Re: regexp character classes not supported?

[Mark H Weaver]

Limbo Peng <address@hidden> writes:

> I'm confused by the result of string-match:
>
> (string-match "[0-9]+" "abc123zzz") ;; this works, giving result: #
> ("abc123zzz" (3 . 6))
> (string-match "\\d+" "abc123zzz") ;; this doesn't work, giving result:
> #f
>
> Why isn't the "\\d+" syntax (character classes) supported?

Regular expression syntax is not standardized, and there are several
different variants.  The "\d" syntax for character classes is a
non-standard perl extension, and is not supported by Guile.

Guile supports the POSIX regexp syntax, whose character classes look
like this:

  (string-match "[[:digit:]]+" "abc123zzz")
  => #("abc123zzz" (3 . 6))

For more information see:

  http://www.gnu.org/software/guile/manual/html_node/Regular-Expressions.html
  http://www.gnu.org/software/emacs/manual/html_node/emacs/Regexps.html
  http://www.gnu.org/software/emacs/manual/html_node/elisp/Char-Classes.html

     Mark