From fc4598df1e3bfbe9450b584cfa85e919b458f170 Mon Sep 17 00:00:00 2001
From: "Eric S. Raymond" <esr@thyrsus.com>
Date: Mon, 14 Nov 1994 17:19:36 +0000
Subject: [PATCH] Allow bison or flex to be used.

---
 Makefile | 10 +++++++++-
 cupl.l   | 11 ++++++++++-
 cupl.y   |  7 ++++++-
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 409fc4a..8e95bcf 100644
--- a/Makefile
+++ b/Makefile
@@ -11,8 +11,16 @@ MODULES = main.o grammar.o lexer.o interpret.o tokdump.o execute.o monitor.o
 cupl: $(MODULES)
 	$(CC) $(MODULES) -lm -o cupl
 
+# You can use either lex or flex
+#LEX = lex
+LEX = flex
+
+# You can use either bison or yacc
+#YACC = yacc
+YACC = bison -y
+
 lexer.c: cupl.l
-	lex $(LFLAGS) cupl.l
+	$(LEX) $(LFLAGS) cupl.l
 	mv lex.yy.c lexer.c
 
 grammar.c tokens.h y.output: cupl.y
diff --git a/cupl.l b/cupl.l
index 1ef53f0..031d5cd 100644
--- a/cupl.l
+++ b/cupl.l
@@ -16,6 +16,10 @@ lvar *idlist;
 static node *intern_number(char *);
 static node *intern_identifier(char *);
 static node *intern_string(char *);
+
+#ifdef FLEX_SCANNER
+int yylineno;
+#endif /* FLEX_SCANNER */
 %}
 
 D	[0-9][0-9]*
@@ -83,7 +87,12 @@ WRITE		{return(WRITE);}
 "**"		{return(POWER);}
 [+*/().,=-]	{return(yytext[0]);}
 
-[ \t\n]		;
+[ \t]		;
+\n		{
+#ifdef FLEX_SCANNER
+			yylineno++;
+#endif /* FLEX_SCANNER */
+		}
 
 %%
 
diff --git a/cupl.y b/cupl.y
index 4b2dde9..fa599e9 100644
--- a/cupl.y
+++ b/cupl.y
@@ -27,6 +27,12 @@ author first.
 #ifdef PARSEDEBUG
 static int statement_count;
 #endif /* PARSEDEBUG */
+
+#include "cupl.h"
+
+#ifdef YYBISON
+int yydebug;
+#endif /* YYBISON */
 %}
 
 %start program
@@ -269,7 +275,6 @@ subscr	:    IDENTIFIER '(' expr ')'
 		{$$ = cons(ISLICE, $1, $5);}
 	;
 %%
-#include "cupl.h"
 
 node *cons(op, left, right)
 /* make a cons for a binary operation */
-- 
2.43.0