diff options
Diffstat (limited to 'contrib/perl5/pod/perlsub.pod')
| -rw-r--r-- | contrib/perl5/pod/perlsub.pod | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/contrib/perl5/pod/perlsub.pod b/contrib/perl5/pod/perlsub.pod index 957b3d8..bfab0fe 100644 --- a/contrib/perl5/pod/perlsub.pod +++ b/contrib/perl5/pod/perlsub.pod @@ -199,7 +199,7 @@ pre-defined things are C<BEGIN>, C<END>, C<AUTOLOAD>, and C<DESTROY>--plus all t functions mentioned in L<perltie>. The 5.005 release adds C<INIT> to this list. -=head2 Private Variables via C<my()> +=head2 Private Variables via my() Synopsis: @@ -381,7 +381,7 @@ unqualified and unqualifiable. This does not work with object methods, however; all object methods have to be in the symbol table of some package to be found. -=head2 Peristent Private Variables +=head2 Persistent Private Variables Just because a lexical variable is lexically (also called statically) scoped to its enclosing block, C<eval>, or C<do> FILE, this doesn't mean that @@ -581,6 +581,28 @@ Perl will print This is a test only a test. The array has 6 elements: 0, 1, 2, undef, undef, 5 +Note also that when you C<local>ize a member of a composite type that +B<does not exist previously>, the value is treated as though it were +in an lvalue context, i.e., it is first created and then C<local>ized. +The consequence of this is that the hash or array is in fact permanently +modified. For instance, if you say + + %hash = ( 'This' => 'is', 'a' => 'test' ); + @ary = ( 0..5 ); + { + local($ary[8]) = 0; + local($hash{'b'}) = 'whatever'; + } + printf "%%hash has now %d keys, \@ary %d elements.\n", + scalar(keys(%hash)), scalar(@ary); + +Perl will print + + %hash has now 3 keys, @ary 9 elements. + +The above behavior of local() on non-existent members of composite +types is subject to change in future. + =head2 Passing Symbol Table Entries (typeglobs) [Note: The mechanism described in this section was originally the only @@ -825,7 +847,8 @@ if you call it like a builtin function, then it behaves like a builtin function. If you call it like an old-fashioned subroutine, then it behaves like an old-fashioned subroutine. It naturally falls out from this rule that prototypes have no influence on subroutine references -like C<\&foo> or on indirect subroutine calls like C<&{$subref}>. +like C<\&foo> or on indirect subroutine calls like C<&{$subref}> or +C<$subref-E<gt>()>. Method calls are not influenced by prototypes either, because the function to be called is indeterminate at compile time, because it depends @@ -863,8 +886,10 @@ unbackslashed C<@> or C<%> eats all the rest of the arguments, and forces list context. An argument represented by C<$> forces scalar context. An C<&> requires an anonymous subroutine, which, if passed as the first argument, does not require the "C<sub>" keyword or a subsequent comma. A -C<*> does whatever it has to do to turn the argument into a reference to a -symbol table entry. +C<*> allows the subroutine to accept a bareword, constant, scalar expression, +typeglob, or a reference to a typeglob in that slot. The value will be +available to the subroutine either as a simple scalar, or (in the latter +two cases) as a reference to the typeglob. A semicolon separates mandatory arguments from optional arguments. (It is redundant before C<@> or C<%>.) |
