PDL::Lvalue - declare PDL lvalue subs

PDL documentation Contained in the PDL distribution.

Index

Code Index:

NAME

Top

PDL::Lvalue - declare PDL lvalue subs

DESCRIPTION

Top

Declares a subset of PDL functions so that they can be used as lvalue subs. In particular, this allows simpler constructs such as

  $a->slice(',(0)') .= 1;

instead of the clumsy

  (my $tmp = $a->slice(',(0)')) .= 1;

This will only work if your perl supports lvalue subroutines (i.e. versions >= v5.6.0). Note that lvalue subroutines are currently regarded experimental.

SYNOPSIS

Top

 use PDL::Lvalue; # automatically done with all PDL loaders

FUNCTIONS

Top

subs

test if routine is a known PDL lvalue sub

  print "slice is an lvalue sub" if PDL::Lvalue->subs('slice');

returns the list of PDL lvalue subs if no routine name is given, e.g.

  @lvfuncs = PDL::Lvalue->subs;

It can be used in scalar context to find out if your PDL has lvalue subs:

  print 'has lvalue subs' if PDL::Lvalue->subs;

AUTHOR

Top

Copyright (C) 2001 Christian Soeller (c.soeller@auckland.ac.nz). All rights reserved. There is no warranty. You are allowed to redistribute this software / documentation under certain conditions. For details, see the file COPYING in the PDL distribution. If this file is separated from the PDL distribution, the copyright notice should be included in the file.

PDL documentation Contained in the PDL distribution. 
package PDL::Lvalue;

# list of functions that can be used as lvalue subs
# extend as necessary
my @funcs = qw/slice mslice nslice index where px diagonal clump
  dummy index2d dice dice_axis xchg mv flat sever polyfillv range rangeb 
  indexND indexNDb reshape/;

my $prots = join "\n", map {"use attributes 'PDL', \\&PDL::$_, 'lvalue';"}
  @funcs;


sub subs {
  my ($type,$func) = @_;
  if (defined $func) {
    $func =~ s/^.*:://;
    return ($^V and $^V >= 5.006007) && scalar grep {$_ eq $func} @funcs;
  } else {
    return ($^V and $^V >= 5.006007) ? @funcs : ();
  }
}

# print "defining lvalue subs:\n$prots\n";

eval << "EOV" if ($^V and $^V >= 5.006007);
{package PDL;
$prots
}
EOV


1;