strings: revert caching of hash value.

Research indicates that this is something useful in
languages that abuse strings for implementing symbols.
We have interned symbols.

* lib.h (struct string): Remove hash member.

* lib.c (string_own, string, string_utf8, mkustring,
string_extend, replace_str, chr_str_set): Remove
all initializations and updates of the removed
hash member.

* hash.c (equal_hash): Do not cache string hash value.

1 files changed, 0 insertions, 7 deletions

diff --git a/hash.c b/hash.c
index 2f99a5ce..d71f0e20 100644
--- a/hash.c
+++ b/hash.c
@@ -315,13 +315,6 @@ ucnum equal_hash(val obj, int *count, ucnum seed)
     return equal_hash(obj->c.car, count, seed)
             + equal_hash(obj->c.cdr, count, seed + (CONS << 8));
   case STR:
-#if HAVE_MALLOC_USABLE_SIZE
-    if (seed == 0) {
-      return if3(obj->st.hash != 0,
-                 obj->st.hash,
-                 obj->st.hash = hash_c_str(obj->st.str, 0, count));
-    }
-#endif
     return hash_c_str(obj->st.str, seed, count);
   case CHR:
     return c_ch(obj);