feat: Add concatenating SemiGroup for String and Enforce tests for Th…

…ese (#252)
MikuroXina · Aug 5, 2024 · 9d7e227 · 9d7e227
1 parent c31e8ef
commit 9d7e227
Show file tree

Hide file tree

Showing 3 changed files with 543 additions and 2 deletions.
diff --git a/src/string.ts b/src/string.ts
@@ -1,5 +1,6 @@
 import { equal, greater, less, type Ordering } from "./ordering.ts";
 import { fromCmp, type Ord } from "./type-class/ord.ts";
+import { type SemiGroup, semiGroupSymbol } from "./type-class/semi-group.ts";
 
 export const cmp = (lhs: string, rhs: string): Ordering => {
     if (lhs === rhs) {
@@ -11,3 +12,11 @@ export const cmp = (lhs: string, rhs: string): Ordering => {
     return greater;
 };
 export const ord: Ord<string> = fromCmp(() => cmp)();
+
+/**
+ * A `SemiGroup` instance of concatenating `string`s.
+ */
+export const semiGroup: SemiGroup<string> = {
+    combine: (l, r) => l + r,
+    [semiGroupSymbol]: true,
+};