Hi Liz, this is my attempt at decoding this clever JAPH, in fact my first attempt at decoding any JAPH, so please correct (and forgive) my analysis if wrong! 

@; = (491036,8051555,4785250,3341086,912133,189089,691108);

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# This is just an eye candy, an array placeholder of 7 elements
%; = qw/
       He
       didn't,Just
       do
       to,Perl
       didn't
       understand,another
       it
       would,hacker!
       /;

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# This constructs the %; hash variable with 4 entries, namely He, do, didn't, it:
  He => didn't,Just
  do => do,perl
  didn't => understand,another
  it => would, hacker!

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%: = qw/
================================= ==================================
Randal said it would be tough to do in sed.  He didn't say he didn't
understand sed.  Randal understands sed quite well.  Which is why he
uses Perl.   :-)     -- Larry Wall in <7874@jpl-devvax.JPL.NASA.GOV>
================================= ==================================
    /;

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This builds another hash lookup - %:
{ # required by redo, where to start for the redo
    /./ ? eval(join 't, ', qw:prin exi delphi:) : /./;

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This is really (translated to):
    /./ ? { print, exit, delphit, } : /./;

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or just
    /./ ? { print, exit, } : /./;

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Clever, the first time this loop is enterred, $_ is undef, so the print and exit is not performed. delphit would have no effect (after the exit).
    $:{do} = 'to';

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# Another clever bit, insert the required 'do=>to' lookup pair into the hash table. How this is used will be explored later. 
    @; = map { join ',', '', $_, '' } values(%;);

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Translates the values to the %; hash to ",xxx,", required by the lookup below
This translation is clever:
The key-value pairs in the %: hash so far
    He => didn't
    didn't => understand
    do => to  # manually inserted before
    it => would

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And then... Modify the hash table %:, with values from the %; lookup.
    eval '$:{q?'.$_.'?}=~s'.shift@; for keys(%;);

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So that:
   He => Just
   didn't => another
   do => Perl
   it => Hacker!

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This next bit just creates the string to be printed. :-)
    $_ = qq{@{[@:{qw{ He didn't do it }}]}};

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The next bit goes back to the beginning of the loop, with $_ set to "Just another Perl hacker!", and of cause the print, exit, code will take over from there... 
    redo } x:

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In reply to Re: Pe(a)rls in line noise by Roger
in thread Pe(a)rls in line noise by liz

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