flying-hero
96f6318101
新增: - backend/venv/ - Python 虚拟环境 - backend/start.sh - 启动脚本（使用虚拟环境） - backend/requirements.txt - 依赖列表 - .gitignore - 忽略虚拟环境和缓存文件 说明: - 每个项目使用独立虚拟环境 - 避免依赖冲突 - 启动脚本自动创建和激活虚拟环境
101 lines
2.7 KiB
JavaScript
101 lines
2.7 KiB
JavaScript
const maxDistance = 3;
|
||
|
||
function editDistance(a, b) {
|
||
// https://en.wikipedia.org/wiki/Damerau–Levenshtein_distance
|
||
// Calculating optimal string alignment distance, no substring is edited more than once.
|
||
// (Simple implementation.)
|
||
|
||
// Quick early exit, return worst case.
|
||
if (Math.abs(a.length - b.length) > maxDistance) return Math.max(a.length, b.length);
|
||
|
||
// distance between prefix substrings of a and b
|
||
const d = [];
|
||
|
||
// pure deletions turn a into empty string
|
||
for (let i = 0; i <= a.length; i++) {
|
||
d[i] = [i];
|
||
}
|
||
// pure insertions turn empty string into b
|
||
for (let j = 0; j <= b.length; j++) {
|
||
d[0][j] = j;
|
||
}
|
||
|
||
// fill matrix
|
||
for (let j = 1; j <= b.length; j++) {
|
||
for (let i = 1; i <= a.length; i++) {
|
||
let cost = 1;
|
||
if (a[i - 1] === b[j - 1]) {
|
||
cost = 0;
|
||
} else {
|
||
cost = 1;
|
||
}
|
||
d[i][j] = Math.min(
|
||
d[i - 1][j] + 1, // deletion
|
||
d[i][j - 1] + 1, // insertion
|
||
d[i - 1][j - 1] + cost // substitution
|
||
);
|
||
// transposition
|
||
if (i > 1 && j > 1 && a[i - 1] === b[j - 2] && a[i - 2] === b[j - 1]) {
|
||
d[i][j] = Math.min(d[i][j], d[i - 2][j - 2] + 1);
|
||
}
|
||
}
|
||
}
|
||
|
||
return d[a.length][b.length];
|
||
}
|
||
|
||
/**
|
||
* Find close matches, restricted to same number of edits.
|
||
*
|
||
* @param {string} word
|
||
* @param {string[]} candidates
|
||
* @returns {string}
|
||
*/
|
||
|
||
function suggestSimilar(word, candidates) {
|
||
if (!candidates || candidates.length === 0) return '';
|
||
// remove possible duplicates
|
||
candidates = Array.from(new Set(candidates));
|
||
|
||
const searchingOptions = word.startsWith('--');
|
||
if (searchingOptions) {
|
||
word = word.slice(2);
|
||
candidates = candidates.map(candidate => candidate.slice(2));
|
||
}
|
||
|
||
let similar = [];
|
||
let bestDistance = maxDistance;
|
||
const minSimilarity = 0.4;
|
||
candidates.forEach((candidate) => {
|
||
if (candidate.length <= 1) return; // no one character guesses
|
||
|
||
const distance = editDistance(word, candidate);
|
||
const length = Math.max(word.length, candidate.length);
|
||
const similarity = (length - distance) / length;
|
||
if (similarity > minSimilarity) {
|
||
if (distance < bestDistance) {
|
||
// better edit distance, throw away previous worse matches
|
||
bestDistance = distance;
|
||
similar = [candidate];
|
||
} else if (distance === bestDistance) {
|
||
similar.push(candidate);
|
||
}
|
||
}
|
||
});
|
||
|
||
similar.sort((a, b) => a.localeCompare(b));
|
||
if (searchingOptions) {
|
||
similar = similar.map(candidate => `--${candidate}`);
|
||
}
|
||
|
||
if (similar.length > 1) {
|
||
return `\n(Did you mean one of ${similar.join(', ')}?)`;
|
||
}
|
||
if (similar.length === 1) {
|
||
return `\n(Did you mean ${similar[0]}?)`;
|
||
}
|
||
return '';
|
||
}
|
||
|
||
exports.suggestSimilar = suggestSimilar;
|