Re^4: Recap: The Future of Perl 5

It's built into the perl executable itself:

BEGIN { %Foo::FIELDS = qw(a 1 b 1) };
my Foo $x = {};
$x->{c} = 1; # compile-time error
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fields.pm just populates the field hash

Dave.

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Re^5: Recap: The Future of Perl 5 by tobyink (Canon) on Aug 24, 2018 at 12:30 UTC
Interesting. I guess this explains the limitation with Lexical::Types where it allows you to define, say, `my Str $x` to do something else other than check `$x` is a blessed Str object (and I've started to explore that possibility using Lexical::TypeTiny), but still requires there to be a Str package defined. I guess Perl needs that package to exist so that it can look for `%FIELDS`. toby döt ink	[reply] [d/l] [select]

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Re^5: Recap: The Future of Perl 5
by tobyink (Canon) on Aug 24, 2018 at 12:30 UTC

Interesting. I guess this explains the limitation with Lexical::Types where it allows you to define, say, my Str $x to do something else other than check $x is a blessed Str object (and I've started to explore that possibility using Lexical::TypeTiny), but still requires there to be a Str package defined. I guess Perl needs that package to exist so that it can look for %FIELDS.

toby döt ink

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