enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Comparison of regular expression engines - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_regular...

    The primary regex crate does not allow look-around expressions. There is an Oniguruma binding called onig that does. SAP ABAP: SAP.com: Proprietary: Tcl: tcl.tk: Tcl/Tk License (BSD-style) Tcl library doubles as a regular expression library. Wolfram Language: Wolfram Research: Proprietary: usable for free on a limited scale on the Wolfram ...

  3. Regular expression - Wikipedia

    en.wikipedia.org/wiki/Regular_expression

    A regular expression (shortened as regex or regexp), [1] sometimes referred to as rational expression, [2] [3] is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings , or for input validation .

  4. Perl Compatible Regular Expressions - Wikipedia

    en.wikipedia.org/wiki/Perl_Compatible_Regular...

    For example, the set of characters matched by \w (word characters) is expanded to include letters and accented letters as defined by Unicode properties. Such matching is slower than the normal (ASCII-only) non-UCP alternative. Note that the UCP option requires the library to have been built to include Unicode support (this is the default for ...

  5. Comparison of programming languages (string functions)

    en.wikipedia.org/wiki/Comparison_of_programming...

    find_character(string,char) returns integer Description Returns the position of the start of the first occurrence of the character char in string. If the character is not found most of these routines return an invalid index value – -1 where indexes are 0-based, 0 where they are 1-based – or some value to be interpreted as Boolean FALSE.

  6. Boyer–Moore string-search algorithm - Wikipedia

    en.wikipedia.org/wiki/Boyer–Moore_string-search...

    If the characters do not match, there is no need to continue searching backwards along the text. If the character in the text does not match any of the characters in the pattern, then the next character in the text to check is located m characters farther along the text, where m is the length of the pattern.

  7. Levenshtein distance - Wikipedia

    en.wikipedia.org/wiki/Levenshtein_distance

    A more efficient method would never repeat the same distance calculation. For example, the Levenshtein distance of all possible suffixes might be stored in an array , where [] [] is the distance between the last characters of string s and the last characters of string t. The table is easy to construct one row at a time starting with row 0. When ...

  8. Parsing expression grammar - Wikipedia

    en.wikipedia.org/wiki/Parsing_expression_grammar

    A parsing expression is a kind of pattern that each string may either match or not match.In case of a match, there is a unique prefix of the string (which may be the whole string, the empty string, or something in between) which has been consumed by the parsing expression; this prefix is what one would usually think of as having matched the expression.

  9. Thompson's construction - Wikipedia

    en.wikipedia.org/wiki/Thompson's_construction

    In computer science, Thompson's construction algorithm, also called the McNaughton–Yamada–Thompson algorithm, [1] is a method of transforming a regular expression into an equivalent nondeterministic finite automaton (NFA). [2] This NFA can be used to match strings against the regular expression.