Move internal modules to “internal” folder.

.internal/basePullAll.js

@@ -0,0 +1,47 @@
+import arrayMap from './.internal/arrayMap.js';
+import baseIndexOf from './.internal/baseIndexOf.js';
+import baseIndexOfWith from './.internal/baseIndexOfWith.js';
+import copyArray from './.internal/copyArray.js';
+
+/** Built-in value references. */
+const splice = Array.prototype.splice;
+
+/**
+ * The base implementation of `pullAllBy`.
+ *
+ * @private
+ * @param {Array} array The array to modify.
+ * @param {Array} values The values to remove.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns `array`.
+ */
+function basePullAll(array, values, iteratee, comparator) {
+  const indexOf = comparator ? baseIndexOfWith : baseIndexOf;
+  const length = values.length;
+
+  let index = -1;
+  let seen = array;
+
+  if (array === values) {
+    values = copyArray(values);
+  }
+  if (iteratee) {
+    seen = arrayMap(array, value => iteratee(value));
+  }
+  while (++index < length) {
+    let fromIndex = 0;
+    const value = values[index];
+    const computed = iteratee ? iteratee(value) : value;
+
+    while ((fromIndex = indexOf(seen, computed, fromIndex, comparator)) > -1) {
+      if (seen !== array) {
+        splice.call(seen, fromIndex, 1);
+      }
+      splice.call(array, fromIndex, 1);
+    }
+  }
+  return array;
+}
+
+export default basePullAll;