Quotes fixed, see also perl #36079

[p5sagit/p5-mst-13.2.git] / lib / bignum.pm

diff --git a/lib/bignum.pm b/lib/bignum.pm
index fb7db9f..951bf95 100644 (file)
--- a/lib/bignum.pm
+++ b/lib/bignum.pm
@@ -1,7 +1,7 @@
 package bignum;
 require 5.005;
 
-$VERSION = '0.13';
+$VERSION = '0.17';
 use Exporter;
 @EXPORT_OK     = qw( ); 
 @EXPORT        = qw( inf NaN ); 
@@ -33,7 +33,7 @@ sub AUTOLOAD
         if (defined $_[0])
           {
           Math::BigInt->$name($_[0]);
-          Math::BigFloat->$name($_[0]);
+          return Math::BigFloat->$name($_[0]);
           }
         return Math::BigInt->$name();
         };
@@ -63,7 +63,7 @@ sub import
   my $self = shift;
 
   # some defaults
-  my $lib = 'Calc';
+  my $lib = '';
   my $upgrade = 'Math::BigFloat';
   my $downgrade = 'Math::BigInt';
 
@@ -140,9 +140,10 @@ sub import
       }
     require Math::BigInt if $_lite == 0;       # not already loaded?
     $class = 'Math::BigInt';                   # regardless of MBIL or not
-    } 
+    }
+  push @import, 'lib' => $lib if $lib ne ''; 
   # Math::BigInt::Trace or plain Math::BigInt
-  $class->import(@import, upgrade => $upgrade, lib => $lib);
+  $class->import(@import, upgrade => $upgrade);
 
   if ($trace)
     {
@@ -291,7 +292,7 @@ overloading of '..' is not yet possible in Perl (as of v5.8.0):
 
         perl -Mbignum -le 'for (1..2) { print ref($_); }'
 
-=head2 OPTIONS
+=head2 Options
 
 bignum recognizes some options that can be passed while loading it via use.
 The options can (currently) be either a single letter form, or the long form.
@@ -333,9 +334,9 @@ line. This will be hopefully fixed soon ;)
 
 This prints out the name and version of all modules used and then exits.
 
-       perl -Mbignum=v -e ''
+       perl -Mbignum=v
 
-=head2 METHODS
+=head2 Methods
 
 Beside import() and AUTOLOAD() there are only a few other methods.
 
@@ -344,6 +345,44 @@ the BigInt or BigFloat API. It is wise to use only the bxxx() notation, and not
 the fxxx() notation, though. This makes it possible that the underlying object
 might morph into a different class than BigFloat.
 
+=head2 Caveat
+
+But a warning is in order. When using the following to make a copy of a number,
+only a shallow copy will be made.
+
+        $x = 9; $y = $x;
+        $x = $y = 7;
+
+If you want to make a real copy, use the following:
+
+        $y = $x->copy();
+
+Using the copy or the original with overloaded math is okay, e.g. the
+following work:
+
+        $x = 9; $y = $x;
+        print $x + 1, " ", $y,"\n";     # prints 10 9
+
+but calling any method that modifies the number directly will result in
+B<both> the original and the copy beeing destroyed:
+
+        $x = 9; $y = $x;
+        print $x->badd(1), " ", $y,"\n";        # prints 10 10
+
+        $x = 9; $y = $x;
+        print $x->binc(1), " ", $y,"\n";        # prints 10 10
+
+        $x = 9; $y = $x;
+        print $x->bmul(2), " ", $y,"\n";        # prints 18 18
+
+Using methods that do not modify, but testthe contents works:
+
+        $x = 9; $y = $x;
+        $z = 9 if $x->is_zero();                # works fine
+
+See the documentation about the copy constructor and C<=> in overload, as
+well as the documentation in BigInt for further details.
+
 =over 2
 
 =item inf()
@@ -442,6 +481,6 @@ as L<Math::BigInt::BitVect>, L<Math::BigInt::Pari> and  L<Math::BigInt::GMP>.
 
 =head1 AUTHORS
 
-(C) by Tels L<http://bloodgate.com/> in early 2002.
+(C) by Tels L<http://bloodgate.com/> in early 2002, 2003.
 
 =cut