commit adc5c4e7b834c456ffaabec1ad1e4758d9592dd4
parent a0a2210693fa089417ca5b674384d4387f2e4ae4
Author: Ed van Bruggen <edvb@uw.edu>
Date: Thu, 15 Mar 2018 23:32:26 -0700
Clean up hash_extend functions
Rename hash_extendh to hash_merge. Fix hash_merge from casueing a
segmentation fault on empty hash items
Diffstat:
| tisp.c | | | 36 | ++++++++++++++---------------------- |
1 file changed, 14 insertions(+), 22 deletions(-)
diff --git a/tisp.c b/tisp.c
@@ -91,7 +91,7 @@ struct Val {
/* functions */
static void hash_add(Hash ht, char *key, Val val);
static void hash_extend(Hash ht, Val args, Val vals);
-static void hash_extendh(Hash ht, Hash ht2);
+static void hash_merge(Hash ht, Hash ht2);
Val read_val(Str str);
Val read_list(Str str);
@@ -204,40 +204,32 @@ hash_add(Hash ht, char *key, Val val)
}
}
+/* add each binding args[i] -> vals[i] */
+/* args and vals are both scheme lists */
static void
hash_extend(Hash ht, Val args, Val vals)
{
- // add each binding args[i] -> vals[i]
- // args and vals are both scheme lists
-
Val arg, val;
- while (!nilp(args) && !nilp(vals)) {
+ for (; !nilp(args) && !nilp(vals); args = cdr(args), vals = cdr(vals)) {
arg = car(args);
val = car(vals);
- args = cdr(args);
- vals = cdr(vals);
- if (arg->t != SYMBOL) {
- fprintf(stderr, "Error in hash_extend: Argument not a symbol.");
- exit(1);
- }
+ if (arg->t != SYMBOL)
+ die(1, "%s: hash_extend: Argument not a symbol", argv0);
hash_add(ht, arg->v.s, val);
}
}
+/* add everything from ht2 into ht */
static void
-hash_extendh(Hash ht, Hash ht2)
+hash_merge(Hash ht, Hash ht2)
{
- // add everything from ht2 into ht
-
int i;
- while (ht2) {
- for (i = 0; i < ht2->cap; i++) {
- hash_add(ht, ht2->items[i].key, ht2->items[i].val);
- }
- ht2 = ht2->next;
- }
+ for (; ht2; ht2 = ht2->next)
+ for (i = 0; i < ht2->cap; i++)
+ if (ht2->items[i].key)
+ hash_add(ht, ht2->items[i].key, ht2->items[i].val);
}
Val
@@ -454,9 +446,9 @@ tisp_trampoline(Hash env, Val v, int *continu)
*continu = 0;
return (*f->v.pr)(env, args);
case FUNCTION:
- // tail call into the function body with the extended env
+ /* tail call into the function body with the extended env */
hash_extend(env, f->v.f.args, args);
- hash_extendh(env, f->v.f.env);
+ hash_merge(env, f->v.f.env);
*continu = 1;
return f->v.f.body;
default:
