diff options
Diffstat (limited to 'pod')
| -rw-r--r-- | pod/perl5112delta.pod | 22 | ||||
| -rw-r--r-- | pod/perldiag.pod | 5 | ||||
| -rw-r--r-- | pod/perlfunc.pod | 8 | ||||
| -rw-r--r-- | pod/perlsyn.pod | 8 |
4 files changed, 43 insertions, 0 deletions
diff --git a/pod/perl5112delta.pod b/pod/perl5112delta.pod index 4d524670b3..ca8c8096ff 100644 --- a/pod/perl5112delta.pod +++ b/pod/perl5112delta.pod @@ -52,6 +52,28 @@ boolean, string or number of objects. It is invoked when an object appears on the right hand side of the C<=~> operator, or when it is interpolated into a regexp. See L<overload>. +=head2 Pluggable keywords + +Extension modules can now cleanly hook into the Perl parser to define new +kinds of keyword-headed expression and compound statement. The syntax +following the keyword is defined entirely by the extension. This allow +a completely non-Perl sublanguage to be parsed inline, with the right +ops cleanly generated. + +This feature is currently considered experimental, and using it to do +anything interesting is difficult. Many necessary supporting facilities, +such as the lexer and the pad system, can only be accessed through +unsupported internal interfaces. It is intended that the Perl 5.13 +development cycle will see the addition of clean, supported interfaces +for many of these functions. In Perl 5.12 most uses of pluggable keywords +will be via L<Devel::Declare>. + +See L<perlapi/PL_keyword_plugin> for the mechanism. The Perl core source +distribution also includes a new module L<XS::APItest::KeywordRPN>, which +implements reverse Polish notation arithmetic via pluggable keywords. +This module is mainly used for test purposes, and is not normally +installed, but also serves as an example of how to use the new mechanism. + =head1 New Platforms XXX List any platforms that this version of perl compiles on, that previous diff --git a/pod/perldiag.pod b/pod/perldiag.pod index 3f0a78a3fe..db9a17c2fb 100644 --- a/pod/perldiag.pod +++ b/pod/perldiag.pod @@ -373,6 +373,11 @@ is not the same as $var = 'myvar'; $sym = "mypack::$var"; +=item Bad plugin affecting keyword '%s' + +(F) An extension using the keyword plugin mechanism violated the +plugin API. + =item Bad realloc() ignored (S malloc) An internal routine called realloc() on something that had diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod index c440faa410..862e0ba73d 100644 --- a/pod/perlfunc.pod +++ b/pod/perlfunc.pod @@ -86,6 +86,14 @@ which return C<-1> on failure. Exceptions to this rule are C<wait>, C<waitpid>, and C<syscall>. System calls also set the special C<$!> variable on failure. Other functions do not, except accidentally. +Extension modules can also hook into the Perl parser to define new +kinds of keyword-headed expression. These may look like functions, but +may also look completely different. The syntax following the keyword +is defined entirely by the extension. If you are an implementor, see +L<perlapi/PL_keyword_plugin> for the mechanism. If you are using such +a module, see the module's documentation for details of the syntax that +it defines. + =head2 Perl Functions by Category X<function> diff --git a/pod/perlsyn.pod b/pod/perlsyn.pod index 5e80901b09..d5fc4a72c1 100644 --- a/pod/perlsyn.pod +++ b/pod/perlsyn.pod @@ -272,6 +272,14 @@ conditional is about to be evaluated again. Thus it can be used to increment a loop variable, even when the loop has been continued via the C<next> statement. +Extension modules can also hook into the Perl parser to define new +kinds of compound statement. These are introduced by a keyword which +the extension recognises, and the syntax following the keyword is +defined entirely by the extension. If you are an implementor, see +L<perlapi/PL_keyword_plugin> for the mechanism. If you are using such +a module, see the module's documentation for details of the syntax that +it defines. + =head2 Loop Control X<loop control> X<loop, control> X<next> X<last> X<redo> X<continue> |