- PLEASE ABSTAIN FROM STASHING
- PLEASE ABSTAIN FROM IGNORING + FORGETTING
- PLEASE ABSTAIN FROM NEXTING
- or PLEASE ABSTAIN FROM CALCULATING
-
- Statements may also be automatically abstained from at the
- start of execution via the NOT or N'T parameter (see section
- ).
-
- If, in the course of execution, a statement is encountered
- which is being abstained from, it is ignored and control
- passes to the next statement in the program (unless it, too,
- is being abstained from).
-
- The statement DO ABSTAIN FROM ABSTAINING is perfectly valid,
- as is DO ABSTAIN FROM REINSTATING (although this latter is
- not usually recommended). However, the statement DO ABSTAIN
- FROM GIVING UP is not accepted, even though DON'T GIVE UP
- is.
-
-
-
-
-
-
-
-
- - 18 -
-
-
-
- _\b4_\b._\b4_\b._\b1_\b0 _\bR_\bE_\bI_\bN_\bS_\bT_\bA_\bT_\bE
-
- The REINSTATE statement, like the ABSTAIN, takes as an
- argument either a line label or a gerund list. No other form
- of argument is permitted. For example, the following is an
- invalid argument:
-
- Given: x!=0, y!=0, Prove: x+y=0
- Since x!=0, then x+1!=1, x+a!=a, x+y!=y.
- But what is y? y is anything but 0.
- Thus x+y != anything but 0.
- Since x+y cannot equal anything but 0, x+y=0.
- Q.E.D.
-
- REINSTATEment nullifies the effects of an abstention. Either
- form of REINSTATEment can be used to "free" a statement,
- regardless of whether the statement was abstained from by
- gerund list, line label, or NOT. Thus, PLEASE REINSTATE
- REINSTATING is not necessarily an irrelevant statement,
- since it might free a DON'T REINSTATE command or a REINSTATE
- the line label of which was abstained from. However, DO
- REINSTATE GIVING UP is invalid, and attempting to REINSTATE
- a GIVE UP statement by line label will have no effect. Note
- that this insures that DON'T GIVE UP will always be a "do-
- nothing" statement.
-
- _\b4_\b._\b4_\b._\b1_\b1 _\bG_\bI_\bV_\bE _\bU_\bP
-
- PLEASE GIVE UP is used to exit from a program. It has the
- effect of a PLEASE RESUME #80. DON'T GIVE UP, as noted in
- section , is effectively a null statement.
-
- _\b4_\b._\b4_\b._\b1_\b2 _\bI_\bn_\bp_\bu_\bt
-
- Input is accomplished with the statement DO WRITE IN list,
- where list represents a string of variables and/or elements
- of arrays, separated by intersections. Numbers are
- represented on cards, each number on a separate card, by
- spelling out each digit (in English) and separating the
- digits with one or more spaces. A zero (0) may be spelled as
- either ZERO or OH. Thus the range of (32-bit) input values
- permissible extends from ZERO (or OH) through FOUR TWO NINE
- FOUR NINE SIX SEVEN TWO NINE FIVE.
-
- Attempting to write in a value greater than or equal to SIX
- FIVE FIVE THREE SIX for a 16-bit variable will result in the
- error message, "DON'T BYTE OFF MORE THAN YOU CAN CHEW."
-
- _\b4_\b._\b4_\b._\b1_\b3 _\bO_\bu_\bt_\bp_\bu_\bt
-
- Values may be output to the printer, one value per line, via
- the statement DO READ OUT list, where the list contains
- variables, array elements, and/or constants. Output is in
- the form of "extended" Roman numerals (also called
-
-
-
-
-
-
-
-
- - 19 -
-
-
-
- "butchered" Roman numerals), with an overline indicating the
- value below is "times 1000", and lower-case letters
- indicating "times 1000000". Zero is indicated by an overline
- with no character underneath. Thus, the range of (32-bit)
- output values possible is from
- _
-
- through
- __ ____________
- ivccxcivCMLXVIICCXCV.
- Note: For values whose residues modulo 1000000 are less than
- 4000, M is used to represent 1000; for values whose residues
- are 4000 or greater,
- _
- I
- is used. Thus #3999 would read out as MMMCMXCIX 3 while
- #4000 would readout as
- __
- IV
- Similar rules apply to the use of
- _
- M
- and i for 1000000, and to that of m and
- _
- i
- for 1000000000.
-
- _\b4_\b._\b5 _\bC_\bo_\bm_\bm_\be_\bn_\bt_\bs
-
- Unrecognizable statements, as noted in section , are flagged
- with a splat (*) during compilation, and are not considered
- fatal errors unless they are encountered during execution,
- at which time the statement (as input at compilation time)
- is printed and execution is terminated. This allows for an
- interesting (and, by necessity, unique) means of including
- comments in an INTERCAL listing. For example, the statement:
-
- * PLEASE NOTE THAT THIS LINE HAS NO EFFECT
-
- will be ignored during execution due to the inclusion of the
- NOT qualifier. User-supplied error messages are also easy
- to implement:
-
- * DO SOMETHING ABOUT OVERFLOW IN ;3
-
- as are certain simple conditional errors:
-
-
-
- ____________________
-
- 3. The original INTERCAL-72 manual claimed that #3999 should
- render as MMMIM, but the C-INTERCAL developers have been
- unable to find an algorithm that does this and is
- consistent with the rest of the rules.
-
-
-
-
-
-
-
- - 20 -
-
-
-
- * (123) DON'T YOU REALIZE THIS STATEMENT SHOULD ONLY BE ENCOUNTERED
- ONCE?
- PLEASE REINSTATE (123)
-
- This pair of statements will cause an error exit the second
- time they are encountered. Caution!! The appearance of a
- statement identifier in an intended comment will be taken as
- the beginning of a new statement. Thus, the first comment
- example above could not have been:
-
- * PLEASE NOTE THAT THIS LINE DOES NOTHING
-
- The third example, however, is valid, despite the appearance
- of two cases of D-space-O, since INTERCAL does not ignore
- extraneous spaces in statement identifiers.
-
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- - 21 -
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-
- _\b5_\b. _\bS_\bU_\bB_\bR_\bO_\bU_\bT_\bI_\bN_\bE _\bL_\bI_\bB_\bR_\bA_\bR_\bY
-
- INTERCAL provides several built-in subroutines to which
- control can be transferred to perform various operations.
- These operations include many useful functions which are not
- easily representable in INTERCAL, such as addition,
- subtraction, etc.
-
- _\b5_\b._\b1 _\bU_\bs_\ba_\bg_\be
-
- In general, the operands are .1, .2, etc., or :1, :2, etc.,
- and the result(s) are stored in what would have been the
- next operand(s). For instance, one routine adds .1 to .2 and
- stores the sum in .3, with .4 being used to indicate
- overflow. All variables not used for results are left
- unchanged.
-
- _\b5_\b._\b2 _\bA_\bv_\ba_\bi_\bl_\ba_\bb_\bl_\be _\bF_\bu_\bn_\bc_\bt_\bi_\bo_\bn_\bs
-
- At the time of this writing, only the most fundamental
- operations are offered in the library, as a more complete
- selection would require prohibitive time and core to
- implement. These functions, along with their corresponding
- entry points (entered via DO (entry) NEXT) are listed below.
-
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- - 22 -
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-
- (1000) .3 <- .1 plus .2, error exit on overflow
- (1009) .3 <- .1 plus .2
- .4 <- #1 if no overflow, else .4 <- #2
- (1010) .3 <- .1 minus .2, no action on overflow
- (1020) .1 <- .1 plus #1, no action on overflow
- (1030) .3 <- .1 times .2, error exit on overflow
- (1039) .3 <- .1 times .2
- .4 <- #1 if no overflow, else .4 <- #2
- (1040) .3 <- .1 divided by .2
- .3 <- #0 if .2 is #0
- (1050) .2 <- :1 divided by .1, error exit on overflow
- .2 <- #0 if .1 is #0
-
- (1500) :3 <- :1 plus :2, error exit on overflow
- (1509) :3 <- :1 plus :2
- :4 <- #1 if no overflow, else :4 <- #2
- (1510) :3 <- :1 minus :2, no action on overflow
- (1520) :1 <- .1 concatenated with .2
- (1525) This subroutine is intended solely for internal
- use within the subroutine library and is therefore
- not described here. Its effect is to shift .3
- logically 8 bits to the left.
- (1530) :1 <- .1 times .2
- (1540) :3 <- :1 times :2, error exit on overflow
- (1549) :3 <- :1 times :2
- :4 <- #1 if no overflow, else :4 <- #2
- (1550) :3 <- :1 divided by :2
- :3 <- #0 if :2 is #0
-
- (1900) .1 <- uniform random no. from #0 to #65535
- (1910) .2 <- normal random no. from #0 to .1, with
- standard deviation .1 divided by #12
-
-
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- - 23 -
-
-
-
- _\b6_\b. _\bP_\bR_\bO_\bG_\bR_\bA_\bM_\bM_\bI_\bN_\bG _\bH_\bI_\bN_\bT_\bS
-
- For the user looking to become more familiar with the
- INTERCAL language, we present in this section an analysis of
- a complex program, as well as some suggested projects for
- the ambitious programmer.
-
- Considering the effort involved in writing an INTERCAL
- program, it was decided in putting together this manual to
- use an already existing program for instructive analysis.
- Since there was only one such program available, we have
- proceeded to use it. It is known as the "INTERCAL System
- Library."
-
- _\b6_\b._\b1 _\bD_\be_\bs_\bc_\br_\bi_\bp_\bt_\bi_\bo_\bn
-
- The program listing is in section . It is in the same format
- as would be produced by the Princeton INTERCAL compiler in
- FORMAT mode with WIDTH=62 (see section ). For a description
- of the functions performed by the Library, see section .
-
- _\b6_\b._\b2 _\bA_\bn_\ba_\bl_\by_\bs_\bi_\bs
-
- We shall not attempt to discuss here the algorithms used,
- but rather we shall point out some of the general techniques
- applicable to a wide range of problems.
-
- Statements 10, 14, 15, and 26 make up a virtual "computed GO
- TO". When statement 10 is executed, control passes
- eventually to statement 16 or 11, depending on whether .5
- contains #1 or #2, respectively. The value of .5 is
- determined in statement 9, which demonstrates another handy
- technique. To turn an expression, exp, with value #0 or #1,
- into #1 or #2 (for use in a "GO TO"), use "V\b-'exp'c\b/#1"~#3.
- To reverse the condition (i.e., convert #0 to #2 and leave
- #1 alone) use "V\b-'exp'c\b/#2"~#3.
-
- Certain conditions are easily checked. For example, to test
- for zero, select the value from itself and select the bottom
- bit (see statement 54). To test for all bits being 1's,
- select the value from itself and select the top bit. The
- test for greater than, performed in statements 219 and 220
- on 32-bit values, employs binary logical operations, which
- are performed as follows:
-
- 'V\b-.1c\b/.2'~'#0c\b/#65535'
-
- for 16-bit values or, for 32-bit values:
-
- "'V\b-":1~'#65535c\b/30'"c\b/":2~'#65535c\b/#0'"'~'#0
- c\b/#65535'"c\b/"'V\b-":1~'#0c\b/#65535'"c\b/":2~'#0
- c\b/#65535'"'~'#0c\b/#65535'"
-
- (The proofs are left as an exercise to the reader.)
-
-
-
-
-
-
-
-
- - 24 -
-
-
-
- Testing for greater-than with 16-bit values is somewhat
- simpler and is done with the pair of statements:
-
- DO .C <- 'V\b-.Ac\b/.B'~'#0c\b/#65535'
- DO .C <- '&"'.A~.C'~'"V\b-'V\b-.C~.C'c\b/#32768"
- ~"#0c\b/#65535"'"c\b/".C~.C"'~#1
-
- This sets .C (a dummy variable) to #1 if .A > .B, and #0
- otherwise. The expression may be expanded as described above
- to instead set .C to #1 or #2.
-
- Note also in statement 220 the occurrence of
- ~"#65535c\b/#65535". Although these operations select the
- entire value, they are not extraneous, as they ensure that
- the forthcoming V\b-s will be operating on 32-bit values.
-
- In several virtual computed GO TOs the DO FORGET #1
- (statement 15 in the earlier example) has been omitted,
- since the next transfer of control would be a DO RESUME #1.
- By making this a DO RESUME #2 instead, the FORGET may be
- forgotten.
-
- In statement 64, note that .2 is STASHed twice by a single
- statement. This is perfectly legal.
-
- Lastly, note in statements 243 and 214 respectively,
- expressions for shifting 16- and 32-bit variables logically
- one place to the left. Statement 231 demonstrates right-
- shifting for 32-bit variables.
-
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- - 25 -
-
-
-
- _\b6_\b._\b3 _\bP_\br_\bo_\bg_\br_\ba_\bm _\bL_\bi_\bs_\bt_\bi_\bn_\bg
-
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- - 26 -
-
-
-
- 1 (1000) PLEASE IGNORE .4
- 2 PLEASE ABSTAIN FROM (1005)
- 3 (1009) DO STASH .1 + .2 + .5 + .6
- 4 DO .4 <- #1
- 5 DO (1004) NEXT
- 6 (1004) PLEASE FORGET #1
- 7 DO .3 <- 'V\b-.1c\b/.2'~'#0c\b/#65535'
- 8 DO .6 <- '&.1c\b/.2'~'#0c\b/#65535'
- 9 PLEASE DO .5 <- "V\b-!6~#32768'c\b/#1"~#3
- 10 DO (1002) NEXT
- 11 DO .4 <- #2
- 12 (1005) DO (1006) NEXT
- * 13 (1999) DOUBLE OR SINGLE PRECISION OVERFLOW
- 14 (1002) DO (1001) NEXT
- 15 (1006) PLEASE FORGET #1
- 16 DO .5 <- 'V\b-"!6~.6'~#1"c\b/#1'~#3
- 17 DO (1003) NEXT
- 18 DO .1 <- .3
- 19 DO .2 <- !6c\b/#0'~'#32767c\b/#1'
- 20 DO (1004) NEXT
- 21 (1003) DO (1001) NEXT
- 22 DO REINSTATE (1005)
- 23 (1007) PLEASE RETRIEVE .1 + .2 + .5 + .6
- 24 DO REMEMBER .4
- 25 PLEASE RESUME #2
- 26 (1001) DO RESUME .5
- 27 (1010) DO STASH .1 + .2 + .4
- 28 DO .4 <- .1
- 29 DO .1 <- 'V\b-.2c\b/#65535'~'#0c\b/#65535'
- 30 DO (1020) NEXT
- 31 PLEASE DO .2 <- .4
- 32 PLEASE DO (1009) NEXT
- 33 DO RETRIEVE .1 + .2 + .4
- 34 PLEASE RESUME #1
- 35 (1020) DO STASH .2 + .3
- 36 DO .2 <- #1
- 37 PLEASE DO (1021) NEXT
- 38 (1021) DO FORGET #1
- 39 DO .3 <- "V\b-!1~.2'c\b/#1"~#3
- 40 PLEASE DO .1 <- 'V\b-.1c\b/.2'~'#0c\b/#65535'
- 41 DO (1022) NEXT
- 42 DO .2 <- !2c\b/#0'~'#32767c\b/#1'
- 43 DO (1021) NEXT
- 44 (1023) PLEASE RESUME .3
- 45 (1022) DO (1023) NEXT
- 46 PLEASE RETRIEVE .2 + .3
- 47 PLEASE RESUME #2
- 48 (1030) DO ABSTAIN FROM (1033)
- 49 PLEASE ABSTAIN FROM (1032)
- 50 (1039) DO STASH :1 + .5
- 51 DO (1530) NEXT
- 52 DO .3 <- :1~#65535
- 53 PLEASE DO .5 <- :1~'#65280c\b/#65280'
- 54 DO .5 <- 'V\b-"!5~.5'~#1"c\b/#1'~#3
-
-
-
-
-
-
-
-
- - 27 -
-
-
-
- 55 DO (1031) NEXT
- 56 (1032) DO (1033) NEXT
- 57 DO (1999) NEXT
- 58 (1031) DO (1001) NEXT
- 59 (1033) DO .4 <- .5
- 60 DO REINSTATE (1032)
- 61 PLEASE REINSTATE (1033)
- 62 DO RETRIEVE :1 + .5
- 63 PLEASE RESUME #2
- 64 (1040) PLEASE STASH .1 + .2 + .2 + :1 + :2 + :3
- 65 DO .2 <- #0
- 66 DO (1520) NEXT
- 67 DO STASH :1
- 68 PLEASE RETRIEVE .2
- 69 DO .1 <- .2
- 70 DO .2 <- #0
- 71 PLEASE DO (1520) NEXT
- 72 DO :2 <- :1
- 73 DO RETRIEVE .1 + .2 + :1
- 74 DO (1550) NEXT
- 75 PLEASE DO .3 <- :3
- 76 DO RETRIEVE :1 + :2 + :3
- 77 DO RESUME #1
- 78 (1050) PLEASE STASH :2 + :3 + .5
- 79 DO :2 <- .1
- 80 PLEASE DO (1550) NEXT
- 81 DO .5 <- :3~'#65280c\b/#65280'
- 82 DO .5 <- 'V\b-"!5~.5'~#1"c\b/#1'~#3
- 83 DO (1051) NEXT
- 84 DO (1999) NEXT
- 85 (1051) DO (1001) NEXT
- 86 DO .2 <- :3
- 87 PLEASE RETRIEVE :2 + :3 + .5
- 88 DO RESUME #2
- 89 (1500) PLEASE ABSTAIN FROM (1502)
- 90 PLEASE ABSTAIN FROM (1506)
- 91 (1509) PLEASE STASH :1 + .1 + .2 + .3 + .4 + .5 + .6
- 92 DO .1 <- :1~#65535
- 93 PLEASE DO .2 <- :2~#65535
- 94 DO (1009) NEXT
- 95 DO .5 <- .3
- 96 PLEASE DO .6 <- .4
- 97 DO .1 <- :1~'#65280c\b/#65280'
- 98 DO .2 <- :2~'#65280c\b/#65280'
- 99 DO (1009) NEXT
- 100 DO .1 <- .3
- 101 PLEASE DO (1503) NEXT
- 102 DO .6 <- .4
- 103 DO .2 <- #1
- 104 DO (1009) NEXT
- 105 DO .1 <- .3
- 106 DO (1501) NEXT
- 107 (1504) PLEASE RESUME .6
- 108 (1503) DO (1504) NEXT
-
-
-
-
-
-
-
-
- - 28 -
-
-
-
- 109 (1501) DO .2 <- .5
- 110 DO .5 <- 'V\b-"'&.6c\b/.4'~#1"c\b/#2'~#3
- 111 DO (1505) NEXT
- 112 (1506) DO (1502) NEXT
- 113 PLEASE DO (1999) NEXT
- 114 (1505) DO (1001) NEXT
- 115 (1502) DO :4 <- .5
- 116 DO (1520) NEXT
- 117 DO :3 <- :1
- 118 PLEASE RETRIEVE :1 + .1 + .2 + .3 + .4 + .5 + .6
- 119 DO REINSTATE (1502)
- 120 DO REINSTATE (1506)
- 121 PLEASE RESUME #3
- 122 (1510) DO STASH :1 + :2 + :4
- 123 DO :1 <- "'V\b-":2~'#65535c\b/#0'"c\b/#65535'
- ~'#0c\b/#65535'"c\b/"'V\b-":2~'#0c\b/#65535'
- "c\b/#65535'~'#0c\b/#65535'"
- 124 DO :2 <- #1
- 125 DO (1509) NEXT
- 126 PLEASE RETRIEVE :1
- 127 DO :2 <- :3
- 128 PLEASE DO (1509) NEXT
- 129 DO RETRIEVE :2 + :4
- 130 PLEASE RESUME #1
- 131 (1520) PLEASE STASH .3 + .4
- 132 DO .3 <- .1~#43690
- 133 DO (1525) NEXT
- 134 PLEASE DO .4 <- 'V.3c\b/".2~#43690"'~'#0c\b/#65535'
- 135 DO .3 <- .1~#21845
- 136 PLEASE DO (1525) NEXT
- 137 DO :1 <- .4c\b/"'V.3c\b/".2~#21845"'~'#0c\b/#65535'"
- 138 PLEASE RETRIEVE .3 + .4
- 139 DO RESUME #1
- 140 (1525) DO .3 <- '"'"'"!3c\b/#0'~'#32767c\b/#1'"c\b/#0'
- ~'#32767c\b/#1'"c\b/#0'~'#16383c\b/#3'"c\b/#0'
- ~'#4095c\b/#15'
- 141 PLEASE RESUME #1
- 142 (1530) DO STASH :2 + :3 + .3 + .5
- 143 DO :1 <- #0
- 144 DO :2 <- .2
- 145 DO .3 <- #1
- 146 DO (1535) NEXT
- 147 (1535) PLEASE FORGET #1
- 148 DO .5 <- "V\b-!1~.3'c\b/#1"~#3
- 149 DO (1531) NEXT
- 150 DO (1500) NEXT
- 151 DO :1 <- :3
- 152 PLEASE DO (1533) NEXT
- 153 (1531) PLEASE DO (1001) NEXT
- 154 (1533) DO FORGET #1
- 155 DO .3 <- !3c\b/#0'~'#32767c\b/#1'
- 156 DO :2 <- ":2~'#0c\b/#65535'"c\b/"'":2~'#32767
- c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- 157 PLEASE DO .5 <- "V\b-!3~.3'c\b/#1"~#3
-
-
-
-
-
-
-
-
- - 29 -
-
-
-
- 158 DO (1532) NEXT
- 159 DO (1535) NEXT
- 160 (1532) DO (1001) NEXT
- 161 PLEASE RETRIEVE :2 + :3 + .3 + .5
- 162 DO RESUME #2
- 163 (1540) PLEASE ABSTAIN FROM (1541)
- 164 DO ABSTAIN FROM (1542)
- 165 (1549) PLEASE STASH :1 + :2 + :4 + :5 + .1 + .2 + .5
- 166 DO .1 <- :1~#65535
- 167 PLEASE DO .2 <- :2~'#65280c\b/#65280'
- 168 DO .5 <- :1~'#65280c\b/#65280'
- 169 DO (1530) NEXT
- 170 DO :3 <- :1
- 171 DO .2 <- :2~#65535
- 172 PLEASE DO (1530) NEXT
- 173 DO :5 <- :1
- 174 DO .1 <- .5
- 175 DO (1530) NEXT
- 176 DO :4 <- :1
- 177 PLEASE DO :1 <- ":3~'#65280c\b/#65280'"
- c\b/":4~'#65280c\b/#65280'"
- 178 DO .5 <- ':1~:1'~#1
- 179 DO .2 <- :2~'#65280c\b/#65280'
- 180 DO (1530) NEXT
- 181 PLEASE DO .5 <- '"':1~:1'~#1"c\b/.5'~#3
- 182 DO .1 <- :3~#65535
- 183 DO .2 <- #0
- 184 DO (1520) NEXT
- 185 PLEASE DO :2 <- :1
- 186 PLEASE DO .1 <- :4~#65535
- 187 DO (1520) NEXT
- 188 DO (1509) NEXT
- 189 DO .5 <- !5c\b/":4~#3"'~#15
- 190 DO :1 <- :3
- 191 DO :2 <- :5
- 192 DO (1509) NEXT
- 193 PLEASE DO .5 <- !5c\b/":4~#3"'~#172
- 194 DO .5 <- 'V\b-"!5~.5'~#1"c\b/#1'~#3
- 195 PLEASE RETRIEVE :4
- 196 (1541) DO :4 <- .5
- 197 DO (1543) NEXT
- 198 (1542) DO (1544) NEXT
- 199 PLEASE DO (1999) NEXT
- 200 (1543) DO (1001) NEXT
- 201 (1544) DO REINSTATE (1541)
- 202 PLEASE REINSTATE (1542)
- 203 PLEASE RETRIEVE :1 + :2 + :5 + .1 + .2 + .5
- 204 DO RESUME #2
- 205 (1550) DO STASH :1 + :4 + :5 + .5
- 206 DO :3 <- #0
- 207 DO .5 <- 'V\b-"':2~:2'~#1"c\b/#1'~#3
- 208 PLEASE DO (1551) NEXT
- 209 DO :4 <- #1
- 210 PLEASE DO (1553) NEXT
-
-
-
-
-
-
-
-
- - 30 -
-
-
-
- 211 (1553) DO FORGET #1
- 212 DO .5 <- 'V\b-":2~'#32768c\b/#0'"c\b/#2'~#3
- 213 DO (1552) NEXT
- 214 DO :2 <- ":2~'#0c\b/#65535'"c\b/"'":2~'#32767
- c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- 215 PLEASE DO :4 <- ":4~'#0c\b/#65535'"c\b/"'":4
- ~'#32767c\b/#0'"c\b/#0'~'#32767c\b/#1'"
- 216 DO (1553) NEXT
- 217 (1552) DO (1001) NEXT
- 218 (1556) PLEASE FORGET #1
- 219 DO :5 <- "'V\b-":1~'#65535c\b/#0'"c\b/":2
- ~'#65535c\b/#0'"'~'#0c\b/#65535'"c\b/"'
- V\b-":1~'#0c\b/#65535'"c\b/":2~'#0c\b/
- #65535'"'~'#0c\b/#65535'"
- 220 DO .5 <- 'V\b-"'&"':2~:5'~'"'V\b-"'V\b-":5~:5
- "~"#65535c\b/#65535"'~'#65535c\b/#0'"c\b/
- #32768'~'#0c\b/#65535'"c\b/"'V\b-":5~:5"
- ~"#65535c\b/#65535"'~'#0c\b/#65535'"'"c\b/"'
- :5~:5'~#1"'~#1"c\b/#2'~#3
- 221 DO (1554) NEXT
- 222 DO :5 <- :3
- 223 DO (1510) NEXT
- 224 PLEASE DO :1 <- :3
- 225 DO :3 <- "'V":4~'#65535c\b/#0'"c\b/":5~'#65535
- c\b/#0'"'~'#0c\b/#65535'"c\b/"'V":4~'#0
- c\b/#65535'"c\b/":5~'#0c\b/#65535'"'~'#0
- c\b/#65535'"
- 226 DO (1555) NEXT
- 227 (1554) PLEASE DO (1001) NEXT
- 228 (1555) DO FORGET #1
- 229 DO .5 <- "V\b-':4~#1'c\b/#2"~#3
- 230 DO (1551) NEXT
- 231 DO :2 <- ":2~'#0c\b/#65534'"c\b/":2~'#65535c\b/#0'"
- 232 DO :4 <- ":4~'#0c\b/#65534'"c\b/":4~'#65535c\b/#0'"
- 233 PLEASE DO (1556) NEXT
- 234 (1551) DO (1001) NEXT
- 235 PLEASE RETRIEVE :1 + :4 + :5 + .5
- 236 PLEASE RESUME #2
- 237 (1900) DO STASH .2 + .3 + .5
- 238 DO .1 <- #0
- 239 DO .2 <- #1
- 240 PLEASE DO (1901) NEXT
- 241 (1901) DO FORGET #1
- 242 DO %50 .1 <- 'V.1c\b/.2'~'#0c\b/#65535'
- 243 DO .2 <- !2c\b/#0'~'#32767c\b/#1'
- 244 PLEASE DO .5 <- "V\b-!2~.2'c\b/#1"~#3
- 245 DO (1902) NEXT
- 246 DO (1901) NEXT
- 247 (1902) DO (1001) NEXT
- 248 DO RETRIEVE .2 + .3 + .5
- 249 PLEASE RESUME #2
- 250 (1910) PLEASE STASH .1 + .3 + .5 + :1 + :2 + :3
- 251 DO .3 <- #65524
- 252 DO :1 <- #6
-
-
-
-
-
-
-
-
- - 31 -
-
-
-
- 253 DO (1911) NEXT
- * 254 PLEASE NOTE THAT YOU CAN'T GET THERE FROM HERE
- 255 (1912) DO (1001) NEXT
- 256 (1911) DO FORGET #1
- 257 PLEASE DO (1900) NEXT
- 258 DO :2 <- .1
- 259 DO (1500) NEXT
- 260 PLEASE DO :1 <- :3
- 261 DO .1 <- .3
- 262 DO (1020) NEXT
- 263 PLEASE DO .3 <- .1
- 264 DO .5 <- 'V\b-"!3~.3'~#1"c\b/#2'~#3
- 265 DO (1912) NEXT
- 266 DO .1 <- #12
- 267 PLEASE DO (1050) NEXT
- 268 DO RETRIEVE .1
- 269 DO (1530) NEXT
- 270 DO :2 <- #32768
- 271 DO (1500) NEXT
- 272 PLEASE DO .2 <- :3~'#65280c\b/#65280'
- 273 PLEASE RETRIEVE .3 + .5 + :1 + :2 + :3
- 274 DO RESUME #1
-
-
-
-
-
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- - 32 -
-
-
-
- _\b6_\b._\b4 _\bP_\br_\bo_\bg_\br_\ba_\bm_\bm_\bi_\bn_\bg _\bS_\bu_\bg_\bg_\be_\bs_\bt_\bi_\bo_\bn_\bs
-
- For the novice INTERCAL programmer, we provide here a list
- of suggested INTERCAL programming projects:
-
- Write an integer exponentiation subroutine. :1 <- .1 raised
- to the .2 power.
-
- Write a double-precision sorting subroutine. Given 32-bit
- array ;1 of size :1, sort the contents into numerically
- increasing order, leaving the results in ;1.
-
- Generate a table of prime numbers.
-
- Put together a floating-point library, using 32-bit
- variables to represent floating-point numbers (let the upper
- half be the mantissa and the lower half be the
- characteristic). The library should be capable of
- performing floating-point addition, subtraction,
- multiplication, and division, as well as the natural
- logarithm function.
-
- Program a Fast Fourier Transform (FFT). This project would
- probably entail the writing of the floating-point library as
- well as sine and cosine functions.
-
- Calculate, to :1 places, the value of pi.
-
-
-
-
-
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-
-
-
-
-
-
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-
- - 33 -
-
-
-
- _\b7_\b. _\bE_\bR_\bR_\bO_\bR _\bM_\bE_\bS_\bS_\bA_\bG_\bE_\bS
-
- Due to INTERCAL's implementation of comment lines (see
- section 4.5), most error messages are produced during
- execution instead of during compilation. All errors except
- those not causing immediate termination of program execution
- are treated as fatal.
-
- _\b7_\b._\b1 _\bF_\bo_\br_\bm_\ba_\bt
-
- All error messages appear in the following form:
-
- ICLnnnI (error message)
- ON THE WAY TO STATEMENT nnnn
- CORRECT SOURCE AND RESUBMIT
-
- The message varies depending upon the error involved. For
- undecodable statements the message is the statement itself.
- The second line tells which statement would have been
- executed next had the error not occurred. Note that if the
- error is due to 80 attempted levels of NEXTing, the
- statement which would have been executed next need not be
- anywhere near the statement causing the error.
-
- _\b7_\b._\b2 _\bM_\be_\bs_\bs_\ba_\bg_\be_\bs
-
- Brief descriptions of the different error types are listed
- below according to message number.
-
- 000 An undecodable statement has been encountered in the
- course of execution. Note that keypunching errors can
- be slightly disastrous, since if 'FORGET' were
- misspelled F-O-R-G-E-R, the results would probably not
- be those desired. Extreme misspellings may have even
- more surprising consequences. For example, misspelling
- 'FORGET' R-E-S-U-M-E could have drastic results.
-
- 017 An expression contains a syntax error.
-
- 079 Improper use has been made of statement identifiers.
-
- 099 Improper use has been made of statement identifiers.
-
- 123 Program has attempted 80 levels of NEXTing.
-
- 129 Program has attempted to transfer to a non-existent
- line label.
-
- 139 An ABSTAIN or REINSTATE statement references a non-
- existent line label.
-
- 182 A line label has been multiply defined.
-
-
-
-
-
-
-
-
-
-
- - 34 -
-
-
-
- 197 An invalid line label has been encountered.
-
- 200 An expression involves an unidentified variable.
-
- 240 An attempt has been made to give an array a dimension
- of zero.
-
- 241 Invalid dimensioning information was supplied in
- defining or using an array.
-
- 275 A 32-bit value has been assigned to a 16-bit variable.
-
- 436 A retrieval has been attempted for an unSTASHed value.
-
- 533 A WRITE IN statement or interleave (c\b/) operation has
- produced a value requiring over 32 bits to represent.
-
- 562 Insufficient data.
-
- 579 Input data is invalid.
-
- 621 The expression of a RESUME statement evaluated to #0.
-
- 632 Program execution was terminated via a RESUME statement
- instead of GIVE UP.
-
- 633 Execution has passed beyond the last statement of the
- program.
-
- 774 A compiler error has occurred (see section ).
-
- 778 An unexplainable compiler error has occurred (see J.
- Lyon or D. Woods).
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
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-
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-
-
-
-
-
- - 35 -
-
-
-
- _\b8_\b. _\bJ_\bC_\bL
-
- The information contained in the following section applies
- only to the Princeton compiler, run under OS/360.
-
- _\b8_\b._\b1 _\bT_\bh_\be _\bP_\br_\bi_\bn_\bc_\be_\bt_\bo_\bn _\bC_\bo_\bm_\bp_\bi_\bl_\be_\br
-
- The Princeton compiler, written in SPITBOL (a variant of
- SNOBOL), performs the compilation in two stages. First the
- INTERCAL source is converted into SPITBOL source, then the
- latter is compiled and executed.
-
- It should be noted that the Princeton compiler fails to
- properly interpret certain multiply-subscripted expressions,
- such as:
-
- ",1SUB",2SUB#1"#2"
-
-
- This is not a "bug". Being documented, it is merely a
- "restriction". Such cases may be resolved by alternating
- sparks and ears in various levels of expression nesting:
-
- ",1SUB',2SUB#1'#2"
-
- which is advisable in any case, since INTERCAL expressions
- are unreadable enough as is.
-
- Since there is currently no catalogued procedure for
- invoking the compiler, the user must include the in-line
- procedure shown in Figure 3 in his job before the
- compilation step. Copies of this in-line procedure may be
- obtained at any keypunch if the proper keys are struck.
-
- The compiler is then executed in the usual manner:
-
-
- // EXEC INTERCAL[,PARM='parameters']
- //COMPILE.SYSIN DD *
- {INTERCAL source deck}
- /*
- //EXECUTE.SYSWRITE DD *
- {input data}
- /*
-
-
- The various parameters are described following the in-line
- procedure. At most one parameter from each set may apply to
- a given compilation; if more than one are specified, the
- results are undefined, and may vary depending upon the
- particular set of options. The default parameters are
- underlined.
-
-
-
-
-
-
-
-
-
-
- - 36 -
-
-
-
- //INTERCAL PROC
- //COMPILE EXEC PGM=INTERCAL
- //STEPLIB DD DSN=U.INTERCAL.LIBRARY,DISP=SHR
- // DD DSN=SYS1.FORTLIB,DISP=SHR
- //SYSPRINT DD SYSOUT=A,DCB=(BLKSIZE=992,LRECL=137,RECFM=VBA)
- //SYSPUNCH DD DUMMY
- //SCRATCH DD DSN=&COMPSET,UNIT=SYSDA,SPACE=(CYL,(3,1)),DISP=(,PASS)
- //EXECUTE EXEC PGM=EXECUTE,COND=(4,LT)
- //SOURCES DD DSN=U.INTERCAL.SOURCES,DISP=SHR 4
- //STEPLIB DD DSN=U.INTERCAL.LIBRARY,DISP=SHR
- // DD DSN=SYS5.SPITLIB,DISP=SHR
- // DD DSN=SYS1.FORTLIB,DISP=SHR
- //SYSIN DD DSN=&COMPSET,DISP=(OLD,DELETE)
- //SYSOBJ DD SYSOUT=B,DCB=(BLKSIZE=80,LRECL=80,RECFM=F)
- //SYSPRINT DD SYSOUT=A,DCB=(BLKSIZE=992,LRECL=137,RECFM=VBA)
- //SYSPUNCH DD DUMMY
- // PEND
-
- Figure 3. Inline procedure for using INTERCAL.
-
- _\bO_\bP_\bT
- NOOPT
- In the default mode, the compiler will print a list of
- all options in effect, including the defaults for
- unspecified parameter groups and the effective option
- for those sets where one was specified. If NOOPT is
- requested, it causes the default mode to be assumed.
-
- _\bO_\bP_\bT_\bS_\bU_\bB
- NOOPTSUB
- NOSUB
- Unless 'NOOPTSUB' is requested, the System Library is
- optimized, resulting in much more rapid processing of
- function calls. Specifying NOOPTSUB causes the non-
- optimized INTERCAL code shown in section
- to be used, whereas NOSUB requests that the System
- Library be omitted altogether.
-
- IAMBIC
- _\bP_\bR_\bO_\bS_\bE
- The IAMBIC parameter permits the programmer to use
- poetic license and thus write in verse. If the reader
- does not believe it possible to write verse in
-
- ____________________
-
- 4. Pending acquisition of SPITBOL release 3.0, the SOURCES
- DD card must be replaced by the five cards:
-
- //NOOPTPFX DD DSN=U.INTERCAL.SOURCES(NOOPTPFX),DISP=SHR
- //NOOPTSUB DD DSN=U.INTERCAL.SOURCES(NOOPTSUB),DISP=SHR
- //OPTPFX DD DSN=U.INTERCAL.SOURCES(OPTPFX),DISP=SHR
- //OPTSUB DD DSN=U.INTERCAL.SOURCES(OPTSUB),DISP=SHR
- //PRELIM DD DSN=U.INTERCAL.SOURCES(PRELIM),DISP=SHR
-
-
-
-
-
-
-
-
- - 37 -
-
-
-
- INTERCAL, he should send the authors a stamped, self-
- addressed envelope, along with any INTERCAL program,
- and they will provide one which is verse.
-
- _\bF_\bO_\bR_\bM_\bA_\bT
- NOFORMAT
- In FORMAT mode, each statement printed is put on a
- separate line (or lines). In NOFORMAT mode, the free-
- format source is printed exactly as input. In this
- latter case, statement numbers are provided only for
- the first statement on a card, and they may be only
- approximate. Also, unrecognizable statements are not
- flagged.
-
- SEQ
- _\bN_\bO_\bS_\bE_\bQ
- If the source deck has sequence numbers in columns 73
- through 80, specifying 'SEQ' will cause them to be
- ignored.
-
- SOURCE
- _\bN_\bO_\bS_\bO_\bU_\bR_\bC_\bE
- If NOSOURCE is selected, all source listing is
- suppressed.
-
- LIST
- _\bN_\bO_\bL_\bI_\bS_\bT
- If LIST is specified, the compiler will provide a list
- of statement numbers catalogued according to type of
- statement. The compiler uses this table to perform
- abstentions by gerund.
-
- WIDTH=nn
- This sets the width (in number of characters) of the
- output line for FORMAT mode output. The default is 1\b13\b32\b2.\b.
-
- CODE
- _\bN_\bO_\bC_\bO_\bD_\bE
- Include 'CODE' in the parameter list to obtain a
- listing of the SPITBOL code produced for each INTERCAL
- statement.
-
- LINES=nn
- This determines the number of lines per page, during
- both compilation and execution. The default is 6\b60\b0.\b.
-
- DECK
- _\bN_\bO_\bD_\bE_\bC_\bK
- Selecting 'DECK' will cause the compiler to punch out a
- SPITBOL object deck which may then be run without
- reinvoking the INTERCAL (or SPITBOL) compiler.
-
- _\bK_\bI_\bD_\bD_\bI_\bN_\bG
-
-
-
-
-
-
-
-
-
- - 38 -
-
-
-
- NOKIDDING
- Select NOKIDDING to eliminate the snide remarks which
- ordinarily accompany INTERCAL error messages.
-
- _\bG_\bO
- NOGO
- Specifying 'NOGO' will cause the program to be
- compiled but not executed. EXECUTE/NOEXECUTE may be
- substituted for GO/NOGO, but this will result in an
- error, and GO will be assumed.
-
- _\bB_\bU_\bG
- NOBUG
- Under the default, there is a fixed probability of a
- fatal compiler bug being worked at random into the
- program being compiled. Encountering this bug during
- execution results in error message 774 (see section ).
- This probability is reduced to zero under 'NOBUG'. This
- does not affect the probability (presumably negligible)
- of error message 778.
-
- _\b8_\b._\b2 _\bO_\bt_\bh_\be_\br _\bI_\bN_\bT_\bE_\bR_\bC_\bA_\bL _\bC_\bo_\bm_\bp_\bi_\bl_\be_\br_\bs
-
- There are no other INTERCAL compilers. 5
-
-
-
-
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-
-
-
-
-
-
-
- ____________________
-
- 5. This assertion in the INTERCAL-72 manual was blatantly
- contradicted by some notes on an Atari implementation
- included at the end of the manual. So, you expect
- compiler manuals to be consistent?
-
-
-
-
-
-
-
- - 39 -
-
-
-
- T\bTO\bON\bNS\bSI\bIL\bL A\bA6\b6
-
-
-
-
-
-
-
- The Official INTERCAL Character Set
-
- Tabulated on page 39 are all the characters used in
- INTERCAL, excepting letters and digits, along with their
- names and interpretations. Also included are several
- characters not used in INTERCAL, which are presented for
- completeness and to allow for future expansion.
-
-
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-
-
-
-
-
-
- ____________________
-
- 6. Since all other reference manuals have Appendices, it was
- decided that the INTERCAL manual should contain some
- other type of removable organ.
-
- 7. This footnote intentionally unreferenced.
-
-
-
-
-
-
-
- - 40 -
-
-
-
- +--------------------------------------------------------------------------+
- |Character Name Use (if any) |
- |. spot identify 16-bit variable |
- |: two-spot identify 32-bit variable |
- |, tail identify 16-bit array |
- |; hybrid identify 32-bit array |
- |# mesh identify constant |
- |= half-mesh |
- |' spark grouper |
- |` backspark |
- |! wow equivalent to spark-spot |
- |? what _\bu_\bn_\ba_\br_\by _\be_\bx_\bl_\bu_\bs_\bi_\bv_\be _\bO_\bR _\b(_\bA_\bS_\bC_\bI_\bI_\b) |
- |" rabbit-ears grouper |
- |"\b. rabbit equivalent to ears-spot |
- || spike |
- |% double-oh-seven percentage qualifier |
- |- worm used with angles |
- |< angle used with worms |
- |> right angle |
- |( wax precedes line label |
- |) wane follows line label |
- |[ U turn |
- |] U turn back |
- |{ embrace |
- |} bracelet |
- |* splat flags invalid statements |
- |& ampersand 9 unary logical AND |
- |V V (or book) unary logical OR |
- |V\b- bookworm (or universal qualifier) unary exclusive OR |
- |$ big money _\bb_\bi_\bn_\ba_\br_\by _\bm_\bi_\bn_\bg_\bl_\be _\b(_\bA_\bS_\bC_\bI_\bI_\b) |
- |c\b/ change binary mingle |
- |~ sqiggle binary select |
- |_ flat worm |
- |- overline indicates "times 1000" |
- |+ intersection separates list items |
- |/ slat |
- |\ backslat |
- |@ whirlpool |
- |-\b' hookworm |
- |^ shark (or simply sharkfin) |
- |#\b*\b[] blotch |
- +--------------------------------------------------------------------------+
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- - 41 -
-
-
- | |
- +--------------------------------------------------------------------------+
- |C\b.haracter spot Name identiU\bfs\bye |
- |\b(\b1i\b6\b:f\b-ba\bin\bty)\bvariabl\bte\bwo-spot identify |
- |\b32\b,-bit variabl\bte\bail identify |
- |\b16\b;-bit array hybrid identify |
- |\b32\b#-bit array mesh identify |
- |\bco\b=\b'\b`\b!nstant h\bs\bb\bwa\bp\ba\bol\ba\bc\bwf\br\bk-\bk\bsm\bpe\bas\brh\bk g\ber\bqo\buu\bip\bve\bar\blent |
- |\bto\b? spark-spotwhat unary |
- |\blo\b"\b"\b.gical XOR r\bra\bab\bbb\bbi\bit\bt-ears g\ber\bqo\buu\bip\bve\bar\blent |
- |\bto\b|\b% ears-spot s\bdp\boi\buk\bbe\ble-oh-seven percentage |
- |\bqu\b-alifier worm used with |
- |\ban\b<gles angle used with |
- |\bwo\b>\b(rms r\bwi\bag\bxht angle precedes |
- |\bli\b)ne label wane follows |
- |\bli\b[\b]\b{\b}\b*ne label U\bU\be\bb\bsm\br\bpt\bt\bb\ba\blu\bu\br\bc\bar\br\ba\be\btn\bn\bc\ble\beb\btack flags |
- |\bin\b&valid statem\bae\bmn\bpt\bes\brsand 10 unary |
- |\blo\bVgical AND V (or book) unary |
- |\blo\bV\b-gical OR bookworm (universal qualifier) unary |
- |\blo\b$gical XOR (I\bbN\biT\bgERCA\bmL\bo-\bn7\be2\by) binary |
- |\bmi\bc\b/ngle change binary |
- |\bmi\b~ngle (INTERC\bsA\bqL\bi-\bg7\bg2\bl)\be binary |
- |\bse\b_\b-lect f\bol\bva\bet\brlw\bio\bnr\bem indicates |
- |\b"t\b+imes 1000" intersection separates |
- |\bli\b/\b\\b@st items s\bb\bwl\ba\bha\bc\bit\bk\brs\bll\bpa\bot\bol unary |
- |\blo\b-\b'\b^gical BUT (T\bh\bsr\bo\bhi\bo\baI\bk\brN\bw\bkT\boE\brR\bmC\b(A\boL\br) simply sharkfin) unary |
- +\bl-\bo\b#\b*\b[-\bg\b]-\bi-\bc-\ba-\bl--\bX\bT-\bO\ba-\bR\bb-\bl-\b(\be-\bT\bb-\br\bl\b2-\bi\bo-\bI\bt\b(-\bN\bc\bt-\bT\bh\bo-\bE\bp-\bR-\bC\bv-\bA\bi-\bL\be-\b)\bw-\b)-\b.--\bI-\bN-\bT-\bE-\bR-\bC-\bA-\bL--\bc-\bh-\ba-\br-\ba-\bc-\bt-\be-\br--\bs-\be-\bt-\b.------------------------+
-
-
-
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-
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-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- ____________________
-
- 10.Got any better ideas?
-
-
-
-
-
-
-
- - 42 -
-
-
-
- T\bTO\bON\bNS\bSI\bIL\bL B\bB
-
-
- N\bNO\bOT\bTE\bES\bS O\bON\bN T\bTH\bHE\bE A\bAT\bTA\bAR\bRI\bI I\bIM\bMP\bPL\bLE\bEM\bME\bEN\bNT\bTA\bAT\bTI\bIO\bON\bN
-
-
-
-
- The Atari implementation of INTERCAL differs from the
- original Princeton version primarily in the use of ASCII
- rather than EBCDIC. Since there is no "change" sign (c\b/) in
- ASCII, we have substituted the "big money" ($) as the mingle
- operator. We feel that this correctly represents the
- increasing cost of software in relation to hardware.
- (Consider that in 1970 one could get RUNOFF for free, to run
- on a $20K machine, whereas today a not quite as powerful
- formatter costs $99 and runs on a $75 machine.) We also feel
- that there should be no defensible contention that INTERCAL
- has any sense. Also, since overpunches are difficult to
- read on the average VDT, the exclusive-or operator may be
- written ?. This correctly expresses the average person's
- reaction on first encountering exclusive-or, especially on a
- PDP-11. Note that in both of these cases, the over-punched
- symbol may also be used if one is masochistic, or concerned
- with portability to the Princeton compiler. The correct
- over-punch for "change" is "c<backspace>/" and the correct
- over-punch for V\b- is "V<backspace>-". These codes will be
- properly printed if you have a proper printer, and the
- corresponding EBCDIC code will be produced by the /IBM
- option on the LIST command.
-
-
-
-
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projects / intercal.git / commitdiff