On Wednesday, 26 September 2012 at 23:02:45 UTC, Piotr Szturmaj
wrote:
Jonathan M Davis wrote:
It sounds to me like the reason that structural typing is
needed is because
Tuple allows you to name its fields, which I've always thought
was a bad idea,
and which a built-in tuple definitely wouldn't do. If you
couldn't name its
fields, then any Tuple containing the same sequence of types
would be the same
type. So, the problem is caused by a feature that built-in
tuples wouldn't
even have.
Exactly my PoV. I think that "tuples with named fields" should
be anonymous structs and pure tuples shouldn't have named
fields.
I agree.
Tuples do *not* have field names. (I'm also not sure they should
support slicing either).
structural compound types with field names are called "records"
in FP and they are a completely separate concept from tuples. We
really should not conflate the two and I agree that nameless
structs are the perfect vehicle to support record types.
One of D's strongest design decisions was to separate structs
from classes which is a huge win. Why do we want to go back on
that with regards to this very similar use case?
