Added new POD, tests and ability to pass arrayref to import which has…

… names of PDL::Util functions to be made methods

README.pod

@@ -16,3 +16,34 @@ PDL::Util
 
 Convenient utility functions/methods for use with PDL.
 
+=head1 IMPORT
+
+PDL::Util does not export anything by default. The exportable symbols come in two types, functions and methods. Methods is a strange word. When importing symbols one does not import methods. In this context a 'method' is a function which expects a piddle as its first argument. 
+
+A list of symbols may be imported as usual. Tags may be imported as ':functions' and ':methods'. More interestingly if an array reference or hash reference is passed as the last item in the import list, its contents will be passed to the L<add_pdl_method> function below, in which case these functions are imported into the PDL namespace and may be used as method calls. Note, when doing this for symbols from the PDL::Util module, only those listed in the ':methods' tag may be added as a method (this is the origin of the confusing terminology). Read carefully before using this functionality.
+
+=head1 TAG :functions
+
+=head2 add_pdl_method
+
+=head1 TAG :methods
+
+Again, the FUNCTIONS provided in the method tag are not automatically methods. They simply are function which are called with a PDL object (piddle) as their first argument. This function ARE available to be imported into the PDL namespace using the L<add_pdl_method> function describe above.
+
+=head2 unroll
+
+=head2 export2d
+
+ export2d($pdl, $fh, ',');
+   -- or --
+ $pdl->export2d($fh, ',');
+
+C<export2d> may take up to 2 optional arguments, a lexical filehandle (or globref, e.g. C<\*FILE>) to write to, and a string containing a column separator. The defaults, if arguments are not given are to print to STDOUT and use a single space as the column separator. The order does not matter, the method will determine whether an argument refers to a file or not. This is done so that one may call either
+
+ $pdl->export2d($fh);
+ $pdl->export2d(',');
+
+and it will do what you mean. Unfortunately this means that unlike C<wcols> one cannot use a filename rather than a filehandle; C<export2d> would interpret the string as the column separator!
+
+The method returns the number of columns that were written.
+

lib/PDL/Util.pm

@@ -1,36 +1,75 @@
 package PDL::Util;
 
+=head1 NAME
+
+PDL::Util
+
+=head1 SYNOPSIS
+
+ use PDL;
+ use PDL::Util 'export2d';
+
+ my $pdl = rvals(6,4);
+
+ open my $fh, '>', 'file.dat';
+ export2d($pdl, $fh);
+
+=head1 DESCRIPTION
+
+Convenient utility functions/methods for use with PDL.
+
+=cut
+
 use PDL;
 use Scalar::Util qw/openhandle blessed/;
 
 use Carp;
 
 use parent 'Exporter';
-our @EXPORT_OK = qw/
-  add_pdl_method
-  export2d
-  unroll
-/;
 our %EXPORT_TAGS = (
-  all => \@EXPORT_OK,
+  functions => [qw/add_pdl_method/],
+  methods   => [qw/unroll export2d/],
 );
 
+our @EXPORT_OK;
+push @EXPORT_OK, @$_ for values %EXPORT_TAGS;
+
+$EXPORT_TAGS{'all'} = \@EXPORT_OK;
+
+=head1 IMPORT
+
+PDL::Util does not export anything by default. The exportable symbols come in two types, functions and methods. Methods is a strange word. When importing symbols one does not import methods. In this context a 'method' is a function which expects a piddle as its first argument. 
+
+A list of symbols may be imported as usual. Tags may be imported as ':functions' and ':methods'. More interestingly if an array reference or hash reference is passed as the last item in the import list, its contents will be passed to the L<add_pdl_method> function below, in which case these functions are imported into the PDL namespace and may be used as method calls. Note, when doing this for symbols from the PDL::Util module, only those listed in the ':methods' tag may be added as a method (this is the origin of the confusing terminology). Read carefully before using this functionality.
+
+=cut
+
 sub import {
   my $package = shift;
   return 1 unless @_;
 
   my $ref_last = ref $_[-1] || '';
-  my $method_spec = $ref_last eq 'HASH' ? pop : 0;
+  my $method_spec = ( grep {$ref_last eq $_} qw/HASH ARRAY/ ) ? pop : 0;
 
   add_pdl_method($method_spec) if ($method_spec);
 
   __PACKAGE__->export_to_level(1, $package, @_) if @_;
 }
 
+=head1 TAG :functions
+
+=head2 add_pdl_method
+
+=cut
+
 sub add_pdl_method {
   my $spec = shift;
-  croak 'make_pdl_method expects a hash reference as its argument' 
-    unless ref $spec eq 'HASH';
+  croak 'make_pdl_method expects a hash or array reference as its argument' 
+    unless grep {ref $spec eq $_} qw/HASH ARRAY/;
+
+  if (ref $spec eq 'ARRAY') {
+    $spec = { map { $_ => $_ } @$spec };
+  } 
 
   foreach my $method (keys %$spec) {
     my $function = $spec->{$method};
@@ -41,7 +80,7 @@ PDL already provides a method named '$method', read the PDL::Util documentation
 MESSAGE
 
     unless (ref $function && ref $function eq 'CODE') {
-      if ( 1 == grep { $_ eq $function } @EXPORT_OK ) {
+      if ( 1 == grep { $_ eq $function } @{ $EXPORT_TAGS{'methods'} } ) {
         no strict 'refs';
         $function = \&{ 'PDL::Util::' . $function };
       } else {
@@ -54,6 +93,14 @@ MESSAGE
   }
 }
 
+=head1 TAG :methods
+
+Again, the FUNCTIONS provided in the method tag are not automatically methods. They simply are function which are called with a PDL object (piddle) as their first argument. This function ARE available to be imported into the PDL namespace using the L<add_pdl_method> function describe above.
+
+=head2 unroll
+
+=cut
+
 sub unroll {
  my $pdl = shift;
 
@@ -69,6 +116,23 @@ sub unroll {
 
 }
 
+=head2 export2d
+
+ export2d($pdl, $fh, ',');
+   -- or --
+ $pdl->export2d($fh, ',');
+
+C<export2d> may take up to 2 optional arguments, a lexical filehandle (or globref, e.g. C<\*FILE>) to write to, and a string containing a column separator. The defaults, if arguments are not given are to print to STDOUT and use a single space as the column separator. The order does not matter, the method will determine whether an argument refers to a file or not. This is done so that one may call either
+
+ $pdl->export2d($fh);
+ $pdl->export2d(',');
+
+and it will do what you mean. Unfortunately this means that unlike C<wcols> one cannot use a filename rather than a filehandle; C<export2d> would interpret the string as the column separator!
+
+The method returns the number of columns that were written.
+
+=cut
+
 sub export2d {
   my ($pdl, $fh, $sep);
   $pdl = shift;
@@ -107,25 +171,4 @@ sub export2d {
 
 1;
 
-__END__
-__POD__
-
-=head1 NAME
-
-PDL::Util
-
-=head1 SYNOPSIS
-
- use PDL;
- use PDL::Util 'export2d';
-
- my $pdl = rvals(6,4);
 
- open my $fh, '>', 'file.dat';
- export2d($pdl, $fh);
-
-=head1 DESCRIPTION
-
-Convenient utility functions/methods for use with PDL.
-
-=cut

t/10-method.t → t/10-add_method.t

@@ -1,7 +1,7 @@
 use strict;
 use warnings;
 
-use Test::More tests => 3;
+use Test::More tests => 5;
 use PDL;
 use_ok('PDL::Util', 'add_pdl_method');
 
@@ -13,6 +13,10 @@ ok($pdl->can('mymethod_ref'), "method added by code reference");
 add_pdl_method({ 'mymethod_unroll' => 'unroll' });
 ok($pdl->can('mymethod_unroll'), "method added by name from PDL::Util's exportable function");
 
+add_pdl_method(['unroll', 'export2d']);
+ok($pdl->can('unroll'), "'unroll' method added by array from PDL::Util's exportable function");
+ok($pdl->can('export2d'), "'export2d' method added by array from PDL::Util's exportable function");
+
 sub method1 {
   my $pdl = shift;
   return 1;

t/25-import_method_array.t

@@ -0,0 +1,12 @@
+use strict;
+use warnings;
+
+use PDL;
+use Test::More tests => 3;
+
+use_ok('PDL::Util', ['unroll', 'export2d']);
+
+my $pdl = zeros(5,5);
+ok($pdl->can('unroll'), "'unroll' method imported during 'use'");
+ok($pdl->can('export2d'), "'export2d' method imported during 'use'");
+