Re: [FWP] From "The Art of Perl", Ch. 1

[Uri Guttman <uri@sysarch.com>]

>>>>> "JP" == Jeff Pinyan <jeffp@crusoe.net> writes:

  JP> Submissions I incorporate will be acknowledged.

damn right you will, you young whippersnapper! when i was your age i had
to program by punching out tiny holes in pieces of cardboard. you kids
are spoiled rotten with your pentiums and win2k super whiz systems! 

  JP> array-to-hash

  JP> 	while (($k,$v) = each %{{ @list }}){ ... }

slow as you have to build a hash just to get pairs. might as well copy
to a temp array and eat it with splice.

  JP> 	while ($i < @list){ ($k,$v) = @list[$i++,$i++]; ... }

the order and values if $i may surprise you. i have seen weird results
in perl with multiple side effect. better do that as

($k,$v) = @list[$i, $i + 1] ; $i +=2 ; }

  JP> slicing

  JP> 	@list = (somefunc())[1,4,6..9];

s/func/expression/;

  JP> hash things

  JP> 	@uniq{@list} = ();

good one to know

  JP> 	keys %{{ @tmp{@list} = () or %tmp }};

why do that when you either get the keys (which came from @list) or the
number of keys (also found in @list) depending on context? it looks
cuter than its functionality.

  JP> I'd like some more ideas for idioms.  Some of them might be ones
  JP> no one else has seen (I doubt anyone has used that last idiom I
  JP> put up there).  There are many commonly known ones that I've not
  JP> put up on this list, but mention them as well, just in case.

check out my hash slice tutorial. i have posted it to misc twice over
the last year or so. if you can't find it i will send it to you. it has
lots of idiomatic uses and examples of hash slices.

one day i want to expand that into a much longer article on hashes. i
have several section titles:

an associative array by any other name

from hashes to hashes

nothing's better than sliced hash


i have to much on my plate to even think about this. but i shall keep
dreaming.

uri


-- 
Uri Guttman  -----------------  SYStems ARCHitecture and Software Engineering
uri@sysarch.com  ---------------------------  Perl, Internet, UNIX Consulting
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"F**king Windows 98", said the general in South Park before shooting Bill.

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