tmu
c7223dbe69
The fallback overload could not infer `R` from the handlers: `R` appeared only inside the `Exact` constraint, which is not an inference site, so with inferred handler params it collapsed to `unknown` and the matcher silently returned `UnaryFn<T, unknown>`. Adding `Partial<Handlers<T, R>>` to the handler parameter gives `R` an inference site, so the common return is inferred from the handlers and the fallback alike. Tests drop their explicit handler return annotations: real handlers are short and unannotated, and the common type is now inferred from them.
tiny-pattern-ts
Pattern matching for TypeScript/ESM environments (F#-style, not regex).
Description
tiny-pattern-ts brings F#-style pattern matching to TypeScript. Patterns are
ordinary objects whose matches method is a TypeScript type guard, so narrowing
composes the way any other guard does. It is deliberately not a regex engine and
not a macro: there is no transpiler and no DSL to learn, and the type-level
contract is the feature — see development/library.md
for the design decisions and the known limitations.
Requirements
- Node.js >= 26 (
enginesfield; pinned via.node-version). - TypeScript >= 5.0 to consume the published declarations. The emitted
.d.tsuseconsttype parameters (TS 5.0) and keep their relative.tsspecifiers; both resolve on TS >= 5.0 innode10/node16/nodenext/bundler. - The package is ESM-only (no CommonJS shim).
API
Yet to be implemented
License
MIT © 2025 tmu. See LICENSE.
Contributing
Contributions are documented in CONTRIBUTING.md; the reasons behind the project's decisions, rejected alternatives, and known issues live in development/. AI coding agents start at AGENTS.md.