diff options
Diffstat (limited to 'pod/perlre.pod')
| -rw-r--r-- | pod/perlre.pod | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/pod/perlre.pod b/pod/perlre.pod index 1324642f71..295b6bd518 100644 --- a/pod/perlre.pod +++ b/pod/perlre.pod @@ -297,11 +297,9 @@ first alternative includes everything from the last pattern delimiter the last alternative contains everything from the last "|" to the next pattern delimiter. For this reason, it's common practice to include alternatives in parentheses, to minimize confusion about where they -start and end. Note also that the pattern C<(fee|fie|foe)> differs -from the pattern C<[fee|fie|foe]> in that the former matches "fee", -"fie", or "foe" in the target string, while the latter matches -anything matched by the classes C<[fee]>, C<[fie]>, or C<[foe]> (i.e. -the class C<[feio]>). +start and end. Note however that "|" is interpreted as a literal with +square brackets, so if you write C<[fee|fie|foe]> you're really only +matching C<[feio|]>. Within a pattern, you may designate subpatterns for later reference by enclosing them in parentheses, and you may refer back to the I<n>th @@ -309,7 +307,7 @@ subpattern later in the pattern using the metacharacter \I<n>. Subpatterns are numbered based on the left to right order of their opening parenthesis. Note that a backreference matches whatever actually matched the subpattern in the string being examined, not the -rules for that subpattern. Therefore, C<([0|0x])\d*\s\1\d*> will +rules for that subpattern. Therefore, C<(0|0x)\d*\s\1\d*> will match "0x1234 0x4321",but not "0x1234 01234", since subpattern 1 -actually matched "0x", even though the rule C<[0|0x]> could +actually matched "0x", even though the rule C<0|0x> could potentially match the leading 0 in the second number. |