more work

node_modules/lodash/internal/baseFlatten.js

@@ -0,0 +1,44 @@
+var isArguments = require('../lang/isArguments'),
+    isArray = require('../lang/isArray'),
+    isLength = require('./isLength'),
+    isObjectLike = require('./isObjectLike');
+
+/**
+ * The base implementation of `_.flatten` with added support for restricting
+ * flattening and specifying the start index.
+ *
+ * @private
+ * @param {Array} array The array to flatten.
+ * @param {boolean} isDeep Specify a deep flatten.
+ * @param {boolean} isStrict Restrict flattening to arrays and `arguments` objects.
+ * @returns {Array} Returns the new flattened array.
+ */
+function baseFlatten(array, isDeep, isStrict) {
+  var index = -1,
+      length = array.length,
+      resIndex = -1,
+      result = [];
+
+  while (++index < length) {
+    var value = array[index];
+
+    if (isObjectLike(value) && isLength(value.length) && (isArray(value) || isArguments(value))) {
+      if (isDeep) {
+        // Recursively flatten arrays (susceptible to call stack limits).
+        value = baseFlatten(value, isDeep, isStrict);
+      }
+      var valIndex = -1,
+          valLength = value.length;
+
+      result.length += valLength;
+      while (++valIndex < valLength) {
+        result[++resIndex] = value[valIndex];
+      }
+    } else if (!isStrict) {
+      result[++resIndex] = value;
+    }
+  }
+  return result;
+}
+
+module.exports = baseFlatten;