更新

TongjiUniApp/node_modules/any-base/src/converter.js

@@ -0,0 +1,80 @@
+'use strict';
+
+/**
+ * Converter
+ *
+ * @param {string|Array} srcAlphabet
+ * @param {string|Array} dstAlphabet
+ * @constructor
+ */
+function Converter(srcAlphabet, dstAlphabet) {
+    if (!srcAlphabet || !dstAlphabet || !srcAlphabet.length || !dstAlphabet.length) {
+        throw new Error('Bad alphabet');
+    }
+    this.srcAlphabet = srcAlphabet;
+    this.dstAlphabet = dstAlphabet;
+}
+
+/**
+ * Convert number from source alphabet to destination alphabet
+ *
+ * @param {string|Array} number - number represented as a string or array of points
+ *
+ * @returns {string|Array}
+ */
+Converter.prototype.convert = function(number) {
+    var i, divide, newlen,
+    numberMap = {},
+    fromBase = this.srcAlphabet.length,
+    toBase = this.dstAlphabet.length,
+    length = number.length,
+    result = typeof number === 'string' ? '' : [];
+
+    if (!this.isValid(number)) {
+        throw new Error('Number "' + number + '" contains of non-alphabetic digits (' + this.srcAlphabet + ')');
+    }
+
+    if (this.srcAlphabet === this.dstAlphabet) {
+        return number;
+    }
+
+    for (i = 0; i < length; i++) {
+        numberMap[i] = this.srcAlphabet.indexOf(number[i]);
+    }
+    do {
+        divide = 0;
+        newlen = 0;
+        for (i = 0; i < length; i++) {
+            divide = divide * fromBase + numberMap[i];
+            if (divide >= toBase) {
+                numberMap[newlen++] = parseInt(divide / toBase, 10);
+                divide = divide % toBase;
+            } else if (newlen > 0) {
+                numberMap[newlen++] = 0;
+            }
+        }
+        length = newlen;
+        result = this.dstAlphabet.slice(divide, divide + 1).concat(result);
+    } while (newlen !== 0);
+
+    return result;
+};
+
+/**
+ * Valid number with source alphabet
+ *
+ * @param {number} number
+ *
+ * @returns {boolean}
+ */
+Converter.prototype.isValid = function(number) {
+    var i = 0;
+    for (; i < number.length; ++i) {
+        if (this.srcAlphabet.indexOf(number[i]) === -1) {
+            return false;
+        }
+    }
+    return true;
+};
+
+module.exports = Converter;