The document discusses hacking on the perl5 programming language. It mentions Devel::PPAP, a way to start playing with the perl parser. It also discusses optimizing perl code by improving syntax for initializing hashes in fewer lines of code, which required changes to the perl tokenizer and C preprocessor. The document encourages hacking on the perl5 core to improve and extend the language.

1. A
road to hacking on
perl5
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2. From a challenge
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3. Devel::PPAP
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4. ●May fail to compile
●5.16.x only
●Incomplete
●Way to start playing
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5. Since
● shift; # w/o argument
● delete $hash{'const'};
● $tied{foo}
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6. Failed optimisation
●10+ commits
●Better code
●Corner case fixes
●Tests
●Bit faster afterall
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7. my %r =
map { $_ => $h{$_} }
'a', 'b', 'c'
;
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8. my %r = (
a => $h{'a'},
b => $h{'b'},
...
);
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9. my %r = %h{'a', 'b', 'c'};
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10. OMG!
I'm changing Perl
syntax...
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11. ●11 loc in toke.y
●48 loc in pp.c
●proof in 4 hours
●comes in 5.20
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12. perl5 core is NOT that
complex
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13. Let's make perldelta
that MAKES
DIFFERENCE
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