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 f881a3b..37434a6 100644 (file)
--- a/pod/perlre.pod
+++ b/pod/perlre.pod
@@ -163,7 +163,7 @@ Perl defines the following zero-width assertions:
     \B Match a non-(word boundary)
     \A Match at only beginning of string
     \Z Match at only end of string (or before newline at the end)
-    \G Match only where previous m//g left off
+    \G Match only where previous m//g left off (works only with /g)
 
 A word boundary (C<\b>) is defined as a spot between two characters that
 has a C<\w> on one side of it and a C<\W> on the other side of it (in
@@ -173,9 +173,10 @@ represents backspace rather than a word boundary.)  The C<\A> and C<\Z> are
 just like "^" and "$" except that they won't match multiple times when the
 C</m> modifier is used, while "^" and "$" will match at every internal line
 boundary.  To match the actual end of the string, not ignoring newline,
-you can use C<\Z(?!\n)>.  The C<\G> assertion can be used to mix global
-matches (using C<m//g>) and non-global ones, as described in
+you can use C<\Z(?!\n)>.  The C<\G> assertion can be used to chain global
+matches (using C<m//g>), as described in
 L<perlop/"Regexp Quote-Like Operators">.
+
 It is also useful when writing C<lex>-like scanners, when you have several
 regexps which you want to match against consequent substrings of your
 string, see the previous reference.
@@ -514,7 +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,
@@ -572,3 +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.