| 1 | NAME |
1 | NAME |
| 2 | Array::Heap - treat perl arrays as heaps (priority queues) |
2 | Array::Heap - treat perl arrays as binary heaps/priority queues |
| 3 | |
3 | |
| 4 | SYNOPSIS |
4 | SYNOPSIS |
| 5 | use Array::Heap; |
5 | use Array::Heap; |
| 6 | |
6 | |
| 7 | DESCRIPTION |
7 | DESCRIPTION |
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… | |
| 113 | will sort according to the first element of the arrays, i.e. "1,2,3". |
113 | will sort according to the first element of the arrays, i.e. "1,2,3". |
| 114 | |
114 | |
| 115 | The custom comparison functions work similar to how "sort" works: $a and |
115 | The custom comparison functions work similar to how "sort" works: $a and |
| 116 | $b are set to the elements to be compared, and the result should be |
116 | $b are set to the elements to be compared, and the result should be |
| 117 | greater than zero then $a is greater than $b, 0 otherwise. This means |
117 | greater than zero then $a is greater than $b, 0 otherwise. This means |
| 118 | that you cna use the same function as for sorting the array, but you |
118 | that you can use the same function as for sorting the array, but you |
| 119 | could also use a simpler function that just does "$a > $b". |
119 | could also use a simpler function that just does "$a > $b". |
| 120 | |
120 | |
| 121 | The first example above corresponds to this comparison "function": |
121 | The first example above corresponds to this comparison "function": |
| 122 | |
122 | |
| 123 | { $a <=> $b } |
123 | { $a <=> $b } |
| … | |
… | |
| 150 | |
150 | |
| 151 | * This module can leak memory (or worse) when your comparison function |
151 | * This module can leak memory (or worse) when your comparison function |
| 152 | exits unexpectedly (e.g. "last") or throws an exception, so do not |
152 | exits unexpectedly (e.g. "last") or throws an exception, so do not |
| 153 | do that. |
153 | do that. |
| 154 | |
154 | |
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155 | SEE ALSO |
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156 | This module has a rather low-level interface. If it seems daunting, you |
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157 | should have a look at Array::Heap::ModifiablePriorityQueue, which is |
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158 | based on this module but provides more and higher-level operations with |
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159 | an object-oriented API which makes it harder to make mistakes. |
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160 | |
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161 | A slightly less flexible (only numeric weights), but also slightly |
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162 | faster variant of that module can be found as |
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163 | Array::Heap::PriorityQueue::Numeric on CPAN. |
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164 | |
| 155 | AUTHOR AND CONTACT INFORMATION |
165 | AUTHOR AND CONTACT INFORMATION |
| 156 | Marc Lehmann <schmorp@schmorp.de> |
166 | Marc Lehmann <schmorp@schmorp.de> |
| 157 | http://software.schmorp.de/pkg/Array-Heap |
167 | http://software.schmorp.de/pkg/Array-Heap |
| 158 | |
168 | |
