First hack at working for.

diff --git a/execute.c b/execute.c
index 40509cf73d541fdfa9204b107862362ecdc53492..2d63b6683700427403ed3e3352714a2d0ebb8c00 100644 (file)
--- a/execute.c
+++ b/execute.c
@@ -142,11 +142,25 @@ static void display_return(node *tree, node *left, node *right, value v)
     }
 }
 
+static void cupl_assign(node *to, value from)
+/* assign result of the expression at the cdr to the identifier at the cdr */
+{
+    static value cupl_eval(node *);
+
+    deallocate_value(&(to->syminf->value));
+    to->syminf->value = from;
+    if (to->syminf->watchcount && to->syminf->watchcount--)
+    {
+       eval_write(to);
+       cupl_eol_write();
+    }
+}
+
 static value cupl_eval(node *tree)
 /* recursively evaluate a CUPL parse tree */
 {
     value      leftside, rightside, result, cond;
-    node       *np;
+    node       *np, *iterator;
     int                n;
     jmp_buf    jmpperf;
 
@@ -183,13 +197,7 @@ static value cupl_eval(node *tree)
        return(result);
 
     case LET:
-       deallocate_value(&(tree->car->syminf->value));
-       tree->car->syminf->value = EVAL_WRAP(cupl_eval(tree->cdr));
-       if (tree->car->syminf->watchcount && tree->car->syminf->watchcount--)
-       {
-           eval_write(tree->car);
-           cupl_eol_write();
-       }
+       cupl_assign(tree->car, EVAL_WRAP(cupl_eval(tree->cdr)));
        result.rank = FAIL;
        RETURN_WRAP(tree, tree->car, tree->cdr, result)
        return(result);
@@ -494,8 +502,38 @@ static value cupl_eval(node *tree)
        return(result);
 
     case FOR:
-       /* FIXME: implement FOR */
-       die("FOR is not implemented\n");
+       /* FIXME: this code is not tested yet */
+       iterator = tree->car;
+       if (iterator->type == '=')
+       {
+           for_cdr(np, tree)
+           {
+               result = EVAL_WRAP(cupl_eval(np->car));
+               cupl_assign(iterator->car, result);
+               cupl_eval(tree->cdr);
+           }
+       }
+       else if (iterator->type == ITERATE)
+       {
+           value       v;
+           scalar ds, initial, final, increment;
+
+           initial = EVAL_WRAP(cupl_eval(iterator->cdr->car)).elements[0];
+           iterator = iterator->cdr->cdr;
+           final = EVAL_WRAP(cupl_eval(iterator->car)).elements[0];
+           increment = iterator->cdr ? EVAL_WRAP(cupl_eval(iterator->car)).elements[0] : 1;
+           make_scalar(&v, ds);
+
+           for (ds = initial; ds <= final; ds += increment)
+           {
+               v.elements[0] = ds;
+               cupl_assign(tree->car->car, v);
+               cupl_eval(tree->cdr);
+           }
+           deallocate_value(&v);
+       }
+       else
+           die("unknown iterator in FOR statement\n");
        result.rank = FAIL;
        return(result);