What Is a Type-Level DSL
Use types to constrain a fluent API to valid programs.
What Is a Type-Level DSL?
A type-level DSL (domain-specific language) uses TypeScript types to constrain an API so that only valid programs compile. The types act as a grammar: invalid combinations are rejected before the code ever runs.
Embedded DSLs
An embedded DSL lives inside the host language (here, TypeScript) rather than being a separate parser. You write ordinary TS, but the type system enforces the DSL rules.
All lessons in this course
- What Is a Type-Level DSL
- Designing a Fluent Query DSL
- Compile-Time Input Validation
- Error Messages in Type-Level DSLs