perl-String-Approx

Perl extension for approximate matching (fuzzy matching)

String::Approx lets you match and substitute strings approximately. With this you can emulate errors: typing errorrs, speling errors, closely related vocabularies (colour color), genetic mutations (GAG ACT), abbreviations (McScot, MacScot). NOTE: String::Approx suits the task of *string matching*, not *string comparison*, and it works for *strings*, not for *text*. If you want to compare strings for similarity, you probably just want the Levenshtein edit distance (explained below), the Text::Levenshtein and Text::LevenshteinXS modules in CPAN. See also Text::WagnerFischer and Text::PhraseDistance. (There are functions for this in String::Approx, e.g. adist(), but their results sometimes differ from the bare Levenshtein et al.) If you want to compare things like text or source code, consisting of *words* or *tokens* and *phrases* and *sentences*, or *expressions* and *statements*, you should probably use some other tool than String::Approx, like for example the standard UNIX diff(1) tool, or the Algorithm::Diff module from CPAN. The measure of *approximateness* is the _Levenshtein edit distance_. It is the total number of "edits": insertions, word world deletions, monkey money and substitutions sun fun required to transform a string to another string. For example, to transform _"lead"_ into _"gold"_, you need three edits: lead gead goad gold The edit distance of "lead" and "gold" is therefore three, or 75%. *String::Approx* uses the Levenshtein edit distance as its measure, but String::Approx is not well-suited for comparing strings of different length, in other words, if you want a "fuzzy eq", see above. String::Approx is more like regular expressions or index(), it finds substrings that are close matches.>