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Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 62 |
1 files changed, 62 insertions, 0 deletions
@@ -7025,6 +7025,68 @@ transformed to an argument to <predicate-function>. If this argument is omitted then the predicate function is applied to the elements directly, a behavior which is identical to <key-function> being (fun identity). +.SS Functions posqual, posql and posq + +.TP +Syntax: + + (posq <object> <list>) + (posql <object> <list>) + (posqual <object> <list>) + +.TP +Description + +The posq, posql and posqual functions return the zero-based position of the +first item in <list> which is, respectively, eq, eql or equal to <object>. + +.SS Functions posqual, posql and posq + +.TP +Syntax: + + (posq <object> <list>) + (posql <object> <list>) + (posqual <object> <list>) + +.TP +Description + +The posq, posql and posqual functions return the zero-based position of the +first item in <list> which is, respectively, eq, eql or equal to <object>. + +.SS Functions pos and pos-if + +.TP +Syntax: + + (pos <key> <list> [<testfun> [<keyfun>]]) + (pos-if <predfun> <list> [<keyfun>]) + +.TP +Description: + +The pos and pos-if functions search through a list for an item which +matches a key, or satisfies a predicate function, respectively. +They return the zero based position of the matching item. + +The keyfun argument specifies a function which is applied to the elements +of the list to produce the comparison key. If this argument is omitted, +then the untransformed elements of the list themselves are searched. + +The pos function's testfun argument specifies the test function which +is used to compare the comparison keys from the list to the search key. +If this argument is omitted, then the equal function is used. +The position of the first element from the list whose comparison key (as +retrieved by the key function) matches the search (under the test function) is +returned. If no such element is found, nil is returned. + +The pos-if function's predfun argument specifies a predicate function +which is applied to the successive comparison keys pulled from the list +by applying the key function to successive elements. The position of +the first element for which the predicate function yields true is returned. If +no such element is found, nil is returned. + .SS Function tree-find .TP |