- https://typescript.codeplex.com adds a static typing scheme to JavaScript.
- http://definitelytyped.org provides a large repository of TypeScript definition files for JavaScript libraries.
- https://github.com/dart-lang/sdk/tree/master/pkg/js adds frictionless and typed interoperability with JavaScript APIs to Dart
Lets use TypeScript definitions (e.g. from DefinitelyTyped) to generate package:js declarations in Dart.
Given a example/dom.generated.d.ts containing
declare var name: string;
and a dart file example/dom.dart,
@DefinitelyTyped('example/dom.d.ts')
library dts2dart.example.example;
import 'package:definitely_typed/definitely_typed.dart';
part 'dom.g.dart';
the script bin/build.dart
$ dart bin/build.dart --full
generates example/dom.g.dart.
@JS()
external String get name;
Test it with
$ pub run test example --platform dartium,chrome
See the example folder in the repository.
- https://github.com/andrewray/DefinitelyMaybeTyped (a year ago) brings Typescript definition files to js_of_ocaml
- https://github.com/frenchy64/typescript-parser (2 years ago) TypeScript type declaration parser for ClojureScript
There is probably going to be a significant functionality overlap with https://github.com/angular/ts2dart (written in TypeScript, not Dart; can it transpile itself?).
- dart-lang/sdk#23423
- dart-lang/sdk#20215
- dart-lang/sdk#20189
- https://stackoverflow.com/questions/29606183/automate-javascript-interop-in-dart
It might be a good idea to preserve documentation comments when lexing and parsing
Declaration source files have a suffix .d.ts and contain only type definitions (see section 3 in TypeScript 1.6 specification) and ambient declarations (section 1.1 of the specification). See http://www.typescriptlang.org/Handbook#writing-dts-files to get a feel for it.
package:js provides a Js() annotation and there is an external keyword in dart 1.13-dev. Analyzer can typecheck calls to declared objects and dart2js generates efficient code that accesses them. See https://pub.dartlang.org/packages/js for the details.
Write everything in Dart. Create a vertical slice of the following functionality
- given a JavaScript file and a corresponding .t.ds file
- parse the .d.ts
- turn it into @JS external Dart code
- write it out
- use it to call something in the JavaScript file from Dart
then add features; then possibly break it into components: .t.ds parser, a source_gen generator class; add some more features; ... ???
- good error messages for .d.ts: use tested .d.ts files; write .d.ts files in an IDE that hints at errors as you make them; test with the TypeScript compiler.
- complete TypeScript parser: .d.ts files use only a subset of the full TypeScript syntax
For now see the example and tests. What is being tested works and vice versa.
- dts2dart, after ts2dart
- DefinitelyTyped or DefinitelyTyped.dart, after DefinitelyTyped
- annotate with @DefinitelyTyped("") or @TS("") or @DTS("")
I come to dislike dts2dart. It does not type well. Annotating with @DefinitelyTyped('filepath.d.ts') reads almost like a link, (at).
- Option 1: Do it in Dart. a) Use relevant parts of ts2dart, either as it is or try transpiling it to Dart. b) write something yourself
- Option 2: Use something in some other language, make it dump the AST in say JSON, load the AST
I am going with 1a) using code at https://github.com/robpike/ivy and https://github.com/unclebob/CC_SMC for inspiration.
- Option 1: https://github.com/dart-lang/source_gen and annotation that specifies what .d.ts I want to use; How to get the .d.ts?
- Option 2: generate Dart code for popular DefinitelyTyped .d.ts files and upload everything to Dart Pub
Option 1 is more concrete regarding what needs doing. I will be pursuing that. Option 2 has the advantage that it is me who discovers breakages caused by incompletely implemented parser, not the poor people trying to use the package.
- can parse https://github.com/Microsoft/TypeScript/blob/master/src/lib/dom.generated.d.ts
- can parse all DefinitelyTyped .d.ts files