c07766a234204d78a80b6d75534e03ae3465b6f3 is a better fix for RT #47902 than 4cb0e2cc2...

[perl/modules/indirect.git] / README

diff --git a/README b/README
index 18baca1937f77f7e2ae3bc8d39b1aada845f2bd4..d1b1229c0221abc04437cd1c09e0c1686ce43317 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
     indirect - Lexically warn about using the indirect object syntax.
 
 VERSION
-    Version 0.13
+    Version 0.18
 
 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 +51,53 @@ 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], the method name
-        as $_[1], the current file as $_[2] and the line number as $_[3].
+        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.
+
+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. 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 +106,9 @@ 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 +137,9 @@ 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.