Add (untested) tree-map-flat utility

src/packages/tree-map-flat/index.js

@@ -0,0 +1,35 @@
+"use strict";
+
+const isIterable = require("is-iterable");
+const forEach = require("../for-each");
+
+module.exports = function treeMap(tree, mapper, options = {}) {
+	let key = options.key ?? "children";
+	let recurseAfterMap = options.recurseAfterMap ?? false;
+
+	let results = [];
+
+	function step(subtree) {
+		let mapped = mapper(subtree);
+
+		results.push(mapped);
+
+		let nextChildren = (recurseAfterMap)
+			? mapped[key]
+			: subtree[key];
+
+		if (isIterable(nextChildren)) {
+			forEach(nextChildren, step);
+		} else if (nextChildren != null && typeof nextChildren === "object") {
+			step(nextChildren);
+		}
+	}
+
+	if (isIterable(tree)) {
+		forEach(tree, step);
+	} else {
+		step(tree);
+	}
+
+	return results;
+};