diff options
| -rw-r--r-- | hash.c | 13 | ||||
| -rw-r--r-- | hash.h | 1 | ||||
| -rw-r--r-- | txr.1 | 21 |
3 files changed, 35 insertions, 0 deletions
@@ -754,6 +754,18 @@ val remhash(val hash, val key) return nil; } +val clearhash(val hash) +{ + struct hash *h = coerce(struct hash *, cobj_handle(hash, hash_s)); + val mod = num_fast(256); + val table = vector(mod, nil); + cnum oldcount = h->count; + h->modulus = c_num(mod); + h->count = 0; + h->table = table; + return oldcount ? num(oldcount) : nil; +} + val hash_count(val hash) { struct hash *h = coerce(struct hash *, cobj_handle(hash, hash_s)); @@ -1374,6 +1386,7 @@ void hash_init(void) reg_fun(intern(lit("sethash"), user_package), func_n3(sethash)); reg_fun(intern(lit("pushhash"), user_package), func_n3(pushhash)); reg_fun(intern(lit("remhash"), user_package), func_n2(remhash)); + reg_fun(intern(lit("clearhash"), user_package), func_n1(clearhash)); reg_fun(intern(lit("hash-count"), user_package), func_n1(hash_count)); reg_fun(intern(lit("get-hash-userdata"), user_package), ghu); reg_fun(intern(lit("hash-userdata"), user_package), ghu); @@ -39,6 +39,7 @@ val gethash_f(val hash, val key, loc found); val sethash(val hash, val key, val value); val pushhash(val hash, val key, val value); val remhash(val hash, val key); +val clearhash(val hash); val hash_count(val hash); val get_hash_userdata(val hash); val set_hash_userdata(val hash, val data); @@ -34998,6 +34998,27 @@ is returned. Otherwise .code nil is returned. +.coNP Function @ clearhash +.synb +.mets (clearhash << hash ) +.syne +.desc +The +.code clearhash +function removes all keys-value pairs from +.metn hash , +causing it to be empty. + +If +.meta hash +is already empty prior to the operation, then +.codn nil , +is returned. + +Otherwise an integer is returned indicating the number of entries +that were purged from +.metn hash . + .coNP Function @ hash-count .synb .mets (hash-count << hash ) |