Re:What Golang Is and Is Not
by catnaroek on Monday August 22, 2016 @05:23PM
(#12339554)
> eqtypes in SML are a botch
Standard ML's `eqtypes` aren't a bad idea at all:
(0) They ensure that `op=` can only be used on things that actually have decidable equality.
(1) If SML were to be equipped with dependent types in the future, it would make sense to only allow `eqtypes` as type indices. First-order unification can be used on syntactic values of `eqtypes`, so the basic architecture of a Damas-Milner type checker can be retained, in spite of having dependent types.
OTOH, equality and comparisons in OCaml are completely broken.
Standard ML's `eqtypes` aren't a bad idea at all:
(0) They ensure that `op=` can only be used on things that actually have decidable equality.
(1) If SML were to be equipped with dependent types in the future, it would make sense to only allow `eqtypes` as type indices. First-order unification can be used on syntactic values of `eqtypes`, so the basic architecture of a Damas-Milner type checker can be retained, in spite of having dependent types.
OTOH, equality and comparisons in OCaml are completely broken.