Suppressing specific error and warnings

[pdesaulniers]

Related issue: teal-language/vscode-teal#41

The TypeScript compiler allows suppressing errors and warnings using a // @ts-ignore comment above the offending line:

var x: number = 123;

// @ts-ignore: The compiler will suppress the error below
x = "hello";

It also supports // @ts-nocheck at the top of files for suppressing errors in a whole file.

Would it make sense to add a similar feature in tl? I suppose it could be useful when migrating Lua codebases to Teal, to make the porting task more manageable.

Some potential concerns:

• Not sure if processing comments in the compiler is a good idea...
• These annotations could be handled by a separate tool, outside of the compiler.

[hishamhm]

I don't think the core compiler should process those comments, but perhaps the parser could preserve them for use by other tools as in the experimental preserve-comments branch. Still, that branch only stores the comments in the AST, it does not expose them via tl types. But I think Cyan for example is using the API, so it would be a matter of adding API functionality in that branch to obtain comments [*], if that's a feature that's wanted in the build tool.

[*] if we add a public API to read comments from the source, it would be good to consider also other use-cases such as documentation generation. (Is tealdoc using its own parser? @SovietKitsune ?)

[Sylviettee]

Tealdoc uses its own parser for comments by using the y position on each of the types.
Shiroko (a Teal linter) currently only looks at the end of a line for an ignore comment.

local x: someInvalidType -- shiroko: allow(tlCheck)