remove Array.from() polyfill and recode references to it

Signed-off-by: andrew-coleman <andrew_coleman@uk.ibm.com>

Author: andrew-coleman

polyfill.js

@@ -13,86 +13,6 @@ Number.isInteger = Number.isInteger || function(value) {
         Math.floor(value) === value;
 };
 
-// Production steps of ECMA-262, Edition 6, 22.1.2.1
-if (!Array.from) {
-    Array.from = (function () {
-        'use strict';
-        var toStr = Object.prototype.toString;
-        var isCallable = function (fn) {
-            return typeof fn === 'function' || toStr.call(fn) === '[object Function]';
-        };
-        var toInteger = function (value) {
-            var number = Number(value);
-            if (isNaN(number)) { return 0; }
-            if (number === 0 || !isFinite(number)) { return number; }
-            return (number > 0 ? 1 : -1) * Math.floor(Math.abs(number));
-        };
-
-        var toLength = function (value) {
-            var len = toInteger(value);
-            return len >>> 0;
-        };
-
-        // The length property of the from method is 1.
-        return function from(arrayLike/*, mapFn, thisArg */) {
-            // 1. Let C be the this value.
-            var C = this;
-
-            // 2. Let items be ToObject(arrayLike).
-            var items = Object(arrayLike);
-
-            // 3. ReturnIfAbrupt(items).
-            if (arrayLike === null) {
-                throw new TypeError('Array.from requires an array-like object - not null or undefined');
-            }
-
-            // 4. If mapfn is undefined, then let mapping be false.
-            var mapFn = arguments.length > 1 ? arguments[1] : void undefined;
-            var T;
-            if (typeof mapFn !== 'undefined') {
-                // 5. else
-                // 5. a If IsCallable(mapfn) is false, throw a TypeError exception.
-                if (!isCallable(mapFn)) {
-                    throw new TypeError('Array.from: when provided, the second argument must be a function');
-                }
-
-                // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined.
-                if (arguments.length > 2) {
-                    T = arguments[2];
-                }
-            }
-
-            // 10. Let lenValue be Get(items, "length").
-            // 11. Let len be ToLength(lenValue).
-            var len = toLength(items.length);
-
-            // 13. If IsConstructor(C) is true, then
-            // 13. a. Let A be the result of calling the [[Construct]] internal method
-            // of C with an argument list containing the single item len.
-            // 14. a. Else, Let A be ArrayCreate(len).
-            var A = isCallable(C) ? Object(new C(len)) : new Array(len);
-
-            // 16. Let k be 0.
-            var k = 0;
-            // 17. Repeat, while k < len… (also steps a - h)
-            var kValue;
-            while (k < len) {
-                kValue = items[k];
-                if (mapFn) {
-                    A[k] = typeof T === 'undefined' ? mapFn(kValue, k) : mapFn.call(T, kValue, k);
-                } else {
-                    A[k] = kValue;
-                }
-                k += 1;
-            }
-            // 18. Let putStatus be Put(A, "length", len, true).
-            A.length = len;
-            // 20. Return A.
-            return A;
-        };
-    }());
-}
-
 if (!String.fromCodePoint) (function(stringFromCharCode) {
     var fromCodePoint = function(_) {
         var codeUnits = [], codeLen = 0, result = "";

src/datetime.js

@@ -4,6 +4,8 @@
  *   This project is licensed under the MIT License, see LICENSE
  */
 
+const utils = require('./utils');
+
 /**
  * DateTime formatting and parsing functions
  * Implements the xpath-functions format-date-time specification
@@ -12,6 +14,8 @@
 const dateTime = (function () {
     'use strict';
 
+    const stringToArray = utils.stringToArray;
+
     const few = ['Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten',
         'Eleven', 'Twelve', 'Thirteen', 'Fourteen', 'Fifteen', 'Sixteen', 'Seventeen', 'Eighteen', 'Nineteen'];
     const ordinals = ['Zeroth', 'First', 'Second', 'Third', 'Fourth', 'Fifth', 'Sixth', 'Seventh', 'Eighth', 'Ninth', 'Tenth',
@@ -270,7 +274,7 @@ const dateTime = (function () {
                     formattedInteger = padding + formattedInteger;
                 }
                 if (format.zeroCode !== 0x30) {
-                    formattedInteger = Array.from(formattedInteger).map(code => {
+                    formattedInteger = stringToArray(formattedInteger).map(code => {
                         return String.fromCodePoint(code.codePointAt(0) + format.zeroCode - 0x30);
                     }).join('');
                 }
@@ -371,7 +375,7 @@ const dateTime = (function () {
                 let optionalDigits = 0;
                 let groupingSeparators = [];
                 let separatorPosition = 0;
-                const formatCodepoints = Array.from(primaryFormat, c => c.codePointAt(0)).reverse(); // reverse the array to determine positions of grouping-separator-signs
+                const formatCodepoints = stringToArray(primaryFormat).map(c => c.codePointAt(0)).reverse(); // reverse the array to determine positions of grouping-separator-signs
                 formatCodepoints.forEach((codePoint) => {
                     // step though each char in the picture to determine the digit group
                     let digit = false;
@@ -813,7 +817,7 @@ const dateTime = (function () {
         return componentValue;
     };
 
-    const iso8601Spec = analyseDateTimePicture('[Y0001]-[M01]-[D01]T[H01]:[m01]:[s01].[f001][Z01:01t]');
+    let iso8601Spec = null;
 
     /**
      * formats the date/time as specified by the XPath fn:format-dateTime function
@@ -907,6 +911,9 @@ const dateTime = (function () {
         let formatSpec;
         if(typeof picture === 'undefined') {
             // default to ISO 8601 format
+            if (iso8601Spec === null) {
+                iso8601Spec = analyseDateTimePicture('[Y0001]-[M01]-[D01]T[H01]:[m01]:[s01].[f001][Z01:01t]');
+            }
             formatSpec = iso8601Spec;
         } else {
             formatSpec = analyseDateTimePicture(picture);

src/functions.js

@@ -19,6 +19,7 @@ const functions = (() => {
     var isIterable = utils.isIterable;
     var getFunctionArity = utils.getFunctionArity;
     var deepEquals = utils.isDeepEqual;
+    var stringToArray = utils.stringToArray;
 
     /**
      * Sum function
@@ -150,7 +151,7 @@ const functions = (() => {
             return undefined;
         }
 
-        var strArray = Array.from(str);
+        var strArray = stringToArray(str);
         var strLength = strArray.length;
 
         if (strLength + start < 0) {
@@ -247,7 +248,7 @@ const functions = (() => {
             return undefined;
         }
 
-        return Array.from(str).length;
+        return stringToArray(str).length;
     }
 
     /**

src/utils.js

@@ -176,6 +176,19 @@ const utils = (() => {
         return false;
     }
 
+    /**
+     * converts a string to an array of characters
+     * @param {string} str - the input string
+     * @returns {Array} - the array of characters
+     */
+    function stringToArray(str) {
+        var arr = [];
+        for (let char of str) {
+            arr.push(char);
+        }
+        return arr;
+    }
+
     return {
         isNumeric,
         isArrayOfStrings,
@@ -186,7 +199,8 @@ const utils = (() => {
         isLambda,
         isIterable,
         getFunctionArity,
-        isDeepEqual
+        isDeepEqual,
+        stringToArray
     };
 })();