#34 build-time (static) NiceSlice support for PDL installs


PDL::NiceSlice is very convenient in that it allows a more
natural array-style pdl element and slice addressing
syntax. The downside is that it's use of a perl source
filter makes "NiceSlice Perl" not valid Perl.

This can cause problems in two ways: (1) the NiceSlice
filter might modify a detect a plain perl construct as a
slicing one and filter the code instead of allowing it to
pass, and (2) perl runtime environments might not support
the use of source filters as indicated in the following
report below to the perldl mailing list.

For portability and robustness of PDL, it is needed
that the PDL core modules be as much portable perl
as possible. One possibility would be to remove
NiceSlice constructs from the PDL core sources in
preference for the ->slice() ones. That can be done
in the near term.

In the longer term, I propose that we add a
build-time NiceSlice processing step to the PDL
install process. The result of this would be the
same module files as currently, just that the
PDL::NiceSlice constructs would already be
source-filtered leaving "pure perl" only for the
blib/ install files.

On 9/23/2010 9:00 AM, Sacha Fouchard wrote:
> Hello everybody,
> This is my problem that could be interesting for many of you.
> When I try to use PDL in a prog source and create an executable with
> Activestate perlapp, I 've got the following error after compilation, at
> run time (The exe is correctly created).
> When I launch the prog, it says:
> syntax error at /<C:\prog.exe>PDL/MatrixOps.pm line 444, near "0:"
> syntax error at /<C:\prog.exe>PDL/MatrixOps.pm line 449, near "1:"
> syntax error at /<C:\prog.exe>PDL/MatrixOps.pm line 450, near "0:"
> syntax error at /<C:\prog.exe>PDL/MatrixOps.pm line 827, near "2:"
> For example, line 443 in MatrixOps.pm is :
> determinant( $a->(0:$i-1,1:-1)->append( $a->($i+1:-1,1:-1 ) ) );
> The pb seems to come from niceslicing syntax.
> But, if I run the prog directly under the shell, it works perfectly.
> What's happening?
> Try a prog with nothing but only "use PDL", compile it run, and see.
> I found 12 lines with problems in MatrixOps.pm.
> I use perl 5.10 x86 and the lastest PDL from CPAN (2.4.7) on win 7 x64.
> The problem was the same under vista 32 with perl 5.10 and PDL 2.4.6.
> Thank you all,
> Sacha


  • Chris Marshall

    Chris Marshall - 2010-09-25

    A quick review of the .pm files in the PDL build that 'use PDL::NIceSlice'
    results as follows:

    PDL/AutoLoader.pm # has line to use for prefiltering

    PDL/IO/Dumper.pm # commented out use PDL::NiceSlice

    PDL/NiceSlice.pm # duh!

    PDL/Graphics/PGPLOT/Window.pm # uses PDL::NiceSlice
    PDL/Graphics2D.pm # uses PDL::NiceSlice
    PDL/IO/FITS.pm # uses PDL::NiceSlice
    PDL/MatrixOps.pm # uses PDL::NiceSlice
    PDL/Perldl2/Plugin/NiceSlice.pm # uses PDL::NiceSlice
    PDL/Transform.pm # uses PDL::NiceSlice
    PDL/Transform/Cartography.pm # uses PDL::NiceSlice
    PDL/Transform/Proj4.pm # uses PDL::NiceSlice

    And I notice that the PDL::AutoLoader module has a line in it
    for the import routine that is pretty much the desired pre-filter
    form of PDL::NiceSlice. All that needs to be done is wrap it
    up in a script that can be used manually or part of the PDL build
    and install process.

  • Chris Marshall

    Chris Marshall - 2010-09-25

    perldlpp pre-processor script

  • Chris Marshall

    Chris Marshall - 2010-09-25

    I've attached a simple perldlpp pre-processor script to this
    ticket based on the code in PDL/AutoLoader.pm. It can
    be used to filter out the NiceSlice calls in a PDL install
    (the files listed in the previous comment) so that the source
    filter is not needed. That should enable a perlapp to be
    built. Good luck. I've added the code to this comment so
    folks can cut and paste from their browser if desired.


    use PDL::NiceSlice;
    my $prefile = "";
    local $/;
    $prefile = <>;
    my ($postfile) = &PDL::NiceSlice::perldlpp("PDL::NiceSlice", $prefile);
    print $postfile;

  • Chris Marshall

    Chris Marshall - 2010-09-26

    The perldlpp.pl script takes as command line argument(s)
    the file to filter for PDL::NiceSlice constructs. It outputs the
    result to STDOUT:

    On unixen:
    perldlpp.pl file-w-niceslice.pm > clean-file.pm

    Or on win32:
    perl perldlpp.pl file-w-niceslice.pm > clean-file.pm

  • Chris Marshall

    Chris Marshall - 2010-10-03

    I've added perldlpp.pl to the utils/ directory of the PDL git
    and it should be available there in the next CPAN release.
    The script is not installed anywhere during a build but it
    is there if you wish to use it.

  • Chris Marshall

    Chris Marshall - 2010-11-03

    I recently looked at the perl .pmc file format
    which hsa been reinvigorated for perl6 to perl5
    translation via Module::Compile. A natural
    location for the pre-converted NiceSlice code
    would be in the corresponding .pmc file.

    Conveniently, Module::Compile already
    handles the problem of skipping POD lines
    during the source filtering.

  • Chris Marshall

    Chris Marshall - 2011-06-08

    Follow up on related PDL::NiceSlice work. Experimental refactoring
    of PDL::NiceSlice to use Filter::Simple appears very promising.
    Unfortunately, it does not appear that Module::Compile is compatible
    with Filter::Simple. In order to proceed with this approach, the two
    modules will need to be reconciled somehow.

  • Chris Marshall

    Chris Marshall - 2013-01-02

    I anticipate that the PDL::NiceSlice filter re-work will enable this functionality as well. Bumping priority to match.

  • Chris Marshall

    Chris Marshall - 2013-01-02
    • priority: 5 --> 7
    • assigned_to: nobody --> marshallch

Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:

No, thanks