> Pre-Scheme is strongly statically typed (with Hindley-Milner typing, not
> with declarations), so not that good a match for JS.

I didn't know that it uses H-M typing. I agree that it'd probably be
nicer to use dynamic typing to compiler to JS. (Elm is accomplishing
interesting JS feats with quite strict H-M typing, but it's a very
different world from Scheme.)

> Personally I've always thought that full-blast interprocedural HM is
> problematic: a little error and your code may typecheck, but the types
> assigned are not the types you expected!  As a matter of language
> design, I think it's better if procedure arguments and global variables
> always have to be explicitly typed; we shouldn't try to infer argument
> types from calls elsewhere in the program.

It does lead to weird types sometimes, but you can always fix it by
hand. The Elm compiler shows you all top-level types it inferred and
says, "if this type annotation looks right, please copy-paste it into
your code".