Tie::Hash::Rank(U3s)er Contributed Perl DocumentatiToine::Hash::Rank(3)
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Tie::Hash::Rank - A hash which turns values into ranking
positions
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use Tie::Hash::Rank
tie my %ranks, 'Tie::Hash::Rank';
%ranks=(
Adams => 78,
Davies => 35,
Edwards => 84,
Thomas => 47
);
print $ranks{Adams};
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This module allows you to tie a hash such that when you
retrieve values from it, you get the value's rank instead
of the actual data. By default, it ranks items
numerically, with the highest value getting rank 1, and
given two equal values they will also get the same rank.
The following named parameters are supported:
""ALGORITHM""
Use "ALGORITHM" to sort items prior to ranking them.
The default is a reverse-numeric sort. Specify it
thus $DATA{$a} <=> $DATA{$b} to do a normal numeric
sort. Divining how to do other types of sort is left
as a trivial exercise for the reader. See perldoc -f
sort.
""EQUALITYSUFFIX""
Append "EQUALITYSUFFIX" to the rank of items with
equal rank. The default is to have no EQUALITYSUFFIX,
but a common alternative would be an "=" sign.
""EQUALITYPREFIX""
Prepend "EQUALITYPREFIX" to the rank of items with
equal rank. The default is to have no EQUALITYPREFIX,
but a common alternative would be an "=" sign.
""RECALCULATE""
Can be either "onstore" or "onfetch", and defaults to
'onstore'. This determines when the module
recalculates the ranks. 'onstore' makes it
recalculate whenever you add a value to the hash, and
'onfetch' whenever you retrieve a value. Use this
option if you need to tune your hash for data which is
mainly read or mainly written, although it will make
very little difference for small data-sets.
2001-06-13 perl v5.6.1 1
Tie::Hash::Rank(U3s)er Contributed Perl DocumentatiToine::Hash::Rank(3)
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Plenty, no doubt. Please tell me if you find any.
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David Cantrell <david@cantrell.org.uk>
This module originated as a grotesquely over-engineered
answer to a trivial question posed by Simon Cozens as an
example of something you might want to ask when testing
someone's perl skillz. An earlier - and less complete -
version of this module was posted on the London Perl
Mongers mailing list.
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Copyright 2001 David Cantrell.
This module is licensed under the same terms as perl
itself.
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_T_i_e_:_:_H_a_s_h(3)
2001-06-13 perl v5.6.1 2