Typo in POD

[perl/modules/Variable-Magic.git] / README

diff --git a/README b/README
index cc595c27747557e242836547d9149cf9dcd8842b..e04ba968017b28339c5c7dcc91c7a1bddf98aee5 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION
-    Version 0.50
+    Version 0.52
 
 SYNOPSIS
         use Variable::Magic qw<wizard cast VMG_OP_INFO_NAME>;
@@ -63,13 +63,18 @@ DESCRIPTION
         the correct "Tie::Std*" class and overriding individual methods in
         your own class.
 
+    *   Magic is multivalued.
+
+        You can safely apply different kinds of magics to the same variable,
+        and each of them will be invoked successively.
+
     *   Magic is type-agnostic.
 
         The same magic can be applied on scalars, arrays, hashes, subs or
         globs. But the same hook (see below for a list) may trigger
         differently depending on the the type of the variable.
 
-    *   Magic is invisible at the Perl level.
+    *   Magic is invisible at Perl level.
 
         Magical and non-magical variables cannot be distinguished with
         "ref", "tied" or another trick.
@@ -95,11 +100,19 @@ DESCRIPTION
 
     *   *len*
 
-        This magic only applies to scalars and arrays, and is triggered when
-        the 'size' or the 'length' of the variable has to be known by Perl.
-        This is typically the magic involved when an array is evaluated in
-        scalar context, but also on array assignment and loops ("for", "map"
-        or "grep"). The length is returned from the callback as an integer.
+        This magic only applies to arrays (though it used to also apply to
+        scalars), and is triggered when the 'size' or the 'length' of the
+        variable has to be known by Perl. This is typically the magic
+        involved when an array is evaluated in scalar context, but also on
+        array assignment and loops ("for", "map" or "grep"). The length is
+        returned from the callback as an integer.
+
+        Starting from perl 5.12, this magic is no longer called by the
+        "length" keyword, and starting from perl 5.17.4 it is also no longer
+        called for scalars in any situation, making this magic only
+        meaningful on arrays. You can use the constants
+        "VMG_COMPAT_SCALAR_LENGTH_NOLEN" and "VMG_COMPAT_SCALAR_NOLEN" to
+        see if this magic is available for scalars or not.
 
     *   *clear*
 
@@ -111,9 +124,11 @@ DESCRIPTION
 
     *   *free*
 
-        This magic is called when an object is destroyed as the result of
-        the variable going out of scope (but not when the variable is
-        undefined).
+        This magic is called when a variable is destroyed as the result of
+        going out of scope (but not when it is undefined). It behaves
+        roughly like Perl object destructors (i.e. "DESTROY" methods),
+        except that exceptions thrown from inside a *free* callback will
+        always be propagated to the surrounding code.
 
     *   *copy*
 
@@ -346,6 +361,10 @@ CONSTANTS
     True for perls that don't call *len* magic when taking the "length" of a
     magical scalar.
 
+  "VMG_COMPAT_SCALAR_NOLEN"
+    True for perls that don't call *len* magic on scalars. Implies
+    "VMG_COMPAT_SCALAR_LENGTH_NOLEN".
+
   "VMG_COMPAT_ARRAY_PUSH_NOLEN"
     True for perls that don't call *len* magic when you push an element in a
     magical array. Starting from perl 5.11.0, this only refers to pushes in