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PDL::AutoLoader - MatLab style AutoLoader for PDL
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$a = func1(...); # Load file func1.pdl
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$b = func2(...); # Load file func2.pdl
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$PDL::AutoLoader::Rescan = 1; # Enable re-scanning
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This module implements a MatLab style AutoLoader for PDL. If a unknown
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function 'func()' is called then a file 'func.pdl' is searched for and
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if found is read in to define 'func()' which is then executed.
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Files are seached for using the directories in seach path C<@PDLLIB>, which
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is initialised from the shell environment variable C<PDLLIB> which is a
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colon seperated list of directories.
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setenv PDLLIB "/home/kgb/pdllib:/local/pdllib"
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Note this is kept seperate from C<PERL5LIB> just in case.
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As an added bonus, you can use a leading '+' on a directory name to
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search not just that directory but the entire directory tree under it
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(excluding symlinks). The subdirs are determined by explicit search,
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and searches occur at startup and again each time you change the number
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of elements in @PDLLIB.
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setenv PDLLIB "+~kgb/PDL"
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will search /home/kgb/PDL and all its subdirectories for .pdl files.
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The variable C<$PDL::AutoLoader::Rescan> controls whether files
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are automatically re-scanned for changes at the C<perldl> command
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If C<$PDL::AutoLoader::Rescan == 1> and the file is changed
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then the new definition is reloaded auto-matically before
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executing the C<perldl> command line. Which means in practice
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you can edit files, save changes and have C<perldl> see the
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changes automatically.
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The default is '0' - i.e. to have this feature disabled.
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As this feature is only pertinent to the C<perldl> shell it imposes
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no overhead on PDL scripts. Yes Bob you can have your cake and
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Note: files are only re-evaled if they are determined to have
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been changed according to their date/time stamp.
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No doubt this interface could be improved upon some more. :-)
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sub foo { # file 'foo.pdl' - define the 'foo' function
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return sqrt($x**2 + $x**3 + 2);
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1; # File returns true (i.e. loaded successfully)
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Copyright(C) 1997 Karl Glazebrook (kgb@aaoepp.aao.gov.au).
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All rights reserved. There is no warranty. You are allowed
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to redistribute this software / documentation under certain
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conditions. For details, see the file COPYING in the PDL
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distribution. If this file is separated from the PDL distribution,
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the copyright notice should be included in the file.
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No doubt this interface could be improved upon some more. :-)
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Will probably be quite slow if C<$PDL::AutoLoader::Rescan == 1>
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and thousands of functions have been autoloaded.
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There could be a race condition in which the file changes
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while the internal autoloader code is being executed but it
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Probably has not been tested enough!
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@PDLLIB = (".",split(':',$ENV{"PDLLIB"})) if defined $ENV{"PDLLIB"};
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$PDL::AutoLoader::Rescan=0;
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%PDL::AutoLoader::FileInfo = ();
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# Code to reload stuff if changed
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sub PDL::AutoLoader::reloader {
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return unless $PDL::AutoLoader::Rescan;
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# Now check functions and reload if changed
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for my $func (keys %PDL::AutoLoader::FileInfo) {
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($file, $old_t) = @{ $PDL::AutoLoader::FileInfo{$func} };
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if ( (stat($file))[9]>$old_t ) { # Reload
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print "Reloading $file as file changed...\n" if $PDL::verbose;
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&PDL::AutoLoader::autoloader_do($file);
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$PDL::AutoLoader::FileInfo{$func} = [ $file, (stat($file))[9] ];
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sub PDL::AutoLoader::import {
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my $pkg = (caller())[0];
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my $toeval = "package $pkg;\n";
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# Make sure that the eval gets NiceSlice if we have it in this level
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# (it's a drag that preprocessors aren't transitive...)
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$toeval .= "use PDL::NiceSlice;\n" if(defined $PDL::NiceSlice::VERSION);
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push @PERLDL::AUTO, \&PDL::AutoLoader::reloader;
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$AUTOLOAD =~ /::([^:]*)$/;
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# Trap spurious calls from 'use UnknownModule'
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goto &$AUTOLOAD if ord($func)==0;
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# Check if the PDLLIB needs to be expanded and, if so, expand it.
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# This only updates when PDLLIB changes size, which should be OK
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# for most things but doesn't catch new directories in expanded
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# directory trees. It seems like an OK compromise between never
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# catching anything and always thrashing through the directories.
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if($PDLLIB_CT != scalar(@PDLLIB)) {
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print "Expanding directories from ".join(':',@PDLLIB)."...\n"
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$PDLLIB_CT = scalar(@PDLLIB);
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foreach $_(@PDLLIB) {
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# Expand ~{name} and ~ conventions
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s/^(\+?)~([a-zA-Z0-9]*)// &&
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($_ = $1.((getpwnam($2 || getlogin))[7]).$_ );
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# If there's a leading '+', include all subdirs too.
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push(@PDLLIB_EXPANDED,
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s/^\+// ? &PDL::AutoLoader::expand_dir($_) : $_
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print "Loading $func.pdl...\n" if $PDL::verbose;
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for my $dir (@PDLLIB_EXPANDED) {
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my $file = $dir . "/" . "$func.pdl";
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PDL::AutoLoader::autoloader_do($file);
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# Remember autoloaded functions and do some reasonably
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# smart cacheing of file/directory change times
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if ($PDL::AutoLoader::Rescan) {
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$PDL::AutoLoader::FileInfo{$func} = [ $file, (stat($file))[9] ];
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# Now go to the autoloaed function
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goto &$AUTOLOAD unless $@;
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die "PDL autoloader: Undefined subroutine $func() cannot be AutoLoaded\n";
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# Simple 'do' doesn't work with preprocessing -- this replaces
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# "do file" and sticks NiceSlice in manually if it's needed (yuck).
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sub PDL::AutoLoader::autoloader_do {
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if(defined($PDL::NiceSlice::VERSION)) {
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print "AutoLoader: NiceSlice enabled...\n" if($PDL::debug);
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if(open(AUTOLOAD_FILE,"<$file")) {
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my($script) = &PDL::NiceSlice::perldlpp(join("",<AUTOLOAD_FILE>));
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print "AutoLoader: no NiceSlice...\n" if($PDL::debug);
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# Expand directories recursively...
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sub PDL::AutoLoader::expand_dir {
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if(! -d $dir) { return undef; }
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@subdirs = grep((!m/^\./ && ($_="$dir/$_") && (-d $_)), readdir(FOO));
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while(defined ($d = shift @subdirs)) {
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push(@list,&PDL::AutoLoader::expand_dir($d));
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;# Exit with OK status
added
removed
Basic/AutoLoader.pm
