add hw2

node_modules/lodash/_baseMergeDeep.js

@@ -0,0 +1,94 @@
+var assignMergeValue = require('./_assignMergeValue'),
+    cloneBuffer = require('./_cloneBuffer'),
+    cloneTypedArray = require('./_cloneTypedArray'),
+    copyArray = require('./_copyArray'),
+    initCloneObject = require('./_initCloneObject'),
+    isArguments = require('./isArguments'),
+    isArray = require('./isArray'),
+    isArrayLikeObject = require('./isArrayLikeObject'),
+    isBuffer = require('./isBuffer'),
+    isFunction = require('./isFunction'),
+    isObject = require('./isObject'),
+    isPlainObject = require('./isPlainObject'),
+    isTypedArray = require('./isTypedArray'),
+    safeGet = require('./_safeGet'),
+    toPlainObject = require('./toPlainObject');
+
+/**
+ * A specialized version of `baseMerge` for arrays and objects which performs
+ * deep merges and tracks traversed objects enabling objects with circular
+ * references to be merged.
+ *
+ * @private
+ * @param {Object} object The destination object.
+ * @param {Object} source The source object.
+ * @param {string} key The key of the value to merge.
+ * @param {number} srcIndex The index of `source`.
+ * @param {Function} mergeFunc The function to merge values.
+ * @param {Function} [customizer] The function to customize assigned values.
+ * @param {Object} [stack] Tracks traversed source values and their merged
+ *  counterparts.
+ */
+function baseMergeDeep(object, source, key, srcIndex, mergeFunc, customizer, stack) {
+  var objValue = safeGet(object, key),
+      srcValue = safeGet(source, key),
+      stacked = stack.get(srcValue);
+
+  if (stacked) {
+    assignMergeValue(object, key, stacked);
+    return;
+  }
+  var newValue = customizer
+    ? customizer(objValue, srcValue, (key + ''), object, source, stack)
+    : undefined;
+
+  var isCommon = newValue === undefined;
+
+  if (isCommon) {
+    var isArr = isArray(srcValue),
+        isBuff = !isArr && isBuffer(srcValue),
+        isTyped = !isArr && !isBuff && isTypedArray(srcValue);
+
+    newValue = srcValue;
+    if (isArr || isBuff || isTyped) {
+      if (isArray(objValue)) {
+        newValue = objValue;
+      }
+      else if (isArrayLikeObject(objValue)) {
+        newValue = copyArray(objValue);
+      }
+      else if (isBuff) {
+        isCommon = false;
+        newValue = cloneBuffer(srcValue, true);
+      }
+      else if (isTyped) {
+        isCommon = false;
+        newValue = cloneTypedArray(srcValue, true);
+      }
+      else {
+        newValue = [];
+      }
+    }
+    else if (isPlainObject(srcValue) || isArguments(srcValue)) {
+      newValue = objValue;
+      if (isArguments(objValue)) {
+        newValue = toPlainObject(objValue);
+      }
+      else if (!isObject(objValue) || isFunction(objValue)) {
+        newValue = initCloneObject(srcValue);
+      }
+    }
+    else {
+      isCommon = false;
+    }
+  }
+  if (isCommon) {
+    // Recursively merge objects and arrays (susceptible to call stack limits).
+    stack.set(srcValue, newValue);
+    mergeFunc(newValue, srcValue, srcIndex, customizer, stack);
+    stack['delete'](srcValue);
+  }
+  assignMergeValue(object, key, newValue);
+}
+
+module.exports = baseMergeDeep;