Array.window signature has been improved (#5679)

Author: KhraksMamtsov

.changeset/famous-breads-kiss.md

@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+`Array.window` signature has been improved

packages/effect/dtslint/Array.tst.ts

@@ -940,15 +940,26 @@ describe("Array", () => {
   })
 
   it("window", () => {
+    const two: number = 2
     // Array
-    expect(Array.window(strings, 2)).type.toBe<Array<Array<string>>>()
-    expect(pipe(strings, Array.window(2))).type.toBe<Array<Array<string>>>()
-    expect(Array.window(2)(strings)).type.toBe<Array<Array<string>>>()
+    expect(Array.window(strings, two)).type.toBe<Array<Array<string>>>()
+    expect(pipe(strings, Array.window(two))).type.toBe<Array<Array<string>>>()
+    expect(Array.window(two)(strings)).type.toBe<Array<Array<string>>>()
 
     // NonEmptyArray
-    expect(Array.window(nonEmptyStrings, 2)).type.toBe<Array<Array<string>>>()
-    expect(pipe(nonEmptyStrings, Array.window(2))).type.toBe<Array<Array<string>>>()
-    expect(Array.window(2)(nonEmptyStrings)).type.toBe<Array<Array<string>>>()
+    expect(Array.window(nonEmptyStrings, two)).type.toBe<Array<Array<string>>>()
+    expect(pipe(nonEmptyStrings, Array.window(two))).type.toBe<Array<Array<string>>>()
+    expect(Array.window(two)(nonEmptyStrings)).type.toBe<Array<Array<string>>>()
+
+    // literal + Array
+    expect(Array.window(strings, 2)).type.toBe<Array<[string, string]>>()
+    expect(pipe(strings, Array.window(2))).type.toBe<Array<[string, string]>>()
+    expect(Array.window(2)(strings)).type.toBe<Array<[string, string]>>()
+
+    // literal + NonEmptyArray
+    expect(Array.window(nonEmptyStrings, 2)).type.toBe<Array<[string, string]>>()
+    expect(pipe(nonEmptyStrings, Array.window(2))).type.toBe<Array<[string, string]>>()
+    expect(Array.window(2)(nonEmptyStrings)).type.toBe<Array<[string, string]>>()
   })
 
   it("reverse", () => {

packages/effect/dtslint/Types.tst.ts

@@ -3,6 +3,10 @@ import { describe, expect, it } from "tstyche"
 
 describe("Types", () => {
   it("TupleOf", () => {
+    expect<Types.TupleOf<-1, number>>()
+      .type.toBe<never>()
+    expect<Types.TupleOf<0, number>>()
+      .type.toBe<[]>()
     expect<Types.TupleOf<3, number>>()
       .type.toBe<[number, number, number]>()
   })

packages/effect/src/Array.ts

@@ -18,7 +18,7 @@ import * as Order from "./Order.js"
 import * as Predicate from "./Predicate.js"
 import * as Record from "./Record.js"
 import * as Tuple from "./Tuple.js"
-import type { NoInfer } from "./Types.js"
+import type { NoInfer, TupleOf } from "./Types.js"
 
 /**
  * @category type lambdas
@@ -2135,9 +2135,14 @@ export const chunksOf: {
  * @since 3.13.2
  */
 export const window: {
-  (n: number): <A>(self: Iterable<A>) => Array<Array<A>>
-  <A>(self: Iterable<A>, n: number): Array<Array<A>>
-} = dual(2, <A>(self: Iterable<A>, n: number): Array<Array<A>> => {
+  <N extends number = number>(
+    n: N
+  ): <A>(self: Iterable<A>) => Array<TupleOf<N, A>>
+  <A, N extends number = number>(
+    self: Iterable<A>,
+    n: N
+  ): Array<TupleOf<N, A>>
+} = dual(2, <A, const N extends number>(self: Iterable<A>, n: N): Array<Array<A>> => {
   const input = fromIterable(self)
   if (n > 0 && isNonEmptyReadonlyArray(input)) {
     return Array.from(

packages/effect/src/Types.ts

@@ -4,7 +4,9 @@
  * @since 2.0.0
  */
 
-type _TupleOf<T, N extends number, R extends Array<unknown>> = R["length"] extends N ? R : _TupleOf<T, N, [T, ...R]>
+type _TupleOf<T, N extends number, R extends Array<unknown>> = `${N}` extends `-${number}` ? never
+  : R["length"] extends N ? R
+  : _TupleOf<T, N, [T, ...R]>
 
 /**
  * Represents a tuple with a fixed number of elements of type `T`.