type-plus
Version:
Provides additional types for TypeScript.
99 lines • 3.85 kB
TypeScript
import type { IsAny } from '../any/any_type.js';
import type { IsNever } from '../never/never_type.js';
import type { IsObject } from '../object/object_type.js';
import type { Properties } from '../object/properties.js';
import type { And, Or } from '../predicates/logical.js';
import type { IsSymbol } from '../symbol/symbol_type.js';
type BothNever<A, B, Both, One, None> = And<IsNever<A>, IsNever<B>, Both, Or<IsNever<A>, IsNever<B>, One, None>>;
type BothAny<A, B, Both, One, None> = And<IsAny<A>, IsAny<B>, Both, Or<IsAny<A>, IsAny<B>, One, None>>;
type IdentityEqual<A, B, Then, Else> = (<_>() => _ extends (A & _) | _ ? 1 : 2) extends <_>() => _ extends (B & _) | _ ? 1 : 2 ? Then : Else;
/**
* Checks `A` and `B` are equal.
*
* ```ts
* type R = IsEqual<1, 1> // true
* type R = IsEqual<any, any> // true
* type R = IsEqual<boolean, boolean> // true
* type R = IsEqual<true, true> // true
* type R = IsEqual<[1], [1]> // true
*
* type R = IsEqual<boolean, true> // false
* type R = IsEqual<any, 1> // false
* type R = IsEqual<[any], [1]> // false
* type R = IsEqual<{ a: 1 }, { a: 1; b: 2 }> // false
* ```
*
* Note that intersection type checks only works at first level.
* It cannot be check recursively,
* or else will run into infinite recursion if the type includes recursive types.
*/
export type IsEqual<A, B, Then = true, Else = false> = [A, B] extends [B, A] ? BothNever<A, B, Then, Else, BothAny<A, B, Then, Else, IdentityEqual<A, B, Then, And<IsObject<A>, IsObject<B>, IdentityEqual<Properties<A>, Properties<B>, [
A,
B
] extends [(...args: infer P1) => any, (...args: infer P2) => any] ? IsEqual<P1, P2, Then, Else> : Then, Else>, [
A,
B
] extends [B, A] ? Then : Else>>>> : And<IsSymbol<A>, IsSymbol<B>, Then, Else>;
/**
* Checks `A` and `B` are not equal.
*
* ```ts
* type R = IsNotEqual<1, 1> // false
* type R = IsNotEqual<any, any> // false
* type R = IsNotEqual<boolean, boolean> // false
* type R = IsNotEqual<true, true> // false
* type R = IsNotEqual<[1], [1]> // false
*
* type R = IsNotEqual<boolean, true> // true
* type R = IsNotEqual<any, 1> // true
* type R = IsNotEqual<[any], [1]> // true
* type R = IsNotEqual<{ a: 1 }, { a: 1; b: 2 }> // true
* ```
*
* Note that intersection type checks only works at first level.
* It cannot be check recursively,
* or else will run into infinite recursion if the type includes recursive types.
*/
export type IsNotEqual<A, B, Then = true, Else = false> = IsEqual<A, B, Else, Then>;
/**
* Checks `A` and `B` are equal.
*
* @deprecated this will be changed to `filter` variant in the future.
* Please use `IsEqual` for the `predicate` behavior.
*
* ```ts
* type R = Equal<1, 1> // true
* type R = Equal<any, any> // true
* type R = Equal<boolean, boolean> // true
* type R = Equal<true, true> // true
* type R = Equal<[1], [1]> // true
*
* type R = Equal<boolean, true> // false
* type R = Equal<any, 1> // false
* type R = Equal<[any], [1]> // false
* type R = Equal<{ a: 1 }, { a: 1; b: 2 }> // false
* ```
*/
export type Equal<A, B, Then = true, Else = false> = IsEqual<A, B, Then, Else>;
/**
* Checks `A` and `B` are not equal.
*
* @deprecated this will be changed to `filter` variant in the future.
* Please use `IsNotEqual` for the `predicate` behavior.
*
* ```ts
* type R = NotEqual<1, 1> // false
* type R = NotEqual<any, any> // false
* type R = NotEqual<boolean, boolean> // false
* type R = NotEqual<true, true> // false
* type R = NotEqual<[1], [1]> // false
*
* type R = NotEqual<boolean, true> // true
* type R = NotEqual<any, 1> // true
* type R = NotEqual<[any], [1]> // true
* type R = NotEqual<{ a: 1 }, { a: 1; b: 2 }> // true
* ```
*/
export type NotEqual<A, B, Then = true, Else = false> = IsNotEqual<A, B, Then, Else>;
export {};
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