[[tags: egg]]
[[toc:]]
== binary-search
A straightforward implementation of [[http://en.wikipedia.org/wiki/Binary_search|binary search]].
=== Usage
(binary-search SEQUENCE PROC)
Performs a binary search in {{SEQUENCE}}, which should be a sorted
list or vector. {{PROC}} is called to compare items in the sequence,
should accept a single argument and return an exact integer: zero if the
searched value is equal to the current item, negative if the searched
value is ''less'' than the current item, and positive otherwise.
Returns the index of the found value or {{#f}} otherwise.
{{SEQUENCE}} may also be an exact integer - in this case the search is
performed on an /abstract/ sequence and {{PROC}} is called with the
current index into the abstract sequence. This may be useful if you
just want to iterate over the {{O(log n)}} steps needed to locate a
value in some particular range.
=== Author
The CHICKEN Team
=== License
Copyright (c) 2014, The CHICKEN Team
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the authors may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
=== Version History
; 1.0 : Extracted from {{data-structures}} core library unit and released as an egg.