Runtime checks of parametric annotations

[Jake Wheat]

Hi All,

Quoting from here: https://www.pyret.org/docs/latest/s_annotations.html

> To properly express the constraint on the contents, we need to specialize the list annotation:

>    list-of-nums :: List<Number> = [list: 1, 2, 3]

> Note that this annotation will not dynamically check that every item in the list is in fact a Number — that would be infeasibly expensive.

Is there any hope for a non-infeasibly expensive way to check annotations like this dynamically?

Thanks,
Jake.

[Shriram Krishnamurthi]

There are lazy approaches, like that discussed by Findler and others in ~2007. But we don't plan to add these to Pyret in the foreseeable future.

[Jake Wheat]

Thanks, I found some papers by Findler that look interesting.