Python from Wise Guy's Viewpoint

[Ed Avis]

prunesquallor at comcast.net writes:

>But let us suppose that someone improved the type system of Haskell
>such that some useful complicated constructs that did not pass the
>type checker were now able to be verified as correct.

Wouldn't you need to define the semantics for these constructs too?
And perhaps extend the compiler to generate code for them?

My original point was that the type-checker won't reject programs
which are valid Haskell, so it makes no sense to talk about the
checker being too strict or not allowing enough flexibility.  A
type-checker for some other language such as Lisp would obviously have
to not flag errors for any legal Lisp program.  (That would probably
mean not checking anything at all, with the programmer having to
explicitly state 'yes I don't want to wait until runtime to catch this
error'.)

-- 
Ed Avis <ed at membled.com>