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- "use strict";
- // @see: https://github.com/microsoft/TypeScript/blob/master/src/compiler/checker.ts
- Object.defineProperty(exports, "__esModule", { value: true });
- exports.getSpellingSuggestion = void 0;
- /**
- * Given a name and a list of names that are not equal to the name, return a
- * spelling suggestion if there is one that is close enough. Names less than
- * length 3 only check for case-insensitive equality, not Levenshtein distance.
- *
- * - If there is a candidate that's the same except for case, return that.
- * - If there is a candidate that's within one edit of the name, return that.
- * - Otherwise, return the candidate with the smallest Levenshtein distance,
- * except for candidates:
- * * With no name
- * * Whose length differs from the target name by more than 0.34 of the
- * length of the name.
- * * Whose levenshtein distance is more than 0.4 of the length of the
- * name (0.4 allows 1 substitution/transposition for every 5 characters,
- * and 1 insertion/deletion at 3 characters)
- */
- function getSpellingSuggestion(name, candidates, getName) {
- const maximumLengthDifference = Math.min(2, Math.floor(name.length * 0.34));
- // If the best result isn't better than this, don't bother.
- let bestDistance = Math.floor(name.length * 0.4) + 1;
- let bestCandidate;
- let justCheckExactMatches = false;
- const nameLowerCase = name.toLowerCase();
- // eslint-disable-next-line
- for (const candidate of candidates) {
- const candidateName = getName(candidate);
- if (candidateName !== undefined &&
- Math.abs(candidateName.length - nameLowerCase.length) <=
- maximumLengthDifference) {
- const candidateNameLowerCase = candidateName.toLowerCase();
- if (candidateNameLowerCase === nameLowerCase) {
- if (candidateName === name) {
- continue;
- }
- return candidate;
- }
- if (justCheckExactMatches) {
- continue;
- }
- if (candidateName.length < 3) {
- // Don't bother, user would have noticed a
- // 2-character name having an extra character.
- continue;
- }
- // Only care about a result better than the best so far.
- const distance = levenshteinWithMax(nameLowerCase, candidateNameLowerCase, bestDistance - 1);
- if (distance === undefined) {
- continue;
- }
- if (distance < 3) {
- justCheckExactMatches = true;
- bestCandidate = candidate;
- }
- else {
- // Debug.assert(distance < bestDistance)
- bestDistance = distance;
- bestCandidate = candidate;
- }
- }
- }
- return bestCandidate;
- }
- exports.getSpellingSuggestion = getSpellingSuggestion;
- function levenshteinWithMax(s1, s2, max) {
- let previous = new Array(s2.length + 1); // eslint-disable-line
- let current = new Array(s2.length + 1); // eslint-disable-line
- /** Represents any value > max. We don't care about the particular value. */
- const big = max + 1;
- for (let i = 0; i <= s2.length; i += 1) {
- previous[i] = i;
- }
- for (let i = 1; i <= s1.length; i += 1) {
- const c1 = s1.charCodeAt(i - 1);
- const minJ = i > max ? i - max : 1;
- const maxJ = s2.length > max + i ? max + i : s2.length;
- current[0] = i;
- /** Smallest value of the matrix in the ith column. */
- let colMin = i;
- for (let j = 1; j < minJ; j += 1) {
- current[j] = big;
- }
- for (let j = minJ; j <= maxJ; j += 1) {
- const dist = c1 === s2.charCodeAt(j - 1)
- ? previous[j - 1]
- : Math.min(
- /* delete */ previous[j] + 1,
- /* insert */ current[j - 1] + 1,
- /* substitute */ previous[j - 1] + 2);
- current[j] = dist;
- colMin = Math.min(colMin, dist);
- }
- for (let j = maxJ + 1; j <= s2.length; j += 1) {
- current[j] = big;
- }
- if (colMin > max) {
- // Give up -- everything in this column is > max
- // and it can't get better in future columns.
- return undefined;
- }
- const temp = previous;
- previous = current;
- current = temp;
- }
- const res = previous[s2.length];
- return res > max ? undefined : res;
- }
- //# sourceMappingURL=suggestion.js.map
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