Hi Regex-coach,
The example on, "http://www.weitz.de/regex-coach/tutorial18.html", and the Regex Coach Step feature have been helpful, especially in understanding backtracking.
I have a couple minor feature suggestions.
1) Step Tab Keep track of and display the number of times the "Next Step" button is clicked, and append it to the message, like:
19) Sub-match from 2 to 3
2) Info Tab At first glance I thought regex-coach Info pane didn't explain lookahead/lookbehind because of the message, "The selection is invalid", but then I extended the selection. The regular expression I used was, "(?<=\d)(?=(\d\d\d)+(?!\d))". Perhaps the text could provide a suggestion, like: "Did you mean "(?<=\d)"", when a user selects an incomplete expression like "?<=".
When I selected "?:" or "(?:[a]*b|a+ac)", in "(?:[a]*b|a+ac)y", no additional information was provided in the Info Pane for the Group No Capture. Although the Control Tab does represent that, it would be nice if it were reflected in the Info pane too.
3) File menu Add a Clear menu item that would clear the current contents of the Regular expression pane and the Target string pane. If not Clear, maybe Reset or New.
File | Clear (Alt+C) maybe? Or File | Clear | Both (Alt+C) File | Clear | Regular expression pane File | Clear | Target string pane
4) File menu Rather than relying on which pane has the focus, add a specific submenu to "File | Insert File" to position the text, like:
File | Insert File | Regular expression pane File | Insert File | Target string pane
Maybe extend this to Save too.
File | Save | Both File | Save | Regular expression pane File | Save | Target string pane
Very nice. I haven't touched LISP since my college days (I still have my "Learning LISP" handbook :-) and it was fun to see it used.
Thank you.