jdiff
public class DiffMyers extends Object
change
objects which form an
edit script. The objects compared are traditionally lines
of text from two files. Comparison options such as "ignore
whitespace" are implemented by modifying the equals
and hashcode
methods for the objects compared.
The basic algorithm is described in: "An O(ND) Difference Algorithm and its Variations", Eugene Myers, Algorithmica Vol. 1 No. 2, 1986, p 251.
This class outputs different results from GNU diff 1.15 on some inputs. Our results are actually better (smaller change list, smaller total size of changes), but it would be nice to know why. Perhaps there is a memory overwrite bug in GNU diff 1.15.
Nested Class Summary | |
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static class | DiffMyers.change The result of comparison is an "edit script": a chain of change objects.
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Field Summary | |
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boolean | heuristic When set to true, the comparison uses a heuristic to speed it up.
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boolean | no_discards When set to true, the algorithm returns a guarranteed minimal
set of changes. |
Constructor Summary | |
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DiffMyers(Object[] a, Object[] b) Prepare to find differences between two arrays. |
Method Summary | |
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DiffMyers.change | diff_2(boolean reverse) |
equals
. The original Object arrays
are no longer needed for computing the differences. They will
be needed again later to print the results of the comparison as
an edit script, if desired.