Programming

Chained Tuple Types

TypeScript 4.1’s variadic tuple types enable building complex type-safe data structures through method chaining, where each operation expands the chain’s type signature at compile time.

Self Modifying Type Predicates in Typescript

TypeScript’s type predicates can modify the type of this itself, enabling self-modifying type behavior that approaches dependent types. By implementing is<K extends keyof ShapeTypes>(type: K): this is ShapeTypes[K] on abstract classes, we achieve compile-time type narrowing where shape.is('circle') transforms the shape variable’s type from Shape to Circle, unlocking properties like shape.radius within conditional blocks.