Regexper: Beautiful regexp visualizations • Hacker News Board

Re: Regexper: Beautiful regexp visualizations

#21

Post by hockeybias » Wed, Jan 02, 2013, 4:02 PM UTC

knowtheory wrote: post #3

Neither beautiful nor a visualization really. For the uninitiated, there's an isomorphic relationship between regular expressions (not PCREs which are way more complicated) and finite state automata proving that if you have a regexp you can generate a FSA for it, and visa versa. What we have here is a system that generates a graph of the finite state automaton for any given regular expression. Neat project, misleadin…

Huh. I wonder if it could handle ^Snarky\s(ass)?\s(Know\sIt\sall)?comment

Re: Regexper: Beautiful regexp visualizations

#22

Post by k3n » Wed, Jan 02, 2013, 4:15 PM UTC

jontro wrote: post #13

The following valid js regexp gives a server error: ^/([^/]+)[/]?(_((site)?(edit|show|manager))(/|$))?([\s\S]*)

  [\s\S]*

Doesn't this match every possible character, 0 to infinity times?

Re: Regexper: Beautiful regexp visualizations

#23

Post by solox3 » Wed, Jan 02, 2013, 4:22 PM UTC

jontro wrote: post #13

The following valid js regexp gives a server error: ^/([^/]+)[/]?(_((site)?(edit|show|manager))(/|$))?([\s\S]*)

Looks like they reject any long regex, including the one on http://stackoverflow.com/questions/46155/validate-email-addr...

Re: Regexper: Beautiful regexp visualizations

#24

Post by annapowellsmith » Wed, Jan 02, 2013, 4:30 PM UTC

Really nice.

Re: Regexper: Beautiful regexp visualizations

#25

Post by gosukiwi » Wed, Jan 02, 2013, 4:37 PM UTC

Wow that's awesome.

Re: Regexper: Beautiful regexp visualizations

#26

Post by morsch » Wed, Jan 02, 2013, 4:46 PM UTC

daGrevis wrote: post #6

Useful. Thanks to this, found a bug in regex I did just today. `/[^0-9^\+]+/` -> `/[^0-9\+]+/` # Thought that I needed to negate "+" as well.

You typically don't need to escape a + inside a character class, either, so /[^0-9+]+/ should work.

Re: Regexper: Beautiful regexp visualizations

#27

Post by TallboyOne » Wed, Jan 02, 2013, 4:48 PM UTC

knowtheory wrote: post #3

Neither beautiful nor a visualization really. For the uninitiated, there's an isomorphic relationship between regular expressions (not PCREs which are way more complicated) and finite state automata proving that if you have a regexp you can generate a FSA for it, and visa versa. What we have here is a system that generates a graph of the finite state automaton for any given regular expression. Neat project, misleadin…

Sorry, but how is that not a visualization? If you're learning regular expressions that's about the best thing you could possibly 'see', even though it doesn't show matches for specific input. And I do actually think it's beautiful. I pasted in a huge regex and was delighted at the output.

Re: Regexper: Beautiful regexp visualizations

#28

Post by [deleted] » Wed, Jan 02, 2013, 4:48 PM UTC

[deleted]

Re: Regexper: Beautiful regexp visualizations

#29

Post by javallone » Wed, Jan 02, 2013, 4:57 PM UTC

Hello, I'm the creator of this (trevmex is one of my co-workers).

I just want to thank everyone for the feedback so far, I am looking into the issues that have been brought up (they'll have to wait until this evening to be fixed though...I have a day job).

Re: Regexper: Beautiful regexp visualizations

#30

Post by pyre » Wed, Jan 02, 2013, 4:58 PM UTC

Breaks for:

  ^([^\W]+)@((?:[a-zA-Z0-9-]+\.)+(?:org|com|net|gov))$

Though this works:

  ^([^\W]+)@([a-zA-Z0-9-]+\.)+(?:org|com|net|gov)$

And it doesn't seem to be the nested groups that are screwing it up because this works:

  ((?:tinker|tailor)+(?:soldier|spy))