diff options
| -rw-r--r-- | lib.c | 56 | ||||
| -rw-r--r-- | txr.1 | 14 |
2 files changed, 60 insertions, 10 deletions
@@ -8651,20 +8651,58 @@ val find_if(val pred, val seq, val key) return nil; } -val rfind_if(val pred, val list, val key) +val rfind_if(val predi, val seq, val key) { + val keyfun = default_arg(key, identity_f); + seq_info_t si = seq_info(seq); val found = nil; - key = default_arg(key, identity_f); - list = nullify(list); - gc_hint(list); + switch (si.kind) { + case SEQ_NIL: + break; + case SEQ_HASHLIKE: + { + val hiter = hash_begin(si.obj); + val cell; - for (; list; list = cdr(list)) { - val item = car(list); - val subj = funcall1(key, item); + while ((cell = hash_next(hiter))) { + val key = funcall1(keyfun, cell); + if (funcall1(predi, key)) + found = cell; + } - if (funcall1(pred, subj)) - found = item; + 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); + if (funcall1(predi, key)) + found = elt; + } + + break; + } + case SEQ_VECLIKE: + { + val vec = si.obj; + val i = pred(length(vec)); + + for (; plusp(i); i = pred(i)) { + val elt = ref(vec, i); + val key = funcall1(keyfun, elt); + if (funcall1(predi, key)) + return elt; + } + + break; + } + case SEQ_NOTSEQ: + default: + uw_throwf(error_s, lit("rfind-if: unsupported object ~s"), seq, nao); } return found; @@ -27491,7 +27491,7 @@ then these cells are taken as their keys. .coNP Functions @ rfind and @ rfind-if .synb .mets (rfind < key < sequence >> [ testfun <> [ keyfun ]]) -.mets (rfind-if < predfun < sequence <> [ keyfun ]) +.mets (rfind-if < predfun >> { sequence | << hash } <> [ keyfun ]) .syne .desc The @@ -27509,6 +27509,18 @@ in they return the right-most element rather than the leftmost. +In the case of +.code rfind-if +when a +.meta hash +is specified instead of a +.metn sequence , +the function searches through the hash entries in the same order as +.codn find-if , +but finds the last match rather than the first. +Note: hashes are inherently not ordered; the relative order of items in +a hash table can change when other items are inserted or deleted. + .coNP Functions @ find-max and @ find-min .synb .mets (find-max >> { sequence | << hash } >> [ testfun <> [ keyfun ]]) |