Re: [FWP] Closest hash value

[Ronald J Kimball <rjk@linguist.dartmouth.edu>]

On Fri, Jul 16, 1999 at 01:00:21PM -0500, Edward M. Perry wrote:
> 
> Here is the problem: given a key ($key), and a hash (%h), I want the value
> of the closest hash key. I came up with this which is only moderately fun.
> Really it works pretty well, assuming keys are numeric and the hash is
> small. Mapping to %temp is weak.  
> 
> An array seems unreasonable because in reality the keys (or indicies) are
> large and the array would be very sparse.
> 
> $key  = 5;
> %h    = (1=>'one', 2=>'two', 4=>'four', 8=>'eight');
> 
> %temp = map { abs($_-$key) => $_ } keys %h;
> $val  = $h{$temp{(sort({$a<=>$b} keys %temp))[0]}};
> 
> Any ideas?
> 

You don't need %temp; just sort directly.

$val = (sort {abs($a - $key) <=> abs($b - $key)} keys %h)[0];

Of course, you could use an Orcish Maneuver or a Schwartzian Transform for
the sort if you wanted.

Ronald

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