In perl.git, the branch blead has been updated <http://perl5.git.perl.org/perl.git/commitdiff/b3ed409dee4fd31952bdcb9fa77d0e0c4e4516ab?hp=04e5ac63d9ec63668adef6a2f488bbfb22cce7a8>
- Log ----------------------------------------------------------------- commit b3ed409dee4fd31952bdcb9fa77d0e0c4e4516ab Author: Chip Salzenberg <[email protected]> Date: Thu Aug 20 14:37:01 2009 -0700 incremental improvement in ~~ documentation, already in maint-5.10 ----------------------------------------------------------------------- Summary of changes: lib/overload.pm | 5 +++-- pod/perlsyn.pod | 17 ++++++++--------- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/lib/overload.pm b/lib/overload.pm index 7e392d7..7790832 100644 --- a/lib/overload.pm +++ b/lib/overload.pm @@ -451,8 +451,9 @@ This overload was introduced in perl 5.12. =item * I<Matching> -The key C<"~~"> allows you to override the smart matching used by -the switch construct. See L<feature>. +The key C<"~~"> allows you to override the smart matching logic used by +the C<~~> operator and the switch construct (C<given>/C<when>). See +L<perlsyn/switch> and L<feature>. =item * I<Dereferencing> diff --git a/pod/perlsyn.pod b/pod/perlsyn.pod index 9aa8fbb..c7db812 100644 --- a/pod/perlsyn.pod +++ b/pod/perlsyn.pod @@ -568,8 +568,10 @@ is exactly equivalent to when($_ ~~ $foo) -In fact C<when(EXPR)> is treated as an implicit smart match most of the -time. The exceptions are that when EXPR is: +Most of the time, C<when(EXPR)> is treated as an implicit smart match of +C<$_>, i.e. C<$_ ~~ EXPR>. (See L</"Smart matching in detail"> for more +information on smart matching.) But when EXPR is one of the below +exceptional cases, it is used directly as a boolean: =over 4 @@ -640,9 +642,6 @@ for example. C<default> behaves exactly like C<when(1 == 1)>, which is to say that it always matches. -See L</"Smart matching in detail"> for more information -on smart matching. - =head3 Breaking out You can use the C<break> keyword to break out of the enclosing @@ -690,6 +689,10 @@ implicitly dereferences any non-blessed hash or array ref, so the "Hash" and "Array" entries apply in those cases. (For blessed references, the "Object" entries apply.) +Note that the "Matching Code" column is not always an exact rendition. For +example, the smart match operator short-circuits whenever possible, but +C<grep> does not. + $a $b Type of Match Implied Matching Code ====== ===== ===================== ============= Any undef undefined !defined $a @@ -729,10 +732,6 @@ and "Array" entries apply in those cases. (For blessed references, the 3 - If a circular reference is found, we fall back to referential equality. 4 - either a real number, or a string that looks like a number -The "matching code" doesn't represent the I<real> matching code, -of course: it's just there to explain the intended meaning. Unlike -C<grep>, the smart match operator will short-circuit whenever it can. - =head3 Custom matching via overloading You can change the way that an object is matched by overloading -- Perl5 Master Repository
