28 lines
1.4 KiB
Text
28 lines
1.4 KiB
Text
This module exports two functions, nsort and ncmp; they are used in implementing
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my idea of a "natural sorting" algorithm. Under natural sorting, numeric
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substrings are compared numerically, and other word-characters are compared
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lexically.
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This is the way I define natural sorting:
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* Non-numeric word-character substrings are sorted lexically,
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case-insensitively: "Foo" comes between "fish" and "fowl".
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* Numeric substrings are sorted numerically: "100" comes after "20",
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not before.
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* \W substrings (neither words-characters nor digits) are ignored. Our use
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* of \w, \d, \D, and \W is locale-sensitive: Sort::Naturally
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uses a use locale statement.
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* When comparing two strings, where a numeric substring in one place
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is not up against a numeric substring in another, the non-numeric always comes
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first. This is fudged by reading pretending that the lack of a number substring
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has the value -1, like so:
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* The start of a string is exceptional: leading non-\W (non-word,
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non-digit) components are ignored, and numbers come before letters.
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* I define "numeric substring" just as sequences matching m/\d+/ --
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scientific notation, commas, decimals, etc., are not seen. If your data has
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thousands separators in numbers ("20,000 Leagues Under The Sea" or "20.000
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lieues sous les mers"), consider stripping them before feeding them to nsort or
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ncmp.
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Author: Sean M. Burke <sburke@cpan.org>
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WWW: http://search.cpan.org/dist/Sort-Naturally/
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