Re: Tell or determine whichever Perl regex group fails

There exists GraphViz::Regex which visualises a regex as a graph.

My idea was to visualise what happens to that graph when an input string is run against the regex. And then find unvisited or failed nodes. Sorry, that's a rough sketch. Whatever the way, I don't know how to do that. BUT! there is re_graph.pl which claims to not only visualise a regex but also visualise it when run against some input, see the example parsing perl comments. The author is Steve Oualline. Unfortunately I did not manage to get that example to work.

Update: along the lines of the above rough sketch I found (again I think?) this online regex visualiser https://blog.robertelder.org/regular-expression-visualizer/ which shows that it is visible. Anonymous Monk has a way to conveniently extract all the info from running the regex against some input: Re: Tell or determine whichever Perl regex group fails

bw, bliako

Comment on Re: Tell or determine whichever Perl regex group fails

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Re^2: Tell or determine whichever Perl regex group fails by etj (Priest) on Jan 04, 2022 at 18:17 UTC
There's also the more recent GraphViz2::Parse::Regexp.	[reply]
Re^3: Tell or determine whichever Perl regex group fails by bliako (Abbot) on Jan 05, 2022 at 17:24 UTC
great! I did not know that. Can GraphViz2::Parse::Regexp be extended in order to update the Graph with the results from running the regex against some input in the way anonymous monk explained Re: Tell or determine whichever Perl regex group fails? Like this for example: https://blog.robertelder.org/regular-expression-visualizer/ .	[reply]
Re^4: Tell or determine whichever Perl regex group fails by etj (Priest) on Jan 06, 2022 at 23:59 UTC
You wouldn't extend this module, because it does what it's supposed to. What you're describing would be achieved by getting the graph object back, then mutating it with further inputs from somewhere, like the regex debugger mentioned elsewhere here.	[reply]