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Function std.algorithm.comparison.levenshteinDistance

Returns the Levenshtein distance between s and t. The Levenshtein distance computes the minimal amount of edit operations necessary to transform s into t. Performs Ο(s.length * t.length) evaluations of equals and occupies Ο(s.length * t.length) storage.

Prototype

size_t levenshteinDistance(alias equals, Range1, Range2)(
  Range1 s,
  Range2 t
)
if (isForwardRange!Range1 && isForwardRange!Range2);

Parameters

NameDescription
equals The binary predicate to compare the elements of the two ranges.
s The original range.
t The transformation target

Returns

The minimal number of edits to transform s into t.

Does not allocate GC memory.

Example

import std.algorithm.iteration : filter;
import std.uni : toUpper;

assert(levenshteinDistance("cat", "rat") == 1);
assert(levenshteinDistance("parks", "spark") == 2);
assert(levenshteinDistance("abcde", "abcde") == 0);
assert(levenshteinDistance("abcde", "abCde") == 1);
assert(levenshteinDistance("kitten", "sitting") == 3);
assert(levenshteinDistance!((a, b) => std.uni.toUpper(a) == std.uni.toUpper(b))
    ("parks", "SPARK") == 2);
assert(levenshteinDistance("parks".filter!"true", "spark".filter!"true") == 2);
assert(levenshteinDistance("ID", "I♥D") == 1);

Authors

Andrei Alexandrescu

License

Boost License 1.0.

Comments