🚴 perf: Inline loopy code inside core/concatenate/nodes.

functional-data-structure · Oct 15, 2021 · 35c0268 · 35c0268
1 parent 032d293
commit 35c0268
Showing 1 changed file with 51 additions and 23 deletions.
diff --git a/src/0-core/concatenate/nodes.js b/src/0-core/concatenate/nodes.js
@@ -4,29 +4,57 @@ import {node2, node3} from '../../2-node/index.js';
 
 export function nodes(M, list) {
 	assert(list.length >= 3 && list.length <= 12);
-	const out = [];
-
-	const n = list.length;
-
-	let i = 0;
-
-	switch (n % 3) {
-		case 1:
-			out.push(node2(M, list[0], list[1]));
-			out.push(node2(M, list[2], list[3]));
-			i += 4;
-			break;
-		case 2:
-			out.push(node2(M, list[0], list[1]));
-			i += 2;
-			break;
+	switch (list.length) {
+		case 3:
+			return [node3(M, list[0], list[1], list[2])];
+		case 4:
+			return [node2(M, list[0], list[1]), node2(M, list[2], list[3])];
+		case 5:
+			return [node3(M, list[0], list[1], list[2]), node2(M, list[3], list[4])];
+		case 6:
+			return [
+				node3(M, list[0], list[1], list[2]),
+				node3(M, list[3], list[4], list[5]),
+			];
+		case 7:
+			return [
+				node2(M, list[0], list[1]),
+				node3(M, list[2], list[3], list[4]),
+				node2(M, list[5], list[6]),
+			];
+		case 8:
+			return [
+				node3(M, list[0], list[1], list[2]),
+				node2(M, list[3], list[4]),
+				node3(M, list[5], list[6], list[7]),
+			];
+		case 9:
+			return [
+				node3(M, list[0], list[1], list[2]),
+				node3(M, list[3], list[4], list[5]),
+				node3(M, list[6], list[7], list[8]),
+			];
+		case 10:
+			return [
+				node2(M, list[0], list[1]),
+				node3(M, list[2], list[3], list[4]),
+				node3(M, list[5], list[6], list[7]),
+				node2(M, list[8], list[9]),
+			];
+		case 11:
+			return [
+				node2(M, list[0], list[1]),
+				node3(M, list[2], list[3], list[4]),
+				node3(M, list[5], list[6], list[7]),
+				node3(M, list[8], list[9], list[10]),
+			];
 		default:
-			break;
+			assert(list.length === 12);
+			return [
+				node3(M, list[0], list[1], list[2]),
+				node3(M, list[3], list[4], list[5]),
+				node3(M, list[6], list[7], list[8]),
+				node3(M, list[9], list[10], list[11]),
+			];
 	}
-
-	for (; i < n; i += 3) {
-		out.push(node3(M, list[i], list[i + 1], list[i + 2]));
-	}
-
-	return out;
 }