@antv/x6
Version:
JavaScript diagramming library that uses SVG and HTML for rendering
110 lines • 4.53 kB
JavaScript
;
// @see: https://github.com/microsoft/TypeScript/blob/master/src/compiler/checker.ts
Object.defineProperty(exports, "__esModule", { value: true });
exports.getSpellingSuggestion = getSpellingSuggestion;
/**
* 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;
}
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;
}
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