🔌 primitive-types

Expressive low-level TypeScript types for integers, UUIDs, characters, etc.

let age: uint = 22;
age = -1;
  // ^ ❌ tsc(2322): Type '-1' is not assignable to type 'uint'.

let id: uuid = "01964bbf-a8b9-7710-9cea-3d6691b15689";
id = "abc-123";
  // ^ ❌ tsc(2322): Type '"abc-123"' is not assignable to type 'uuid<v>'.

[!TIP] Includes overloads and type-narrowing for built-ins like Math, Array, Date, Number, TypedArrays, and more.

💿 Install

Add package:

npm install primitive-types --save-dev

Enable types in tsconfig.json:

{
  "compilerOptions": {
    "types": [
      "primitive-types"
    ]
  }
}

Types

Arithmetic operations

In JavaScript all numbers are stored as 64-bit floating-point numbers or a 32-bit integers, and then represented as the dynamic number type.

The benefit of these opaque types is arithemetic is completely interchangable:

let a: uint8 = 10;
let b: int16 = -21_374;
let c: float64 = 4274.80;

let result = a * b / c;
// -50

And in-place arithmetic will naturally coerce variables to the number type too:

function isOver18(value: int8) {
    return value >= 18;
}

let age: int8 = 125;

isOver18(age)

age *= 2;
  // 'age' is coerced to 'number'

isOver18(age);
  // ^ ❌ tsc(2345): Argument of type 'number' is not assignable to parameter of type 'int8'.