in reply to Parsing barewords as sub/method calls?

This looks interesting but I do not fully understand.

You do not want to pre-declare also not to pollute the callers naming space. Does this mean that for the following code

BLA 1,2,3;
within_myDSL { BLA 1,2,3 }

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the first BLA should raise an error, whereas the second one would call AUTOLOAD?

That looks difficult to achieve.

I thought to move the pre-declaration into the package like this:

use subs qw( BLA );
package iDSL;
# package code
1;

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but that would pollute the callers space as well.

More generally, how would one define such an internal DSL, so that code like within_myDSL { >>different rules here<< } is possible?

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Re^2: Parsing barewords as sub/method calls?
by LanX (Saint) on Nov 23, 2013 at 18:25 UTC
    > That looks difficult to achieve.

    yeah not trivial, you need to temporarily redefine AUTOLOAD in the callers package:

    use strict;
use warnings;
use feature 'say';


package DSL;

our $AUTOLOAD;

sub within (&) {
  my $c_block=shift;
  
  #say
    my $call_pkg=((caller)[0]);

  # use B::Deparse;
  # say B::Deparse->new()->coderef2text($c_block);

  no warnings qw/redefine once/;
  no strict qw/refs/;
    
  local *{ ${call_pkg} . "::AUTOLOAD" } = 
     sub { say "Autoload called as $AUTOLOAD(@_)" };

  $c_block->();
  
}



package TEST;

DSL::within {
  &BLA;
  BLUB(2,3,4);
};

#  with import
sub within (&);
*within=\&DSL::within;

within {
  &BLAi;
  BLUBi(2,3,4);
};



BLX();

  
__END__
Autoload called as TEST::BLA()
Autoload called as TEST::BLUB(2 3 4)
Autoload called as TEST::BLAi()
Autoload called as TEST::BLUBi(2 3 4)
Undefined subroutine &TEST::BLX called at /home/lanx/perl/exp/DSL.pl l
+ine 48.

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    Cheers Rolf

    ( addicted to the Perl Programming Language)

    updates

    code extended

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[d/l]

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