diff options
| -rw-r--r-- | hash.c | 20 | ||||
| -rw-r--r-- | hash.h | 1 | ||||
| -rw-r--r-- | txr.1 | 23 |
3 files changed, 43 insertions, 1 deletions
@@ -29,6 +29,7 @@ #include <stdio.h> #include <stdarg.h> #include <stdlib.h> +#include <string.h> #include <limits.h> #include <signal.h> #include "config.h" @@ -1145,6 +1146,24 @@ val hash_peek(val iter) return hash_iter_peek(hi); } +val hash_reset(val iter, val hash) +{ + val self = lit("hash-reset"); + struct hash_iter *hi = coerce(struct hash_iter *, + cobj_handle(self, iter, hash_iter_s)); + + if (hi->hash) { + struct hash *h = coerce(struct hash *, hash->co.handle); + h->usecount--; + } + + if (hash) + hash_iter_init(hi, hash, self); + else + memset(hi, 0, sizeof hi); + return iter; +} + val maphash(val fun, val hash) { val self = lit("maphash"); @@ -1891,6 +1910,7 @@ void hash_init(void) reg_fun(intern(lit("hash-begin"), user_package), func_n1(hash_begin)); reg_fun(intern(lit("hash-next"), user_package), func_n1(hash_next)); reg_fun(intern(lit("hash-peek"), user_package), func_n1(hash_peek)); + reg_fun(intern(lit("hash-reset"), user_package), func_n2(hash_reset)); reg_fun(intern(lit("set-hash-traversal-limit"), system_package), func_n1(set_hash_traversal_limit)); reg_fun(intern(lit("gen-hash-seed"), user_package), func_n0(gen_hash_seed)); @@ -63,6 +63,7 @@ val hash_iter_peek(struct hash_iter *hi); val hash_begin(val hash); val hash_next(val iter); val hash_peek(val iter); +val hash_reset(val iter, val hash); val hash_eql(val obj); val hash_equal(val obj, val seed); val hashv(struct args *args); @@ -45344,9 +45344,10 @@ applies first, as above. If that is true, and the two hashes have the same number of elements, the result is falsified. -.coNP Functions @, hash-begin @ hash-next and @ hash-peek +.coNP Functions @, hash-begin @, hash-reset @ hash-next and @ hash-peek .synb .mets (hash-begin << hash ) +.mets (hash-reset < hash-iter << hash ) .mets (hash-next << hash-iter ) .mets (hash-peek << hash-iter ) .syne @@ -45359,6 +45360,20 @@ entries in stored in one by one. The +.code hash-reset +function changes the state of an existing iterator, such that it +becomes prepared to retrieve the entries stored in the newly given +.metn hash , +which may be the same one as the previously associated hash. +In addition, +.code hash-reset +may be given a +.meta hash +argument of +.codn nil , +which dissociates it from its hash table. + +The .code hash-next function's .meta hash-iter @@ -45377,6 +45392,12 @@ If no more entries remain to be visited, .code hash-next returns .codn nil . +The +.code hash-next +function also returns +.code nil +if the iterator has been dissociated from a hash table by +.codn hash-reset . The .code hash-peek |