Define-or isn't always correctly picked up

[Leont]

Define-or isn't always correctly picked up

[zmughal]

Yep, that's because of Try::Tiny's subs conflicting with the PPR built-in rule for feature 'try' so PPR's regex thinks the whole file is invalid Perl.

You have to remove that rule from the grammar to fix it (DCONWAY mentions this in the docs for PPR). This is how I did that with a role:

• https://github.com/zmughal-experiment/perl-parsing-panoply/blob/main/lib/PPP/Babble/Grammar/Role/TryTiny.pm,
• https://github.com/zmughal-experiment/perl-leaning-toothpick-of-babble/blob/v0.0.3/dist-zilla.ini#L24-L25.

In my own code where I'm using the [Babble] plugin, it was easier to rename
try to try_tt:

use Import::Into;
use Importer ();
use Try::Tiny ();

sub import {
	my $target = caller;

	# Use postfix so that PPR does not need modification relative to the
	# built-in feature 'try'.
	Importer->import_into('Try::Tiny', $target, (
		map {
			$_ => { -postfix => '_tt' },
		} qw(try catch finally)
	));
}

but I don't necessarily recommend that for others (unless they might be doing a refactor).

[Leont]

Yep, that's because of Try::Tiny's subs conflicting with the PPR built-in rule for feature 'try' so PPR's regex thinks the whole file is invalid Perl.

I don't think it's because of that; even on my feature-try branch I'm observing this issue.

[zmughal]

Yep, that's because of Try::Tiny's subs conflicting with the PPR built-in rule for feature 'try' so PPR's regex thinks the whole file is invalid Perl.

I don't think it's because of that; even on my feature-try branch I'm observing this issue.

You're right. In my test code, I got the transformation as a side-effect of
running the ::DefinedOr plugin twice. :-P I need to figure out why it isn't finding it in a single pass.

---

for PASSES in $(seq 2); do
  for T in 6.029 fct; do
    git -c advice.detachedHead=false co $T ;
    diff lib/Dist/Zilla.pm <(perl -I $(got-path-for-name-match /perl-parsing-panoply$)/lib -Mutf8::all -MBabble::Grammar -MWith::Roles -MBabble::PluginChain -MPath::Tiny -E '
      my $src = path(shift @ARGV)->slurp_utf8; my $passes = shift @ARGV;
      my $pc = Babble::PluginChain->new( grammar => Babble::Grammar->with::roles( $src =~ /use Try::Tiny/s ? q(PPP::Babble::Grammar::Role::TryTiny) : () )->new );
      $pc->add_plugin($_) for qw(::DefinedOr) x $passes;
      say $pc->transform_document( $src )'  lib/Dist/Zilla.pm $PASSES );
  done;
done

gives the output:

HEAD is now at cba51b6d v6.029
444c444
<     return( $year // (localtime)[5] + 1900 );
---
>     return( (map +(defined($_) ? $_ : (localtime)[5]), $year)[0] + 1900 );
885a886
> 
Previous HEAD position was cba51b6d v6.029
Switched to branch 'fct'
Your branch is up to date with 'Leont/fct'.
444c444
<     return( $year // (localtime)[5] + 1900 );
---
>     return( (map +(defined($_) ? $_ : (localtime)[5]), $year)[0] + 1900 );
887a888
> 
HEAD is now at cba51b6d v6.029
444c444
<     return( $year // (localtime)[5] + 1900 );
---
>     return( (map +(defined($_) ? $_ : (localtime)[5]), $year)[0] + 1900 );
617c617
<                     . ($self->VERSION // '(undef)'),
---
>                     . ((map +(defined($_) ? $_ : '(undef)'), $self->VERSION)[0]),
885a886
> 
Previous HEAD position was cba51b6d v6.029
Switched to branch 'fct'
Your branch is up to date with 'Leont/fct'.
444c444
<     return( $year // (localtime)[5] + 1900 );
---
>     return( (map +(defined($_) ? $_ : (localtime)[5]), $year)[0] + 1900 );
619c619
<                     . ($self->VERSION // '(undef)'),
---
>                     . ((map +(defined($_) ? $_ : '(undef)'), $self->VERSION)[0]),
887a888
> 

[zmughal]

Oh, and the first example is wrong because no precedence parsing:

<     return( $year // (localtime)[5] + 1900 );
---
>     return( (map +(defined($_) ? $_ : (localtime)[5]), $year)[0] + 1900 );

is wrong because + is higher precedence than //.

$ perl -MO=Deparse,-p -e ' ( $year // (localtime)[5] + 1900 ) '
($year // (((localtime))[5] + 1900));
-e syntax OK