Change 31368 by [EMAIL PROTECTED] on 2007/06/12 08:39:00
Subject: Re: integer vs. bigint [PATCH]
From: Tels <[EMAIL PROTECTED]>
Date: Mon, 11 Jun 2007 19:31:16 +0200
Message-Id: <[EMAIL PROTECTED]>
Affected files ...
... //depot/perl/lib/bigint.pm#15 edit
Differences ...
==== //depot/perl/lib/bigint.pm#15 (text) ====
Index: perl/lib/bigint.pm
--- perl/lib/bigint.pm#14~31269~ 2007-05-24 10:18:24.000000000 -0700
+++ perl/lib/bigint.pm 2007-06-12 01:39:00.000000000 -0700
@@ -247,8 +247,44 @@
All operators (including basic math operations) are overloaded. Integer
constants are created as proper BigInts.
-Floating point constants are truncated to integer. All results are also
-truncated.
+Floating point constants are truncated to integer. All parts and results of
+expressions are also truncated.
+
+Unlike L<integer>, this pragma creates integer constants that are only
+limited in their size by the available memory and CPU time.
+
+=head2 use integer vs. use bigint
+
+There is one small difference between C<use integer> and C<use bigint>: the
+former will not affect assignments to variables and the return value of
+some functions. C<bigint> truncates these results to integer too:
+
+ # perl -Minteger -wle 'print 3.2'
+ 3.2
+ # perl -Minteger -wle 'print 3.2 + 0'
+ 3
+ # perl -Mbigint -wle 'print 3.2'
+ 3
+ # perl -Mbigint -wle 'print 3.2 + 0'
+ 3
+
+ # perl -Mbigint -wle 'print exp(1) + 0'
+ 2
+ # perl -Mbigint -wle 'print exp(1)'
+ 2
+ # perl -Mbigint -wle 'print exp(1)'
+ 2.71828182845905
+ # perl -Mbigint -wle 'print exp(1) + 0'
+ 2
+
+In practice this makes seldom a difference as B<parts and results> of
+expressions will be truncated anyway, but this can, for instance, affect the
+return value of subroutines:
+
+ sub three_integer { use integer; return 3.2; }
+ sub three_bigint { use bigint; return 3.2; }
+
+ print three_integer(), " ", three_bigint(),"\n"; # prints "3.2 3"
=head2 Options
End of Patch.
