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Regex Composer


This essay does not describe an existing computer program, just one that should exist. This essay is about a suggested student project in Java programming. This essay gives a rough overview of how it might work. I have no source, object, specifications, file layouts or anything else useful to implementing this project. Everything I have prepared to help you is right here.

This project outline is not like the artificial, tidy little problems you are spoon-fed in school, when all the facts you need are included, nothing extraneous is mentioned, the answer is fully specified, along with hints to nudge you toward a single expected canonical solution. This project is much more like the real world of messy problems where it is up to you to fully the define the end point, or a series of ever more difficult versions of this project and research the information yourself to solve them.

Everything I have to say to help you with this project is written below. I am not prepared to help you implement it; or give you any additional materials. I have too many other projects of my own.

Though I am a programmer by profession, I don’t do people’s homework for them. That just robs them of an education.

You have my full permission to implement this project in any way you please and to keep all the profits from your endeavour.

Please do not email me about this project without reading the disclaimer above.

Composing Regular Expressions is daunting for anyone but a dedicated geek. This program makes regexes accessible to the masses. There are several ways it could work:
  1. Convert standard wild card expressions with * and ? into regexes.
  2. Fill in the blanks selecting various standard patterns. The program builds a visual tree of what the regex does, with nodes where you can edit parameters. What to select, what to avoid, by check box, or ticking individual chars, or listing strings.
  3. The user gives examples of what he wants and does not want to match. The program tries to deduce a regex that fits the examples. Then it generates examples that would fit and not fit. The user corrects the examples it got wrong and it composes a new regex. Iteratively, you get a regex that is close enough to what you need.
The program might generate either:

Ideally this functionality should be built into the IDE (Integrated Development Environment), perhaps with plug-in.

Regex Debugger
Regex Proofreader
Regex Tidier
Regex Utility

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