diff options
| -rw-r--r-- | eval.c | 1 | ||||
| -rw-r--r-- | lib.c | 63 | ||||
| -rw-r--r-- | lib.h | 1 | ||||
| -rw-r--r-- | stdlib/doc-syms.tl | 5 | ||||
| -rw-r--r-- | txr.1 | 19 |
5 files changed, 86 insertions, 3 deletions
@@ -7150,6 +7150,7 @@ void eval_init(void) reg_fun(intern(lit("rfind-if"), user_package), func_n3o(rfind_if, 2)); reg_fun(intern(lit("find-max"), user_package), func_n3o(find_max, 1)); reg_fun(intern(lit("find-min"), user_package), func_n3o(find_min, 1)); + reg_fun(intern(lit("find-true"), user_package), func_n3o(find_true, 2)); reg_fun(intern(lit("multi-sort"), user_package), func_n3o(multi_sort, 2)); reg_fun(intern(lit("set-diff"), user_package), func_n4o(set_diff, 2)); reg_fun(intern(lit("diff"), user_package), func_n4o(diff, 2)); @@ -10411,6 +10411,69 @@ val find_min(val seq, val testfun, val keyfun) return find_max(seq, default_arg(testfun, less_f), keyfun); } +val find_true(val pred, val seq, val key) +{ + val self = lit("find-true"); + val keyfun = default_arg(key, identity_f); + seq_info_t si = seq_info(seq); + + switch (si.kind) { + case SEQ_NIL: + break; + case SEQ_HASHLIKE: + { + struct hash_iter hi; + val cell; + + hash_iter_init(&hi, si.obj, self); + + while ((cell = hash_iter_next(&hi))) { + val key = funcall1(keyfun, cell); + val res = funcall1(pred, key); + if (res) + return res; + } + + break; + } + case SEQ_LISTLIKE: + { + gc_hint(seq); + + for (seq = z(si.obj); seq; seq = cdr(seq)) { + val elt = car(seq); + val key = funcall1(keyfun, elt); + val res = funcall1(pred, key); + if (res) + return res; + } + + break; + } + case SEQ_VECLIKE: + { + val vec = si.obj; + cnum len = c_fixnum(length(vec), self); + cnum i; + + for (i = 0; i < len; i++) { + val elt = ref(vec, num_fast(i)); + val key = funcall1(keyfun, elt); + val res = funcall1(pred, key); + if (res) + return res; + } + + break; + } + case SEQ_NOTSEQ: + default: + unsup_obj(self, seq); + } + + return nil; +} + val find_if(val pred, val seq, val key) { val self = lit("find-if"); @@ -1150,6 +1150,7 @@ val find_if(val pred, val list, val key); val rfind_if(val pred, val list, val key); val find_max(val seq, val testfun, val keyfun); val find_min(val seq, val testfun, val keyfun); +val find_true(val pred, val list, val keyfun); val posqual(val obj, val list); val rposqual(val obj, val list); val posql(val obj, val list); diff --git a/stdlib/doc-syms.tl b/stdlib/doc-syms.tl index 90d8bd07..13361afc 100644 --- a/stdlib/doc-syms.tl +++ b/stdlib/doc-syms.tl @@ -729,16 +729,17 @@ ("filter-string-tree" "N-00C9EEB0") ("finalize" "N-01230613") ("finally" "D-0079") - ("find" "N-005431FF") + ("find" "N-00C9DFF6") ("find-frame" "N-02B97226") ("find-frames" "N-02B97226") - ("find-if" "N-005431FF") + ("find-if" "N-00C9DFF6") ("find-max" "N-02BB4231") ("find-min" "N-02BB4231") ("find-package" "N-0250826D") ("find-struct-type" "N-01E5EEA7") ("find-symbol" "N-01EA8B50") ("find-symbol-fb" "N-01EA8B50") + ("find-true" "N-00C9DFF6") ("first" "N-02D60463") ("fixnum-max" "N-02A6CE24") ("fixnum-min" "N-02A6CE24") @@ -33403,10 +33403,11 @@ is returned. (partition* "abcd" '(0 1 2 3)) -> nil .brev -.coNP Functions @ find and @ find-if +.coNP Functions @, find @ find-if and @ find-true .synb .mets (find < key < sequence >> [ testfun <> [ keyfun ]]) .mets (find-if < predfun >> { sequence | << hash } <> [ keyfun ]) +.mets (find-true < predfun >> { sequence | << hash } <> [ keyfun ]) .syne .desc The @@ -33415,6 +33416,12 @@ and .code find-if functions search through a sequence for an item which matches a key, or satisfies a predicate function, respectively. +The +.code find-true +function is a variant of +.code find-if +which returns the value of the predicate function, instead +of the item. The .meta keyfun @@ -33475,6 +33482,16 @@ of which are the hash values. If the caller doesn't specify a .meta keyfun then these cells are taken as their keys. +The +.code find-true +funtion's argument conventions and search semantics are identical to those of +.codn find-if , +but the return value is different. Instead of returning the found item, +.code find-true +returns the value which +.meta predfun +returned for the found item's key. + .coNP Functions @ rfind and @ rfind-if .synb .mets (rfind < key < sequence >> [ testfun <> [ keyfun ]]) |