diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 42 |
1 files changed, 41 insertions, 1 deletions
@@ -32451,10 +32451,11 @@ is omitted, then each element itself of is compared to .metn object . -.coNP Functions @, remove-if @, keep-if @ remove-if* and @ keep-if* +.coNP Functions @, remove-if @, keep-if @, separate @ remove-if* and @ keep-if* .synb .mets (remove-if < predicate-function < sequence <> [ key-function ]) .mets (keep-if < predicate-function < sequence <> [ key-function ]) +.mets (separate < predicate-function < sequence <> [ key-function ]) .mets (remove-if* < predicate-function < sequence <> [ key-function ]) .mets (keep-if* < predicate-function < sequence <> [ key-function ]) .syne @@ -32497,6 +32498,45 @@ will delete, and removes those that will preserve. The +.code separate +function combines +.code keep-if +and +.code remove-if +into one, +returning a list of two elements whose +.code car +and +.code cadr +are the result of calling +.code keep-if +and +.codn remove-if , +respectively, +on +.meta sequence +(with the +.meta predicate-function +and +.meta key-function +arguments passed through). +One of the two elements may share substructure with the input sequence, +and may even be the same sequence object if all items are either kept or +removed (in which case the other element will be +.codn nil ). + +Note: the +.code separate +function may be understood in terms of the following reference implementation: + +.verb + (defun separate (pred seq : (keyfun :)) + [(juxt (op keep-if pred @1 keyfun) + (op remove-if pred @1 keyfun)) + seq]) +.brev + +The .code remove-if* and .code keep-if* |