Move internal modules to “internal” folder.

.internal/composeArgs.js

@@ -0,0 +1,41 @@
+/* Built-in method references for those with the same name as other `lodash` methods. */
+const nativeMax = Math.max;
+
+/**
+ * Creates an array that is the composition of partially applied arguments,
+ * placeholders, and provided arguments into a single array of arguments.
+ *
+ * @private
+ * @param {Array} args The provided arguments.
+ * @param {Array} partials The arguments to prepend to those provided.
+ * @param {Array} holders The `partials` placeholder indexes.
+ * @params {boolean} [isCurried] Specify composing for a curried function.
+ * @returns {Array} Returns the new array of composed arguments.
+ */
+function composeArgs(args, partials, holders, isCurried) {
+  const argsLength = args.length;
+  const holdersLength = holders.length;
+  const leftLength = partials.length;
+
+  let argsIndex = -1;
+  let leftIndex = -1;
+  let rangeLength = nativeMax(argsLength - holdersLength, 0);
+
+  const result = Array(leftLength + rangeLength);
+  const isUncurried = !isCurried;
+
+  while (++leftIndex < leftLength) {
+    result[leftIndex] = partials[leftIndex];
+  }
+  while (++argsIndex < holdersLength) {
+    if (isUncurried || argsIndex < argsLength) {
+      result[holders[argsIndex]] = args[argsIndex];
+    }
+  }
+  while (rangeLength--) {
+    result[leftIndex++] = args[argsIndex++];
+  }
+  return result;
+}
+
+export default composeArgs;