rpayanm / regexpal Goto Github PK

A real-time regex explanation tree would be helpful for many reasons and
different types of users.

For n00bs, they can enter a regex and read out an explanation of how it
works in plain text, or print it out as documentation.

For intermediate to advanced users, it would provide a way for RegexBuddy
to provide warnings about cross-browser inconsistency and other types of
issues, as well as feedback about exactly why certain parts of their regex
are highlighted as errors or in a way they did not expect (e.g. with the
whole octal/backreference debacle).

My idea about the interface is that the subject text area could be split in
two, with the regex field on top across the entire UI, the explanation tree
on the left, and the subject text field on the right.

The tree could possibly be implemented using the Ext tree control, in which
case it might be best to re-implement the entire site using Ext. Other UI
solutions should be considered as well.

If the UI is split into match / replace modes, this would only be available
in match mode. Possibly model the feature and any variations on the basic
idea after RegexBuddy's implementations.

RegexPal's regex parser (used for the syntax highlighting) currently does
nothing more than build the HTML for syntax highlighting. No knowledge of
the regex object is preserved beyond what is needed for the remaining
parsing steps.

Instead, the parser should build a complete representation of the regex as
an object, which can then not only be used to construct the HTML for syntax
highlighting, but also reused for additional features like a real-time
regex explanation tree.

What steps will reproduce the problem?
1. Enter a regexp with a named group (e.g. "(?P<test>.*)"
2.
3.

What is the expected output? What do you see instead?
Expected the group names to at the least be ignored. Instead it breaks the 
regexp

What version of the product are you using? On what operating system?
http://regexpal.com/, Chromium browser, Linux

Please provide any additional information below.
This would be a nice feature to add, since it would ease debugging of 
production regexp's with named groups.
Also, have to say i love regexpal. Nice work!

The current regex syntax and match highlighting system of using <pre>
elements underneath <textarea> elements to contain the highlighting (paired
with a container whose scrollbars are used for seemless scrolling) is very
fast but unfortunately too brittle / quirky / buggy to work well across all
A-grade browsers. A more traditional contentEditable / designMode -based
highlighting system might be a pain to set up and will almost certainly be
slower, but it would be more flexible and help to get rid of several
lingering bugs.

I'd like to see the amount of time the regex engine spent processing my test 
regex on the test text. it doesn't need to be anything precise, just a means of 
comparing the performance of one regular expression in relation to another. 
Perhaps it could be displayed in the yellow bar in bold.

Something like this,

Execution Time : (~12ms for 100 runs) 

A replacement string field should be added, which will possibly not be
shown until the user switches into replacement mode. Special replacement
tokens such as $n should be syntax highlighted. Another field below the
subject text field can display the subject text with all substitutions
made, with the substitutions highlighted.

What steps will reproduce the problem?
1. Type anything to match in the match textfield - but leave the first row blank
2. Enter regexp to match (e.g "."
3.

What is the expected output? What do you see instead?
The matches are highlighted on the row above the match

What version of the product are you using? On what operating system?
http://regexpal.com/, Chromium browser, linux

Please provide any additional information below.

Other online RegEx testers have a replace function. A replace function
consists of:
- a second input field for the replace pattern
- a second output field for the output of the replace

See e.g. http://www.myregextester.com/ for an example of the replace
functionality.