A quick new release of Pod-Simple has removed the dependency on

[perl5.git] / lib / Memoize.pm

diff --git a/lib/Memoize.pm b/lib/Memoize.pm
index 6907400..a7f29de 100644 (file)
--- a/lib/Memoize.pm
+++ b/lib/Memoize.pm
@@ -8,10 +8,10 @@
 # same terms as Perl itself.  If in doubt, 
 # write to mjd-perl-memoize+@plover.com for a license.
 #
-# Version 0.66 $Revision: 1.18 $ $Date: 2001/06/24 17:16:47 $
+# Version 1.01 $Revision: 1.18 $ $Date: 2001/06/24 17:16:47 $
 
 package Memoize;
-$VERSION = '0.66';
+$VERSION = '1.01_02';
 
 # Compile-time constants
 sub SCALAR () { 0 } 
@@ -176,8 +176,8 @@ sub _my_tie {
   my $shortopt = (ref $fullopt) ? $fullopt->[0] : $fullopt;
   
   return unless defined $shortopt && $shortopt eq 'TIE';
-  carp("TIE option to memoize() is deprecated; use HASH instead") if $^W;
-
+  carp("TIE option to memoize() is deprecated; use HASH instead")
+      if $^W;
 
   my @args = ref $fullopt ? @$fullopt : ();
   shift @args;
@@ -266,8 +266,9 @@ sub _memoizer {
       # Otherwise, we cached an array containing the returned list:
       return @$val;
     } else {
-      my $q = $cache->{$argstr} = [&{$info->{U}}(@_)];
-      @$q;
+        my @q = &{$info->{U}}(@_);
+        $cache->{$argstr} = $info->{O}{LIST_CACHE} eq 'MERGE' ? $q [0] : \@q;
+        @q;
     }
   } else {
     croak "Internal error \#42; context was neither LIST nor SCALAR\n";
@@ -357,10 +358,11 @@ sub _crap_out {
 
 =head1 NAME
 
-Memoize - Make your functions faster by trading space for time
+Memoize - Make functions faster by trading space for time
 
 =head1 SYNOPSIS
 
+        # This is the documentation for Memoize 1.01
        use Memoize;
        memoize('slow_function');
        slow_function(arguments);    # Is faster than it was before
@@ -462,7 +464,7 @@ this:
 
 Since there are relatively few objects in a picture, there are only a
 few colors, which get looked up over and over again.  Memoizing
-C<ColorToRGB> speeded up the program by several percent.
+C<ColorToRGB> sped up the program by several percent.
 
 =head1 DETAILS
 
@@ -692,15 +694,18 @@ because all its results have been precomputed.
 
 =item C<TIE>
 
-This option is B<strongly deprecated> and will be removed
-in the B<next> release of C<Memoize>.  Use the C<HASH> option instead.
+This option is no longer supported.  It is still documented only to
+aid in the debugging of old programs that use it.  Old programs should
+be converted to use the C<HASH> option instead.
 
         memoize ... [TIE, PACKAGE, ARGS...]
 
 is merely a shortcut for
 
         require PACKAGE;
-        tie my %cache, PACKAGE, ARGS...;
+       { my %cache;
+          tie %cache, PACKAGE, ARGS...;
+       }
         memoize ... [HASH => \%cache];
 
 =item C<FAULT>
@@ -975,15 +980,12 @@ in Perl, and until it is resolved, memoized functions will see a
 slightly different C<caller()> and will perform a little more slowly
 on threaded perls than unthreaded perls.
 
-Here's a bug that isn't my fault: Some versions of C<DB_File> won't
-let you store data under a key of length 0.  That means that if you
-have a function C<f> which you memoized and the cache is in a
-C<DB_File> database, then the value of C<f()> (C<f> called with no
-arguments) will not be memoized.  Let us all breathe deeply and repeat
-this mantra: ``Gosh, Keith, that sure was a stupid thing to do.''  If
-this is a big problem, you can write a tied hash class which is a
-front-end to C<DB_File> that prepends <x> to every key before storing
-it.
+Some versions of C<DB_File> won't let you store data under a key of
+length 0.  That means that if you have a function C<f> which you
+memoized and the cache is in a C<DB_File> database, then the value of
+C<f()> (C<f> called with no arguments) will not be memoized.  If this
+is a big problem, you can supply a normalizer function that prepends
+C<"x"> to every key.
 
 =head1 MAILING LIST
 
@@ -1001,11 +1003,10 @@ memoization and about the internals of Memoize that appeared in The
 Perl Journal, issue #13.  (This article is also included in the
 Memoize distribution as `article.html'.)
 
-My upcoming book will discuss memoization (and many other fascinating
-topics) in tremendous detail.  It will be published by Morgan Kaufmann
-in 2002, possibly under the title I<Perl Advanced Techniques
-Handbook>.  It will also be available on-line for free.  For more
-information, visit http://perl.plover.com/book/ .
+The author's book I<Higher Order Perl> (2005, ISBN 1558607013, published
+by Morgan Kaufmann) discusses memoization (and many other fascinating
+topics) in tremendous detail. It will also be available on-line for free.
+For more information, visit http://perl.plover.com/book/ .
 
 To join a mailing list for announcements about C<Memoize>, send an
 empty message to C<mjd-perl-memoize-request@plover.com>.  This mailing