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[perl/modules/indirect.git] / README

diff --git a/README b/README
index c8d4438069cd48b8c935dbfb0066d55407211097..a254d34e5faf457aba026e38de3c7627ef58446a 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
     indirect - Lexically warn about using the indirect object syntax.
 
 VERSION
-    Version 0.12
+    Version 0.19
 
 SYNOPSIS
         # In a script
@@ -12,10 +12,12 @@ SYNOPSIS
          use indirect;
          my $y = new Pear; # ok
          {
-          no indirect hook => sub { die "You really wanted $_[0]\->$_[1]" };
-          my $z = new Pineapple 'fresh'; # croaks 'You really wanted Pineapple->new'
+          no indirect hook => sub { die "You really wanted $_[0]\->$_[1] at $_[2]:$_[3]" };
+          my $z = new Pineapple 'fresh'; # croaks 'You really wanted Pineapple->new at blurp.pm:13'
          }
         }
+        try { ... }; # warns
+
         no indirect ':fatal';
         if (defied $foo) { ... } # croaks, note the typo
 
@@ -31,13 +33,12 @@ DESCRIPTION
     turn it on by calling "no indirect"), this pragma warns about indirect
     object syntax constructs that may have slipped into your code. This
     syntax is now considered harmful, since its parsing has many quirks and
-    its use is error prone (when "sub" isn't defined, "sub $x" is actually
-    interpreted as "$x->sub").
+    its use is error prone (when "swoosh" isn't defined, "swoosh $x"
+    actually compiles to "$x->swoosh").
 
-    It currently does not warn when the object is enclosed between braces
-    (like "meth { $obj } @args") or for core functions ("print" or "say").
-    This may change in the future, or may be added as optional features that
-    would be enabled by passing options to "unimport".
+    It currently does not warn for core functions ("print", "say", "exec" or
+    "system"). This may change in the future, or may be added as optional
+    features that would be enabled by passing options to "unimport".
 
     This module is not a source filter.
 
@@ -50,19 +51,59 @@ METHODS
         indirect syntax met.
 
     *   If the key/value pair "hook => $hook" comes first, $hook will be
-        called for each error with the object name as $_[0] and the method
-        name as $_[1].
+        called for each error with a string representation of the object as
+        $_[0], the method name as $_[1], the current file as $_[2] and the
+        line number as $_[3]. If and only if the object is actually a block,
+        $_[0] is assured to start by '{'.
 
     *   Otherwise, a warning will be emitted for each indirect construct.
 
   "import"
     Magically called at each "use indirect". Turns the module off.
 
+FUNCTIONS
+  "msg $object, $method, $file, $line"
+    Returns the default error message generated by "indirect" when an
+    invalid construct is reported.
+
 CONSTANTS
   "I_THREADSAFE"
-    True iff the module could have been built when thread-safety features.
+    True iff the module could have been built with thread-safety features
+    enabled.
+
+  "I_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 .
+
+DIAGNOSTICS
+  "Indirect call of method "%s" on object "%s" at %s line %d."
+    The default warning/exception message thrown when an indirect call on an
+    object is found.
+
+  "Indirect call of method "%s" on a block at %s line %d."
+    The default warning/exception message thrown when an indirect call on a
+    block is found.
+
+ENVIRONMENT
+  "PERL_INDIRECT_PM_DISABLE"
+    If this environment variable is set to true when the pragma is used for
+    the first time, the XS code won't be loaded and, although the 'indirect'
+    lexical hint will be set to true in the scope of use, the pragma itself
+    won't do anything. In this case, the pragma will always be considered to
+    be thread-safe, and as such "I_THREADSAFE" will be true. This is useful
+    for disabling "indirect" in production environments.
+
+    Note that clearing this variable after "indirect" was loaded has no
+    effect. If you want to reenable the pragma later, you also need to
+    reload it by deleting the 'indirect.pm' entry from %INC.
 
 CAVEATS
+    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.
+
     "meth $obj" (no semicolon) at the end of a file won't be seen as an
     indirect object syntax, although it will as soon as there is another
     token before the end (as in "meth $obj;" or "meth $obj 1").
@@ -71,6 +112,9 @@ CAVEATS
     is due to a shortcoming in the way perl handles the hints hash, which is
     addressed in perl 5.10.
 
+    The search for indirect method calls happens before constant folding.
+    Hence "my $x = new Class if 0" will be caught.
+
 DEPENDENCIES
     perl 5.8.
 
@@ -99,6 +143,9 @@ SUPPORT
 ACKNOWLEDGEMENTS
     Bram, for motivation and advices.
 
+    Andrew Main and Florian Ragwitz, for testing on real-life code and
+    reporting issues.
+
 COPYRIGHT & LICENSE
     Copyright 2008-2009 Vincent Pit, all rights reserved.