

Regex Visualization: give it a regex and see the state diagram  - jjguy
http://strfriend.com/

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_delirium
Two other regex-understanding tools I've found useful:

<http://www.regexbuddy.com/>

<http://www.regexio.com/>

~~~
darragjm
My personal favorite:

<http://gskinner.com/RegExr/>

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turbodog
It would be more useful if the state diagram page displayed the original
regex.

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thisrod
I think the ultimate tool for understanding regexps is Russ Cox's notes:

<http://swtch.com/~rsc/regexp/>

When explained well, the big picture of NFAs and DFAs is bog simple. I'm sure
some of the details are messy, but I expect they rarely matter.

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abraham
Visualization of the perfect email regex: <http://goo.gl/p80Ky>

Regex source: [http://fightingforalostcause.net/misc/2006/compare-email-
reg...](http://fightingforalostcause.net/misc/2006/compare-email-regex.php)

~~~
prodigal_erik
Please don't use that to filter real email addresses. The author admitted he
doesn't distinguish between addresses which are actually invalid and those he
merely doesn't think are advisable to use, and it's not clear whether he even
read the RFC 2822 grammar. At a glance, there's only one regex on the page
that makes any effort to handle the valid address "Your Name"@example.com.

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VeXocide
Unfortunately it doesn't allow me to enter the regular expression found here:
<http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html>. It's horrendous I but
would love to see it visualized.

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nerfhammer
The re.DEBUG flag for the python re module is also really useful in this
regard

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k4st
This is nice for visualizing an NFA and the minimized DFA for asome regular
expression (note: regular!!): <http://osteele.com/tools/reanimator/>. The
aforementioned tool also lets you give input and highlights the current states
of each FA.

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dpkendal
Kept giving me errors about unbalanced brackets, but the same regexps work
perfectly as patterns in BBEdit (PCRE) and in Ruby (Onig).

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js4all
This is really helpful. I always struggle with regex expressions when they
reach some complexity.

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handler
awesome. the best would be if you could go in the opposite direction. like if
you could create regular expressions in the image view and have it output the
text version.

this would probably help a lot of people who aren't 'ninjas' like you and me
;?j

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Andys
Was the visualisation done with a free library? Anyone know the name of it?

