Emacs Regex vs Regex in Python, JavaScript, Java
Emacs regular expression is different from the regular expression in JavaScript, Python, etc.
Here are practical major differences.
| JavaScript etc | emacs lisp | |
| Capture | "(capture)" | "\\(capture\\)" |
| digit | "\d" | "[0-9]" or "[[:digit:]]" † |
| word | "\w" | "[_A-Za-z0-9]" or "[[:word:]]" † |
| whitespace | "\s" | "[ \n\t]" or "[[:space:]]" † |
† depends on emacs syntax table. Elisp: Regex Named Character Class and Syntax Table