regex expressions for matching elisp syntactic structures

Faki · 04-18-2022, 04:58 AM

Regarding elisp, are there any regex expressions users would find useful to for matching syntactic structures?

pan64 · 04-18-2022, 05:18 AM

without examples, samples hard to say anything. What are you exactly looking for (I mean what kind of regex do you need)? What do you want to achieve?

Faki · 04-18-2022, 05:59 AM

For instance, I would like a regex expression that matches the following elisp syntactic structures - functions with (defun, (lambda, and (defmacro.

pan64 · 04-18-2022, 08:15 AM

I posted you already: www.regex101.com
You can easily test and check your patterns against your sample text. Do not need to wait for anybody.
What did you try so far? Where did you stuck? Which language do you want to use for it? What is your goal at all? (What should be the outcome?)

Faki · 04-18-2022, 09:21 AM

Am trying to determine the Cyclomatic Complexity on a file or a region of elisp code. By counting the maximum number of nested s-exp.

dugan · 04-18-2022, 01:53 PM

You can't use regex for that, no.

I'd write a program for this. Initialize a variable at zero. Parse the file one character at a time. Each time you see an opening paren, increment the variable. Each time you see a closing paren, decrement it. Keep track of the largest value of the variable, and at the end you'll have the value you want. This will work for valid code.

pan64 · 04-19-2022, 12:20 AM

Quote:

Originally Posted by dugan

You can't use regex for that, no.

I'd write a program for this. Initialize a variable at zero. Parse the file one character at a time. Each time you see an opening parent, increment the variable. Each time you see a closing paren, decrement it. Keep track of the largest value of the variable, and at the end you'll have the value you want. This will work for valid code.

Yes, you should check if the code is syntactically correct and valid, otherwise it is pointless. But I think it is already implemented somewhere, so do not need to do/reinvent it again, just look for an acceptable solution on the net (actually I do not need it so I did not check it).

dugan · 04-19-2022, 09:24 AM

I know of this for Python:

https://pypi.org/project/mccabe/

Faki · 04-19-2022, 06:26 PM

Could something similar to mccabe work on elisp code?