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app_vue/node_modules/commander/lib/suggestSimilar.js

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+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;