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author | Minteck <contact@minteck.org> | 2023-01-10 14:54:04 +0100 |
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committer | Minteck <contact@minteck.org> | 2023-01-10 14:54:04 +0100 |
commit | 99c1d9af689e5325f3cf535c4007b3aeb8325229 (patch) | |
tree | e663b3c2ebdbd67c818ac0c5147f0ce1d2463cda /school/node_modules/fast-levenshtein/levenshtein.js | |
parent | 9871b03912fc28ad38b4037ebf26a78aa937baba (diff) | |
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Update - This is an automated commit
Diffstat (limited to 'school/node_modules/fast-levenshtein/levenshtein.js')
-rw-r--r-- | school/node_modules/fast-levenshtein/levenshtein.js | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/school/node_modules/fast-levenshtein/levenshtein.js b/school/node_modules/fast-levenshtein/levenshtein.js new file mode 100644 index 0000000..dbe3628 --- /dev/null +++ b/school/node_modules/fast-levenshtein/levenshtein.js @@ -0,0 +1,136 @@ +(function() { + 'use strict'; + + var collator; + try { + collator = (typeof Intl !== "undefined" && typeof Intl.Collator !== "undefined") ? Intl.Collator("generic", { sensitivity: "base" }) : null; + } catch (err){ + console.log("Collator could not be initialized and wouldn't be used"); + } + // arrays to re-use + var prevRow = [], + str2Char = []; + + /** + * Based on the algorithm at http://en.wikipedia.org/wiki/Levenshtein_distance. + */ + var Levenshtein = { + /** + * Calculate levenshtein distance of the two strings. + * + * @param str1 String the first string. + * @param str2 String the second string. + * @param [options] Additional options. + * @param [options.useCollator] Use `Intl.Collator` for locale-sensitive string comparison. + * @return Integer the levenshtein distance (0 and above). + */ + get: function(str1, str2, options) { + var useCollator = (options && collator && options.useCollator); + + var str1Len = str1.length, + str2Len = str2.length; + + // base cases + if (str1Len === 0) return str2Len; + if (str2Len === 0) return str1Len; + + // two rows + var curCol, nextCol, i, j, tmp; + + // initialise previous row + for (i=0; i<str2Len; ++i) { + prevRow[i] = i; + str2Char[i] = str2.charCodeAt(i); + } + prevRow[str2Len] = str2Len; + + var strCmp; + if (useCollator) { + // calculate current row distance from previous row using collator + for (i = 0; i < str1Len; ++i) { + nextCol = i + 1; + + for (j = 0; j < str2Len; ++j) { + curCol = nextCol; + + // substution + strCmp = 0 === collator.compare(str1.charAt(i), String.fromCharCode(str2Char[j])); + + nextCol = prevRow[j] + (strCmp ? 0 : 1); + + // insertion + tmp = curCol + 1; + if (nextCol > tmp) { + nextCol = tmp; + } + // deletion + tmp = prevRow[j + 1] + 1; + if (nextCol > tmp) { + nextCol = tmp; + } + + // copy current col value into previous (in preparation for next iteration) + prevRow[j] = curCol; + } + + // copy last col value into previous (in preparation for next iteration) + prevRow[j] = nextCol; + } + } + else { + // calculate current row distance from previous row without collator + for (i = 0; i < str1Len; ++i) { + nextCol = i + 1; + + for (j = 0; j < str2Len; ++j) { + curCol = nextCol; + + // substution + strCmp = str1.charCodeAt(i) === str2Char[j]; + + nextCol = prevRow[j] + (strCmp ? 0 : 1); + + // insertion + tmp = curCol + 1; + if (nextCol > tmp) { + nextCol = tmp; + } + // deletion + tmp = prevRow[j + 1] + 1; + if (nextCol > tmp) { + nextCol = tmp; + } + + // copy current col value into previous (in preparation for next iteration) + prevRow[j] = curCol; + } + + // copy last col value into previous (in preparation for next iteration) + prevRow[j] = nextCol; + } + } + return nextCol; + } + + }; + + // amd + if (typeof define !== "undefined" && define !== null && define.amd) { + define(function() { + return Levenshtein; + }); + } + // commonjs + else if (typeof module !== "undefined" && module !== null && typeof exports !== "undefined" && module.exports === exports) { + module.exports = Levenshtein; + } + // web worker + else if (typeof self !== "undefined" && typeof self.postMessage === 'function' && typeof self.importScripts === 'function') { + self.Levenshtein = Levenshtein; + } + // browser main thread + else if (typeof window !== "undefined" && window !== null) { + window.Levenshtein = Levenshtein; + } +}()); + |