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| author | Kaz Kylheku <kaz@kylheku.com> | 2024-02-09 06:25:11 -0800 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2024-02-09 06:25:11 -0800 |
| commit | 3fb108272f762a4e3afa3f2f925db03b3128c272 (patch) | |
| tree | bcc2195735027e7133ee91249d349dc9be15584c /txr.1 | |
| parent | 25bf01699c2af7f8007404d5a62aeb1d64aee7b0 (diff) | |
| download | txr-3fb108272f762a4e3afa3f2f925db03b3128c272.tar.gz txr-3fb108272f762a4e3afa3f2f925db03b3128c272.tar.bz2 txr-3fb108272f762a4e3afa3f2f925db03b3128c272.zip | |
New function: cons-find.
* eval.c (cons_find): Static function removed; a new one is
implemented in lib.c.
(eval_init): Register cons-find intrinsic.
* lib.c (cons_find_rec): New static function.
(cons_find): New function.
* lib.h (cons_find): Declared.
* tests/012/cons.tl: New file.
* txr.1: Documented cons-find together with tree-find.
Document that tree-find's test-fun argument is optional,
defaulting to equal.
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 48 |
1 files changed, 38 insertions, 10 deletions
@@ -23313,14 +23313,17 @@ infinite lazy structure. --> (a b c d e f g nil z nil h) .brev -.coNP Function @ tree-find +.coNP Functions @ tree-find and @ cons-find .synb -.mets (tree-find < obj < tree << test-function ) +.mets (tree-find < obj < tree <> [ test-function ]) +.mets (cons-find < obj < tree <> [ test-function ]) .syne .desc The .code tree-find -function searches +and +.code cons-find +function search .meta tree for an occurrence of .metn obj . @@ -23338,9 +23341,14 @@ arguments, and has conventions similar to .code eql or .codn equal . +If an argument is omitted, the default function is +.codn equal . +Under both .code tree-find -works as follows. If +and +.codn cons-find , +if .meta tree is equivalent to .meta obj @@ -23348,13 +23356,17 @@ under .metn test-function , then .code t -is returned to announce a successful finding. -If this test fails, and -.meta tree -is an atom, +is returned to announce a successful finding. Next, if the mismatched +.meta obj +is an atom, both functions return .code nil -is returned immediately to -indicate that the find failed. Otherwise, +to indicate that the search failed. + +If none of the above cases occur, the semantics of the functions diverge, as +follows. + +In the case of +.codn tree-find , .meta tree is taken to be a proper list, and @@ -23369,6 +23381,22 @@ which returns a .cod2 non- nil value. +In the case of +.codn cons-find , +.meta tree +is taken to be +.codn cons -cell-based +tree structure. The +.code cons-find +function is recursively applied to the +.code car +and +.code cdr +fields of +.metn tree . +Thus a match may be found in any position in the structure, including the +dotted position of a list. + .coNP Functions @, memq @ memql and @ memqual .synb .mets (memq < object << list ) |