from Hacker News

Ask HN: List of words – List of regexes tool?

by e7mac on 12/21/14, 11:39 AM with 5 comments

Does anyone know of a tool that would input a list of strings and output a list of regexes that match the strings? An intelligent regex pattern matcher ? If not, what do you think about building something like this?

  • by _jomo on 12/21/14, 2:09 PM

    There is this insane email validating RegEx [0]. The page says:

    > I did not write this regular expression by hand. It is generated by the Perl module by concatenating a simpler set of regular expressions that relate directly to the grammar defined in the RFC.

    There's also the famous xkcd Regex Golf [1]. Peter Norvig writes:

    >So that got me thinking: can I come up with an algorithm to find a short regex that matches the winners and not the losers?

    And he described his steps to create a RegEx using a list of words that must be matched and those that must not be matched [2]

    [0]: http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html

    [1]: https://xkcd.com/1313/

    [2]: http://nbviewer.ipython.org/url/norvig.com/ipython/xkcd1313....

  • by alansammarone on 12/21/14, 1:06 PM

    Well, this is somewhat vague. There's more than one way of matching any string - you'd have to be more specific about what exact form you want your regexes to have.