damerau-levenshtein - npm Package Compare versions

Comparing version 1.0.0 to 1.0.1

index.js

 // TheSpanishInquisition
 
-// Cache the matrix. Note this implementation is limited to
-// strings of 64 char or less. This could be altered to update
-// dynamically, or a larger value could be used.
+// Cache the matrix. Note that if you not pass a limit this implementation will use a dynamically calculate one.
 
-// TODO: grok it.
-// The matrix was cached, as above comment states, but it was throwing unpredictable results sometimes. Either there was a bug or I was using it wrong. Now matrix is recreated on each call and results are correct. This probabily hits performance.
+module.exports = function(__this, that, limit) {
 
-module.exports = function(__this, that, limit) {
-  var matrix = [];
-  for (var i = 0; i < 64; i++) {
+  var thisLength = __this.length,
+      thatLength = that.length,
+      matrix = [];
+
+  // If the limit is not defined it will be calculate from this and that args.
+  limit = (limit || ((thatLength > thisLength ? thatLength : thisLength)))+1;
+
+  for (var i = 0; i < limit; i++) {
     matrix[i] = [i];
-    matrix[i].length = 64;
+    matrix[i].length = limit;
   }
-  for (var i = 0; i < 64; i++) {
+  for (i = 0; i < limit; i++) {
     matrix[0][i] = i;
   }
 
-  var thisLength = __this.length,
-      thatLength = that.length;
-
-  prepare = function (steps) {
-    distance            = {};
-    distance.steps      = steps;
-    distance.relative   = steps / Math.max(thisLength, thatLength);
-    distance.similarity = 1 - distance.relative;
-
-    return distance;
+  if (Math.abs(thisLength - thatLength) > (limit || 100)){
+    return prepare (limit || 100);
   }
+  if (thisLength === 0){
+    return prepare (thatLength);
+  }
+  if (thatLength === 0){
+    return prepare (thisLength);
+  }
 
-  if (Math.abs(thisLength - thatLength) > (limit || 32)) return prepare (limit || 32);
-  if (thisLength === 0) return prepare (thatLength);
-  if (thatLength === 0) return prepare (thisLength);
-
   // Calculate matrix.
@@ -49,3 +45,3 @@ var this_i, that_j, cost, min, t;
       // Calculate the minimum (much faster than Math.min(...)).
-      min    = matrix[i - 1][j    ] + 1;                                              // Deletion.
+      min    = matrix[i - 1][j    ] + 1; // Deletion.
       if ((t = matrix[i    ][j - 1] + 1   ) < min) min = t;   // Insertion.
@@ -55,8 +51,20 @@ if ((t = matrix[i - 1][j - 1] + cost) < min) min = t;   // Substitution.
       // Update matrix.
-      matrix[i][j] = (i > 1 && j > 1 && this_i === that[j-2] && this[i-2] === that_j && (t = matrix[i-2][j-2]+cost) < min) ? t : min; // Transposition.
+      matrix[i][j] = (i > 1 && j > 1 && this_i === that[j-2] && __this[i-2] === that_j && (t = matrix[i-2][j-2]+cost) < min) ? t : min; // Transposition.
     }
   }
 
-  return prepare (matrix[thisLength][thatLength])
+  return prepare (matrix[thisLength][thatLength]);
 
-};
+/**
+ *
+ */
+  function prepare(steps) {
+    var distance = {
+      steps: steps,
+      relative: (steps / Math.max(thisLength, thatLength)) || 0
+    };
+    distance.similarity = (distance.relative !== 0) ?(1 - distance.relative) : 0;
+    return distance;
+  }
+
+};

package.json

 {
   "name": "damerau-levenshtein",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Damerau - Levenshtein distance by The Spanish Inquisition + relative distance",
@@ -18,3 +18,6 @@ "main": "index.js",
   "author": "The Spanish Inquisition",
-  "license": "BSD-2-Clause"
+  "license": "BSD-2-Clause",
+  "devDependencies": {
+    "mocha": "^3.0.2"
+  }
 }

No alert changes

Improved metrics

Total package byte prevSize

6809

increased by130.74%

Number of package files

6

increased by100%

Lines of code

125

increased by171.74%

Worsened metrics

Dev dependency count

1

increased byInfinity%

No dependency changes