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

[Eli Evans <eevans@libronix.com>]

Quoth Jeff Pinyan [mailto:jeffp@crusoe.net]:
:
: I'm looking for some idioms for dealing with arrays, hashes, 
: and unnamed
: lists.  For more information on "The Art of Perl", visit:
: 
: 	http://magneton-59.dynamic.rpi.edu/book/
: 
: Submissions I incorporate will be acknowledged.

Please don't. :-)

: Operating on Lists
: ------------------
: 
: array-to-hash
: 
: 	while (($k,$v) = each %{{ @list }}){ ... }
: 	while ($i < @list){ ($k,$v) = @list[$i++,$i++]; ... }

	# obvious
	%hash = @array;
	
	# Some silly ways to get similar results (build %hash from @array)

	# Silly idiom no. 1
	for($i = $[; $i <= $#array; $i++)
		{
		($i % 2) and $hash{$array[$i-1]} = $array[$i];
		}

	# Corollary to silliy idiom no. 1
	for($i = $[; $i <= $#array; $i++)
		{
		!($i % 2) and $hash{$array[$i]} = $array[$i+1];
		}
	
	# Silly idiom no. 2
	@hash{ grep{$i++;$i % 2} @array } = grep{$j++;not $j % 2} @array;

	# Silly idiom no. 3
	for($i = $[; $i <= $#array; $i+=2)
		{
		$hash{$array[$i]} = $array[$i+1];
		}

	# Silly idiom no. 4
	%hash = map{ $i++; ($i % 2) and ($k => $_); $k = $_ } @array;

	# Lastly, do it real stupid and hose @array
	while(@array)
		{
		$hash{pop @array} = pop @array;
		}	

That's all the fun I can stand for today; my ride is here.

Eli
________________________
Eli Evans
Text Preparation Manager
Libronix Corp.
mailto:eli@libronix.com
http://www.libronix.com
Ec 12:12; Jn 21:22



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