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Skip to contentValidate early. Release on every exit. A language is only useful
Start small.
TypeScript.Clearer flow.
Twill extends TypeScript with Swift-inspired syntax. Add guards, defer, trailing closures and checked switch expressions; keep TypeScript's types and compile to ordinary JavaScript.
TypeScript types · No language runtime · Experimental 0.1
workflow.twill.twill → TypeScript
twill
async function readOwned(acquire) {
const resource = await acquire();
defer {
await resource.close();
}
guard const name = await resource.read() else {
return 'Missing';
}
return name.toUpperCase();
}No language runtime
Native arrows, branches and framework APIs.
Your TypeScript types
Inference, narrowing and checked union cases.
One file at a time
Keep TS/JS imports and your existing build.
See what changes.
Small changes to the code you read every day.
TypeScript
ts
const user = findUser(id);
if (user == null) {
return 'Missing';
}
return user.name;Twill
twill
guard const user = findUser(id) else {
return 'Missing';
}
return user.name;Keep the successful path in view.
An explicit exit narrows the value for the rest of the scope. Nullish checks keep zero and false.
Read the semantics and tradeoffsA language is only useful
with its tools.
Write, check, format and debug in one working loop.
- Editor
- Completion, diagnostics, rename and source debugging.
- Quality
- TypeScript checking, Prettier and ESLint.
- Delivery
- Vite, Node ESM, source maps and native declarations.
Start small.
Keep your options open.
Use Twill where clearer control flow earns its place. Keep the rest of your project in TypeScript.