CLHS: Function SEARCH

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Function SEARCH

Syntax:

search sequence-1 sequence-2 `&key` from-end test test-not key start1 start2 end1 end2

=> position

Arguments and Values:

Sequence-1---a sequence.

Sequence-2---a sequence.

from-end---a generalized boolean. The default is false.

test---a designator for a function of two arguments that returns a generalized boolean.

test-not---a designator for a function of two arguments that returns a generalized boolean.

key---a designator for a function of one argument, or nil.

start1, end1---bounding index designators of sequence-1. The defaults for start1 and end1 are `0` and nil, respectively.

start2, end2---bounding index designators of sequence-2. The defaults for start2 and end2 are `0` and nil, respectively.

position---a bounding index of sequence-2, or nil.

Description:

Searches sequence-2 for a subsequence that matches sequence-1.

The implementation may choose to search sequence-2 in any order; there is no guarantee on the number of times the test is made. For example, when start-end is true, the sequence might actually be searched from left to right instead of from right to left (but in either case would return the rightmost matching subsequence). If the search succeeds, search returns the offset into sequence-2 of the first element of the leftmost or rightmost matching subsequence, depending on from-end; otherwise search returns nil.

If from-end is true, the index of the leftmost element of the rightmost matching subsequence is returned.

Examples:

     (search "dog" "it's a dog's life") =>  7
     (search '(0 1) '(2 4 6 1 3 5) :key #'oddp) =>  2

Side Effects: None.

Affected By: None.

Exceptional Situations: None.

See Also:

Section 3.6 (Traversal Rules and Side Effects)

Notes:

The `:test-not` argument is deprecated.

The following X3J13 cleanup issues, not part of the specification, apply to this section:

- TEST-NOT-IF-NOT:FLUSH-ALL
- MAPPING-DESTRUCTIVE-INTERACTION:EXPLICITLY-VAGUE
- RANGE-OF-START-AND-END-PARAMETERS:INTEGER-AND-INTEGER-NIL
- SUBSEQ-OUT-OF-BOUNDS

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