Document use of - in a regex char class.

[p5sagit/p5-mst-13.2.git] / pod / perlre.pod

diff --git a/pod/perlre.pod b/pod/perlre.pod
index ed9c533..37434a6 100644 (file)
--- a/pod/perlre.pod
+++ b/pod/perlre.pod
@@ -515,7 +515,11 @@ in C<[]>, which will match any one of the characters in the list.  If the
 first character after the "[" is "^", the class matches any character not
 in the list.  Within a list, the "-" character is used to specify a
 range, so that C<a-z> represents all the characters between "a" and "z",
-inclusive.
+inclusive.  If you want "-" itself to be a member of a class, put it
+at the start or end of the list, or escape it with a backslash.  (The
+following all specify the same class of three characters: C<[-az]>,
+C<[az-]>, and C<[a\-z]>.  All are different from C<[a-z]>, which
+specifies a class containing twenty-six characters.)
 
 Characters may be specified using a metacharacter syntax much like that
 used in C: "\n" matches a newline, "\t" a tab, "\r" a carriage return,
@@ -573,3 +577,7 @@ You can't disambiguate that by saying C<\{1}000>, whereas you can fix it with
 C<${1}000>.  Basically, the operation of interpolation should not be confused
 with the operation of matching a backreference.  Certainly they mean two
 different things on the I<left> side of the C<s///>.
+
+=head2 SEE ALSO
+
+"Mastering Regular Expressions" (see L<perlbook>) by Jeffrey Friedl.