Add explicit types to some, none

bkiac · Nov 15, 2023 · 97c1ec8 · 97c1ec8
1 parent ed0eb2e
commit 97c1ec8
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Showing 2 changed files with 39 additions and 47 deletions.
diff --git a/src/option/none.ts b/src/option/none.ts
@@ -7,83 +7,79 @@ export class NoneImpl implements OptionMethods<never> {
 	readonly none = true
 	readonly value = null
 
-	and<U>(_other: Option<U>) {
+	and<U>(_other: Option<U>): None {
 		return None
 	}
 
-	andThen<U>(_f: (value: never) => Option<U>) {
+	andThen<U>(_f: (value: never) => Option<U>): None {
 		return None
 	}
 
 	expect(panic: string): never {
 		throw new Panic(panic)
 	}
 
-	filter(_f: (value: never) => boolean) {
+	filter(_f: (value: never) => boolean): None {
 		return None
 	}
 
-	inspect(_f: (value: never) => void) {
-		return this
+	inspect(_f: (value: never) => void): None {
+		return None
 	}
 
-	map<U>(_f: (value: never) => U) {
+	map<U>(_f: (value: never) => U): None {
 		return None
 	}
 
-	mapOr<A, B>(defaultValue: A, _f: (value: never) => B) {
+	mapOr<A, B>(defaultValue: A, _f: (value: never) => B): A {
 		return defaultValue
 	}
 
-	mapOrElse<A, B>(defaultValue: () => A, _f: (value: never) => B) {
+	mapOrElse<A, B>(defaultValue: () => A, _f: (value: never) => B): A {
 		return defaultValue()
 	}
 
-	or<U>(other: Option<U>) {
+	or<U>(other: Option<U>): Option<U> {
 		return other
 	}
 
-	orElse<U>(f: () => Option<U>) {
+	orElse<U>(f: () => Option<U>): Option<U> {
 		return f()
 	}
 
 	unwrap(): never {
-		throw new UnwrapPanic("Cannot unwrap on a None")
+		throw new UnwrapPanic(`called "unwrap()" on None`)
 	}
 
-	unwrapOr<U>(defaultValue: U) {
+	unwrapOr<U>(defaultValue: U): U {
 		return defaultValue
 	}
 
-	unwrapOrElse<U>(defaultValue: () => U) {
+	unwrapOrElse<U>(defaultValue: () => U): U {
 		return defaultValue()
 	}
 
-	xor<U>(other: Option<U>) {
+	xor<U>(other: Option<U>): Option<U> {
 		return other
 	}
 
-	get() {
-		return null
-	}
-
-	match<A, B>(_some: (value: never) => A, none: () => B) {
+	match<A, B>(_some: (value: never) => A, none: () => B): B {
 		return none()
 	}
 
-	toString() {
+	toString(): "None" {
 		return "None" as const
 	}
 
-	[inspectSymbol]() {
+	[inspectSymbol](): "None" {
 		return this.toString()
 	}
 
-	toObject() {
+	toObject(): {some: false; value: null} {
 		return {some: false, value: null} as const
 	}
 
-	toJSON() {
+	toJSON(): {meta: "None"; value: null} {
 		return {meta: "None", value: null} as const
 	}
 }

diff --git a/src/option/some.ts b/src/option/some.ts
@@ -11,84 +11,80 @@ export class SomeImpl<T> implements OptionMethods<T> {
 		this.value = value
 	}
 
-	and<U>(other: Option<U>) {
+	and<U>(other: Option<U>): Option<U> {
 		return other
 	}
 
-	andThen<U>(f: (value: T) => Option<U>) {
+	andThen<U>(f: (value: T) => Option<U>): Option<U> {
 		return f(this.value)
 	}
 
-	expect(_panic: string) {
+	expect(_panic: string): T {
 		return this.value
 	}
 
-	filter(f: (value: T) => boolean) {
+	filter(f: (value: T) => boolean): Option<T> {
 		return f(this.value) ? this : None
 	}
 
-	inspect(f: (value: T) => void) {
+	inspect(f: (value: T) => void): this {
 		f(this.value)
 		return this
 	}
 
-	map<U>(f: (value: T) => U) {
-		return Some(f(this.value))
+	map<U>(f: (value: T) => U): Some<U> {
+		return new SomeImpl(f(this.value))
 	}
 
-	mapOr<A, B>(_defaultValue: A, f: (value: T) => B) {
+	mapOr<A, B>(_defaultValue: A, f: (value: T) => B): B {
 		return f(this.value)
 	}
 
-	mapOrElse<A, B>(_defaultValue: () => A, f: (value: T) => B) {
+	mapOrElse<A, B>(_defaultValue: () => A, f: (value: T) => B): B {
 		return f(this.value)
 	}
 
-	or<U>(_other: Option<U>) {
+	or<U>(_other: Option<U>): this {
 		return this
 	}
 
-	orElse<U>(_f: () => Option<U>) {
+	orElse<U>(_f: () => Option<U>): this {
 		return this
 	}
 
-	unwrap() {
+	unwrap(): T {
 		return this.value
 	}
 
-	unwrapOr<U>(_defaultValue: U) {
+	unwrapOr<U>(_defaultValue: U): T {
 		return this.value
 	}
 
-	unwrapOrElse<U>(_defaultValue: () => U) {
+	unwrapOrElse<U>(_defaultValue: () => U): T {
 		return this.value
 	}
 
-	xor<U>(other: Option<U>) {
+	xor<U>(other: Option<U>): Option<T | U> {
 		return other.some ? None : this
 	}
 
-	get() {
-		return this.value
-	}
-
-	match<A, B>(some: (value: T) => A, _none: () => B) {
+	match<A, B>(some: (value: T) => A, _none: () => B): A {
 		return some(this.value)
 	}
 
-	toString() {
+	toString(): `Some(${string})` {
 		return `Some(${this.value})` as const
 	}
 
-	[inspectSymbol]() {
+	[inspectSymbol](): ReturnType<OptionMethods<T>["toString"]> {
 		return this.toString()
 	}
 
-	toObject() {
+	toObject(): {some: true; value: T} {
 		return {some: true, value: this.value} as const
 	}
 
-	toJSON() {
+	toJSON(): {meta: "Some"; value: T} {
 		return {meta: "Some", value: this.value} as const
 	}
 }