https://github.com/mikea/ts-types

A TypeScript Types Manipulation Library
https://github.com/mikea/ts-types

types typescript typescript-library

Last synced: about 2 months ago
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A TypeScript Types Manipulation Library

• Host: GitHub
• URL: https://github.com/mikea/ts-types
• Owner: mikea
• License: other
• Created: 2018-06-23T23:16:52.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2023-07-19T12:28:13.000Z (over 1 year ago)
• Last Synced: 2024-10-14T18:32:12.114Z (3 months ago)
• Topics: types, typescript, typescript-library
• Language: TypeScript
• Size: 124 KB
• Stars: 1
• Watchers: 1
• Forks: 1
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# ts-types

A TypeScript type manipulation library. It is a types-only library, i.e. it has 0 runtime code.

## Predicates

Predicates are types that are resolved to true or false:

```typescript

type P1 = IsNotNull;

type P2 = Or, IsString>;

```

Predicate combinators are defined in [`Predicates.ts`](./src/Predicates.ts).

Predicates for primitive types are defined in [`PrimitiveTypes.ts`](./src/PrimitiveTypes.ts).

Type equality predicate `Eq` can be used with assertions to test type results.

## Assertions

Predicate value can be asserted during compilation time:

```typescript

let _assert_null = AssertTrue>;

// user-defined predicates

let _assert_p1 = AssertTrue>;

let _assert_p2 = AssertFalse>;

```

## Objects Manipulation

Pick or reject properties of a given type:

```typescript

interface Person { name: string; age: number; }

type StringProps = PropertiesOfType;

let _assert_props = AssertTrue>

```

## Type Tags

Store type information in values:

```typescript

type Descriptor = { name: string } & WithTag<"t", T>;

const stringDescription: Descriptor = { name: "string" }; // no new storage

let t: GetTag<"t", typeof stringDescription>;

```