X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2FLexical-Types.git;a=blobdiff_plain;f=README;h=919e0afe5d8cda6269335e27e72deae4b9c87fbf;hp=bba2ba0abf2a26a97a95b0b3d9f78a1f47250147;hb=2ca2925dc02c506e0c026e262bbcb4e7a1e18b27;hpb=ef454c52e92ecd149b3bf0f6e221162cad3955ac

diff --git a/README b/README
index bba2ba0..919e0af 100644
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
     Lexical::Types - Extend the semantics of typed lexicals.
 
 VERSION
-    Version 0.03
+    Version 0.12
 
 SYNOPSIS
         { package Str; }
@@ -31,10 +31,20 @@ SYNOPSIS
 
 DESCRIPTION
     This pragma allows you to hook the execution of typed lexicals
-    declarations ("my Str $x"). In particular, it can be used to
-    automatically tie or bless typed lexicals.
+    declarations ("my Str $x") by calling a configurable method in a
+    configurable package at each run. In particular, it can be used to
+    automatically tie or bless typed lexicals whenever they are initialized.
 
-    It is not implemented with a source filter.
+    Remind that for "perl" to be able to parse "my Str $x", you need :
+
+    *   either the "Str" package to be defined ;
+
+    *   or for "Str" to be a constant sub returning a valid defined package.
+
+    so make sure you follow one of those two strategies to define your
+    types.
+
+    This pragma is not implemented with a source filter.
 
 FUNCTIONS
   "import [ as => [ $prefix | $mangler ] ]"
@@ -73,14 +83,38 @@ FUNCTIONS
                 use Lexical::Types as => sub { 'My', 'new_' . lc($_[0]) };
                 my Str $x; # the coderef indicates to call My->new_str
 
-    The initializer method receives an alias to the pad entry of $x in $_[1]
-    and the original type name ("Str") in $_[2]. You can either edit $_[1]
-    in place, in which case you should return an empty list, or return a new
-    scalar that will be copied into $x.
+        Note that if the type is a constant, $_[0] will be set to the
+        *value* of constant and not to its name.
+
+            use Lexical::Types as => sub { $_[0] => 'new' };
+            use constant Str => 'MyStr';
+            my Str $x; # calls MyStr->new
+
+        This means in particular that you can't both use constant types and
+        redirect several types to different methods of the same package,
+        because then you can't distinguish between the original types with
+        $_[0].
 
   "unimport"
     Magically called when writing "no Lexical::Types". Turns the pragma off.
 
+RUN-TIME INITIALIZER METHOD
+    The initializer method receives an alias to the pad slot of the
+    initialized lexical in $_[1] and the original type name in $_[2]. You
+    can either edit $_[1] in place, in which case you should return an empty
+    list, or return a new scalar that will be copied into the pad slot.
+
+        use Lexical::Types as => 'My';
+
+        my Str $x;
+
+        ...
+
+        sub My::Str::TYPEDSCALAR {
+         # $_[1] is an alias to $x, and $_[2] is 'Str'
+         ...
+        }
+
 INTEGRATION
     You can integrate Lexical::Types in your module so that using it will
     provide types to your users without asking them to load either
@@ -105,22 +139,73 @@ INTEGRATION
 
         sub new_int { ... }
 
-CAVEATS
-    For "perl" to be able to parse "my Str $x", you need :
+    If you prefer to use constants rather than creating empty packages, you
+    can replace the previous example with something like this :
 
-    *   either the "Str" package to be defined ;
+        package MyTypes;
 
-    *   or for "Str" to be a constant sub returning a valid defined package.
+        BEGIN { require Lexical::Types; }
 
-    Those restrictions apply even if you use the 'as' option to redirect to
-    another package, and are unlikely to find a workaround as this happens
-    deep inside the lexer - far from the reach of an extension.
+        sub import {
+         my $pkg = caller;
+         for (qw<Str Int>) {
+          my $type = __PACKAGE__ . '::' . $_;
+          no strict 'refs';
+          no warnings 'redefine';
+          *{$pkg.'::'.$_} = eval "sub () { '$type' }";
+         }
+         Lexical::Types->import(
+          as => sub { $_[0] => 'new' }
+         );
+        }
+
+        sub unimport {
+         Lexical::Types->unimport;
+        }
+
+        package MyTypes::Str;
+
+        sub new { ... }
+
+        package MyTypes::Int;
+
+        sub new { ... }
+
+CONSTANTS
+  "LT_THREADSAFE"
+    True iff the module could have been built with thread-safety features
+    enabled.
+
+  "LT_FORKSAFE"
+    True iff this module could have been built with fork-safety features
+    enabled. This will always be true except on Windows where it's false for
+    perl 5.10.0 and below .
+
+CAVEATS
+    The restrictions on the type (being either a defined package name or a
+    constant) apply even if you use the 'as' option to redirect to another
+    package, and are unlikely to find a workaround as this happens deep
+    inside the lexer - far from the reach of an extension.
 
     Only one mangler or prefix can be in use at the same time in a given
     scope.
 
+    The implementation was tweaked to work around several limitations of
+    vanilla "perl" pragmas : it's thread safe, and doesn't suffer from a
+    "perl 5.8.x-5.10.0" bug that causes all pragmas to propagate into
+    "require"d scopes.
+
+    With 5.8 perls, the pragma does not propagate into "eval STRING". This
+    is due to a shortcoming in the way perl handles the hints hash, which is
+    addressed in perl 5.10.
+
 DEPENDENCIES
-    perl 5.8, XSLoader.
+    perl 5.8.3.
+
+    A C compiler. This module may happen to build with a C++ compiler as
+    well, but don't rely on it, as no guarantee is made in this regard.
+
+    XSLoader (standard since perl 5.006).
 
 SEE ALSO
     fields.
@@ -153,7 +238,7 @@ ACKNOWLEDGEMENTS
     Thanks Florian Ragwitz for suggesting the use of constants for types.
 
 COPYRIGHT & LICENSE
-    Copyright 2009 Vincent Pit, all rights reserved.
+    Copyright 2009,2010,2011 Vincent Pit, all rights reserved.
 
     This program is free software; you can redistribute it and/or modify it
     under the same terms as Perl itself.