Refactor reduceRight and modify a _.difference benchmark.

Former-commit-id: b70272ac5316fe1bee52b9611a1a5ea4d761dd3c

build.js

@@ -133,7 +133,7 @@
     'random': [],
     'range': [],
     'reduce': [],
-    'reduceRight': ['keys', 'reduce'],
+    'reduceRight': ['forEach', 'keys'],
     'reject': ['identity'],
     'rest': [],
     'result': ['isFunction'],
@@ -1146,7 +1146,7 @@
       source = source.replace(/noArraySliceOnStrings *\?[^:]+: *([^)]+)/g, '$1');
 
       // remove `noCharByIndex` from `_.reduceRight`
-      source = source.replace(/noCharByIndex *&&[^:]+: *([^;]+)/g, '$1');
+      source = source.replace(/}\s*else if *\(noCharByIndex[^}]+/, '');
 
       source = removeVar(source, 'extendIteratorOptions');
       source = removeVar(source, 'iteratorTemplate');

lodash.js

@@ -2220,19 +2220,23 @@
     if (!collection) {
       return accumulator;
     }
-    var length = collection.length,
+    var iteratee = collection,
+        length = collection.length,
         noaccum = arguments.length < 3;
 
     if (length !== +length) {
       var props = keys(collection);
       length = props.length;
+    } else if (noCharByIndex && toString.call(collection) == stringClass) {
+      iteratee = collection.split('');
     }
-    return reduce(collection, function(accumulator, value, index, object) {
-      var index = props ? props[--length] : --length;
-      return noaccum
-        ? (noaccum = false, object[index])
-        : callback.call(thisArg, accumulator, object[index], index, object);
-    }, accumulator);
+    forEach(collection, function(value, index, object) {
+      index = props ? props[--length] : --length;
+      accumulator = noaccum
+        ? (noaccum = false, iteratee[index])
+        : callback.call(thisArg, accumulator, iteratee[index], index, object);
+    });
+    return accumulator;
   }
 
   /**

perf/perf.js

@@ -276,7 +276,6 @@
         var twentyFiveValues = Array(25),\
             twentyFiveValues2 = Array(25),\
             fiftyValues = Array(50),\
-            fiftyValues2 = Array(50),\
             seventyFiveValues = Array(75),\
             seventyFiveValues2 = Array(75),\
             lowerChars = "abcdefghijklmnopqrstuvwxyz".split(""),\
@@ -294,14 +293,11 @@
             }\
             fiftyValues[index] =\
             seventyFiveValues[index] = lowerChars[index];\
-            \
-            fiftyValues2[index] =\
             seventyFiveValues2[index] = upperChars[index];\
           }\
           else {\
             if (index < 50) {\
               fiftyValues[index] = index;\
-              fiftyValues2[index] = index + (index < 40 ? 75 : 0);\
             }\
             seventyFiveValues[index] = index;\
             seventyFiveValues2[index] = index + (index < 60 ? 75 : 0);\
@@ -575,13 +571,13 @@
   );
 
   suites.push(
-    Benchmark.Suite('`_.difference` iterating 50 elements')
+    Benchmark.Suite('`_.difference` iterating 50 and 75 elements')
       .add('Lo-Dash', {
-        'fn': 'lodash.difference(fiftyValues, fiftyValues2)',
+        'fn': 'lodash.difference(fiftyValues, seventyFiveValues2)',
         'teardown': 'function multiArrays(){}'
       })
       .add('Underscore', {
-        'fn': '_.difference(fiftyValues, fiftyValues2)',
+        'fn': '_.difference(fiftyValues, seventyFiveValues2)',
         'teardown': 'function multiArrays(){}'
       })
   );