Warn about the likes of "[:alnum:]" in regexps

* doc/lispref/searching.texi (Char Classes): Warn about erroneous
usage of named character classes.  Suggested by Stephen Leake
<stephen_leake@stephe-leake.org>.
This commit is contained in:
Eli Zaretskii 2020-02-22 11:07:42 +02:00
parent 0273f261a7
commit 2aed279be1

View file

@ -582,8 +582,13 @@ an unquoted @samp{[} is special again and a @samp{]} not.
@cindex alpha character class, regexp
@cindex xdigit character class, regexp
Here is a table of the classes you can use in a character alternative,
and what they mean:
Below is a table of the classes you can use in a character
alternative, and what they mean. Note that the @samp{[} and @samp{]}
characters that enclose the class name are part of the name, so a
regular expression using these classes needs one more pair of
brackets. For example, a regular expression matching a sequence of
one or more letters and digits would be @samp{[[:alnum:]]+}, not
@samp{[:alnum:]+}.
@table @samp
@item [:ascii:]