Match pattern and grab argument value using elisp regex returns nil

Question

This is my code statement

var myStr = require('ssh2')

and my elisp regex must return the arg value iff the statement has a require func invocation.

 (let ((s "var myStr = require('ssh2')"))
   (if (string-match "'require(\\([^']+\\)'" s)
       (match-string 1 s)))

this returns nil, however? what makes my regex a mess, someone?

score 2 · Accepted Answer · edited May 23 '17 at 12:20

2

How about?:

"require\(\\(?:'\\(.*\\)'\\)\)"

If you haven't already played around with M-x re-builder RET, you'll enjoy it.

Here is a link to one of my favorite threads regarding a noncapturing group:

edited May 23 '17 at 12:20

Community

answered Jan 18 '15 at 04:42

lawlist

it worked... but this pattern, "require\\(\\(?:'\\(.*\\)'\\)\)" returned nil... the change i have made is put double slashes in the place of single slashes because somewhere i read in elisp, all escapes must be done twice... – Jan 18 '15 at 04:44
I believe **literal** parentheses are **single**-escaped. Re-builder will fail if **literal** parentheses are **double**-escaped. Parentheses that are for *grouping*, are **double**-escaped. Your example contains an opening *literal* parentheses and a closing *literal* parentheses. – lawlist Jan 18 '15 at 04:48

1 Answers1