feat: init

node_modules/regexp-tree/dist/optimizer/transforms/disjunction-remove-duplicates-transform.js

@@ -0,0 +1,44 @@
+/**
+ * The MIT License (MIT)
+ * Copyright (c) 2017-present Dmitry Soshnikov <dmitry.soshnikov@gmail.com>
+ */
+
+'use strict';
+
+var NodePath = require('../../traverse/node-path');
+
+var _require = require('../../transform/utils'),
+    disjunctionToList = _require.disjunctionToList,
+    listToDisjunction = _require.listToDisjunction;
+
+/**
+ * Removes duplicates from a disjunction sequence:
+ *
+ * /(ab|bc|ab)+(xy|xy)+/ -> /(ab|bc)+(xy)+/
+ */
+
+
+module.exports = {
+  Disjunction: function Disjunction(path) {
+    var node = path.node;
+
+    // Make unique nodes.
+
+    var uniqueNodesMap = {};
+
+    var parts = disjunctionToList(node).filter(function (part) {
+      var encoded = part ? NodePath.getForNode(part).jsonEncode() : 'null';
+
+      // Already recorded this part, filter out.
+      if (uniqueNodesMap.hasOwnProperty(encoded)) {
+        return false;
+      }
+
+      uniqueNodesMap[encoded] = part;
+      return true;
+    });
+
+    // Replace with the optimized disjunction.
+    path.replace(listToDisjunction(parts));
+  }
+};