[S32::Exception] better error message for X::Numeric::Real

also fix a typo

Author: moritz

S32-setting-library/Exception.pod

@@ -17,8 +17,8 @@ Authors of previous versions of this document:
 
     Created: 26 Feb 2009
 
-    Last Modified: 22 August 2012
-    Version: 22
+    Last Modified: 23 August 2012
+    Version: 23
 
 The document is a draft.
 
@@ -968,7 +968,7 @@ Thrown when hash assignment finds a trailing hash key with a value.
         method message() { "Odd number of elements found where hash expected" }
     }
 
-=head2 X::Phaser::PrePos
+=head2 X::Phaser::PrePost
 
 Thrown when the condition inside a C<PRE> or C<POST> phaser evaluate to a
 false value.
@@ -1251,11 +1251,12 @@ Occurs when an attempt to coerce a C<Numeric> to a C<Real>, C<Num>, C<Int> or
 C<Rat> fails (due to a number with a nonzero imaginary part, for instance).
 
     my class X::Numeric::Real is Exception {
+        has $.source;
         has $.target;
         has $.reason;
 
         method message() {
-            "Can not convert Numeric to {$.target.^name}: $.reason";
+            "Can not convert $.source to {$.target.^name}: $.reason";
         }
     }