TypeScript Language Specification

[fljmayer]

Please supply an up-to-date TypeScript language specification. The only thing I could find was one for version 1.8 at https://github.com/microsoft/TypeScript/blob/master/doc/spec.md. I would like to parse TypeScript in a language other than JavaScript or TypeScript, preferably with ANTLR4, so I guess some formal grammar would do. I would think you have that somewhere in this project, but I cannot find it.

[MartinJohns]

Duplicate of #15711.

[fljmayer]

It's not exactly a duplicate. I just need some formal grammar to parse TypeScript. How would you parse TypeScript without that?

[MartinJohns]

There is no formal grammar available. You can look at the source of the compiler on how to parse TypeScript, or you can write a grammar yourself.

[fljmayer]

Could you please recommend an entry point where I can get an AST for a file or just a string containing TypeScript? Assuming there is some form of AST of course.

[weswigham]

ts.createSourceFile creates an AST.

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.

[fljmayer]

Thanks. Now I am trying to determine the type of a PropertyDeclaration in the SourceFile that only has an inititializer, no type. When I call TypeChecker.getContextualType() for the initializer expression it always returns undefined. Am I missing something?