type-checking

We provide the signatures of a very limited number of standard library classes. We will really appreciate if you write the signature of other classes.

(Note that we are currently working for standard library signatures.)

Hi. I do not know is it real issue, but then my editor save BOM symbols in file(on Windows) Teal parser get error like this:

3 syntax errors:
sub\code2.tl:1:1: invalid token '∩'
sub\code2.tl:1:2: invalid token '╗'
sub\code2.tl:1:3: invalid token '┐'

There are quite a few functions in the repo that need to be annotated.
This issue will be left open for external contributions. If you wish to contribute, please submit a PR for the same!

Thanks!
-J