X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fbigrat.pm;h=30acd275607ba930f17d5d0ab0caa2f259f09d7b;hb=2da7a6b5eab232c468b68576568f84877f032fd6;hp=884e9dab315a4c528c4953873c62f2c333571d5a;hpb=d1a15766ff5cdfaf84d91442a68bc2a05880bf12;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/bigrat.pm b/lib/bigrat.pm
index 884e9da..30acd27 100644
--- a/lib/bigrat.pm
+++ b/lib/bigrat.pm
@@ -4,8 +4,8 @@ use 5.006002;
 $VERSION = '0.22';
 require Exporter;
 @ISA		= qw( bigint );
-@EXPORT_OK	= qw( ); 
-@EXPORT		= qw( inf NaN ); 
+@EXPORT_OK 	= qw( PI e bpi bexp );
+@EXPORT		= qw( inf NaN );
 
 use strict;
 use overload;
@@ -95,12 +95,12 @@ sub import
 
   $^H{bigrat} = 1;					# we are in effect
 
+  my ($hex,$oct);
   # for newer Perls always override hex() and oct() with a lexical version:
   if ($] > 5.009004)
     {
-    no warnings 'redefine';
-    *CORE::GLOBAL::oct = \&_oct;
-    *CORE::GLOBAL::hex = \&_hex;
+    $oct = \&_oct;
+    $hex = \&_hex;
     }
   # some defaults
   my $lib = ''; my $lib_kind = 'try'; my $upgrade = 'Math::BigFloat';
@@ -151,16 +151,14 @@ sub import
     elsif ($_[$i] eq 'hex')
       {
       splice @a, $j, 1; $j --;
-      no warnings 'redefine';
-      *CORE::GLOBAL::hex = \&bigint::_hex_global;
+      $hex = \&bigint::_hex_global;
       }
     elsif ($_[$i] eq 'oct')
       {
       splice @a, $j, 1; $j --;
-      no warnings 'redefine';
-      *CORE::GLOBAL::oct = \&bigint::_oct_global;
+      $oct = \&bigint::_oct_global;
       }
-    else
+    elsif ($_[$i] !~ /^(PI|e|bpi|bexp)\z/)
       {
       die ("unknown option $_[$i]");
       }
@@ -221,6 +219,22 @@ sub import
     {
     $self->export_to_level(1,$self,@a);           # export inf and NaN
     }
+  {
+    no warnings 'redefine';
+    *CORE::GLOBAL::oct = $oct if $oct;
+    *CORE::GLOBAL::hex = $hex if $hex;
+  }
+  }
+
+sub PI () { Math::BigFloat->new('3.141592653589793238462643383279502884197'); }
+sub e () { Math::BigFloat->new('2.718281828459045235360287471352662497757'); }
+
+sub bpi ($) { local $Math::BigFloat::upgrade; Math::BigFloat::bpi(@_); }
+
+sub bexp ($$)
+  {
+  local $Math::BigFloat::upgrade;
+  my $x = Math::BigFloat->new($_[0]); $x->bexp($_[1]);
   }
 
 1;
@@ -326,6 +340,40 @@ handle bareword C<inf> properly.
 A shortcut to return Math::BigInt->bnan(). Useful because Perl does not always
 handle bareword C<NaN> properly.
 
+=item e
+
+	# perl -Mbigrat=e -wle 'print e'
+
+Returns Euler's number C<e>, aka exp(1).
+
+=item PI
+
+	# perl -Mbigrat=PI -wle 'print PI'
+
+Returns PI.
+
+=item bexp()
+
+	bexp($power,$accuracy);
+
+
+Returns Euler's number C<e> raised to the appropriate power, to
+the wanted accuracy.
+
+Example:
+
+	# perl -Mbigrat=bexp -wle 'print bexp(1,80)'
+
+=item bpi()
+
+	bpi($accuracy);
+
+Returns PI to the wanted accuracy.
+
+Example:
+
+	# perl -Mbigrat=bpi -wle 'print bpi(80)'
+
 =item upgrade()
 
 Return the class that numbers are upgraded to, is in fact returning
@@ -437,13 +485,13 @@ This will be hopefully fixed soon ;)
 
 =item hex
 
-Override the build-in hex() method with a version that can handle big
+Override the built-in hex() method with a version that can handle big
 integers. Note that under Perl v5.9.4 or ealier, this will be global
 and cannot be disabled with "no bigint;".
 
 =item oct
 
-Override the build-in oct() method with a version that can handle big
+Override the built-in oct() method with a version that can handle big
 integers. Note that under Perl v5.9.4 or ealier, this will be global
 and cannot be disabled with "no bigint;".