Adds HashMap.hasBy (#4915)

Co-authored-by: Tim <hello@timsmart.co>

Author: vinassefranche

.changeset/fine-groups-change.md

@@ -0,0 +1,14 @@
+---
+"effect": minor
+---
+
+Add HashMap.hasBy helper
+
+```ts
+import { HashMap } from "effect"
+
+const hm = HashMap.make([1, 'a'])
+HashMap.hasBy(hm, (value, key) => value === 'a' && key === 1); // -> true
+HashMap.hasBy(hm, (value) => value === 'b'); // -> false
+
+```

packages/effect/src/HashMap.ts

@@ -194,6 +194,27 @@ export const hasHash: {
   <K1 extends K, K, V>(self: HashMap<K, V>, key: K1, hash: number): boolean
 } = HM.hasHash
 
+/**
+ * Checks if an element matching the given predicate exists in the given `HashMap`.
+ *
+ * @example
+ * ```ts
+ * import { HashMap } from "effect"
+ *
+ * const hm = HashMap.make([1, 'a'])
+ * HashMap.hasBy(hm, (value, key) => value === 'a' && key === 1); // -> true
+ * HashMap.hasBy(hm, (value) => value === 'b'); // -> false
+ *
+ * ```
+ *
+ * @since 3.16.0
+ * @category elements
+ */
+export const hasBy: {
+  <K, V>(predicate: (value: NoInfer<V>, key: NoInfer<K>) => boolean): (self: HashMap<K, V>) => boolean
+  <K, V>(self: HashMap<K, V>, predicate: (value: NoInfer<V>, key: NoInfer<K>) => boolean): boolean
+} = HM.hasBy
+
 /**
  * Sets the specified key to the specified value using the internal hashing
  * function.

packages/effect/src/internal/hashMap.ts

@@ -287,6 +287,12 @@ export const hasHash = Dual.dual<
   <K, V, K1 extends K>(self: HM.HashMap<K, V>, key: K1, hash: number) => boolean
 >(3, (self, key, hash) => Option.isSome(getHash(self, key, hash)))
 
+/** @internal */
+export const hasBy = Dual.dual<
+  <K, V>(predicate: (value: NoInfer<V>, key: NoInfer<K>) => boolean) => (self: HM.HashMap<K, V>) => boolean,
+  <K, V>(self: HM.HashMap<K, V>, predicate: (value: NoInfer<V>, key: NoInfer<K>) => boolean) => boolean
+>(2, (self, predicate) => Option.isSome(findFirst(self, predicate)))
+
 /** @internal */
 export const set = Dual.dual<
   <K, V>(key: K, value: V) => (self: HM.HashMap<K, V>) => HM.HashMap<K, V>,

packages/effect/test/HashMap.test.ts

@@ -94,6 +94,17 @@ describe("HashMap", () => {
     assertFalse(HM.hasHash(key(1), Hash.hash(key(0)))(map))
   })
 
+  it("hasBy", () => {
+    const map = HM.make([key(0), value("a")])
+
+    assertTrue(HM.hasBy(map, (v) => Equal.equals(v, value("a"))))
+    assertTrue(HM.hasBy(map, (_, k) => Equal.equals(k, key(0))))
+    assertTrue(pipe(map, HM.hasBy((v) => Equal.equals(v, value("a")))))
+    assertFalse(HM.hasBy(map, (v) => Equal.equals(v, value("b"))))
+    assertFalse(HM.hasBy(map, (_, k) => Equal.equals(k, key(1))))
+    assertFalse(pipe(map, HM.hasBy((v) => Equal.equals(v, value("b")))))
+  })
+
   it("get", () => {
     const map = HM.make([key(0), value("a")])