add some packages

node_modules/babel-plugin-minify-mangle-names/lib/charset.js

@@ -0,0 +1,52 @@
+"use strict";
+
+const CHARSET = ("abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ$_").split("");
+module.exports = class Charset {
+  constructor(shouldConsider) {
+    this.shouldConsider = shouldConsider;
+    this.chars = CHARSET.slice();
+    this.frequency = {};
+    this.chars.forEach(c => {
+      this.frequency[c] = 0;
+    });
+    this.finalized = false;
+  }
+
+  consider(str) {
+    if (!this.shouldConsider) {
+      return;
+    }
+
+    str.split("").forEach(c => {
+      if (this.frequency[c] != null) {
+        this.frequency[c]++;
+      }
+    });
+  }
+
+  sort() {
+    if (this.shouldConsider) {
+      this.chars = this.chars.sort((a, b) => this.frequency[b] - this.frequency[a]);
+    }
+
+    this.finalized = true;
+  }
+
+  getIdentifier(num) {
+    if (!this.finalized) {
+      throw new Error("Should sort first");
+    }
+
+    let ret = "";
+    num++;
+
+    do {
+      num--;
+      ret += this.chars[num % this.chars.length];
+      num = Math.floor(num / this.chars.length);
+    } while (num > 0);
+
+    return ret;
+  }
+
+};