TypeScript Type Alias

type Identifier = TypeExpression;

// Primitive
type UUID = string;

// Object Shape
type Point = {
  x: number;
  y: number;
};

// Union
type State = "pending" | "resolved" | "rejected";

// Intersection
type SerializablePoint = Point & { toJSON(): string };

// Tuple
type Coordinates = [number, number, number];

// Function Signature
type Comparator = (a: number, b: number) => boolean;

type Result<T, E> = 
  | { success: true; data: T } 
  | { success: false; error: E };

type Dictionary<K extends string | number | symbol, V> = Record<K, V>;

type JSONValue = 
  | string 
  | number 
  | boolean 
  | null 
  | JSONValue[] 
  | { [key: string]: JSONValue };

type Entity = { id: string };

// Compiler Error: Duplicate identifier 'Entity'.
// type Entity = { createdAt: Date };