Fixes#132. When getting the names in the block, we need to return the
fully explicit name, because we can't assume they'll all be in the same
namespace as we can have namespaces inside parameters blocks.
Can't use a local which has 'erased' as its type, since that's just been
substituted in while working out how many arguments a local function
needs to have. Also need to ensure we've searched for default hints when
encountering IBindImplicits rather than after because otherwise it might
find the wrong instance.
Both these problems result it terms which don't type check getting past
the elaborator! So, also added a --debug-elab-check flag to check the
result of elaboration. It's not on by default because there are cases
where it really hurts performance, typically when inferring implicits
with lots of sharing. So we'll keep it as a debug flag, for now at
least.
See e.g. Applicative instance in Data.Vect. This allows implementations
to use implicits at run time (by default, they'd be 0 multiplicity so
erased, but it might be useful to have an index available at run time).
At the moment, the parser requires implicits to be given before
constraints. Ideally it should be possible to give them in any order.
I'll come back to this.
For the types of local names, don't write out the environment - it's
going to be repeated for every name, mostly it's unhelpful, and if you
want to see the types of other names you can ask directly. This can save
a huge amount of time when environments are slightly complicated.
If a default method implementation refers to another method in the
interface, it's going to be one from the interface being defined, so
push it through explicitly.
This is only going to be guaranteed to be the case for default method
implementations - we can't assume anything for other implementations.
Fixes#77
Sometimes we swap the arguments, to reduce code duplication, but we need
to remember we've done that since (1 x : a) -> b is valid for an
argument of type (x : a) -> b, but not vice versa (that is, we have a
teensy bit of subtying to deal with, for convenience...).
This fix seems a bit ugly, but we do at least now propagate the
information. Fixes#82.
This is supported by Idris 1 and is handy for breaking cycles in
modules. To achieve this, we just need to make sure that complete
definitions aren't overwritten with empty definitions on loading.
Checking the let expression in full can break sharing when unifying the
types, and it's unnecessary because we've already checked the type of
the scope unifies with the expected type.
Fixes#63
Elaborate the scope of a let without the computational behaviour,
meaning that `let x = v in e` is equivalent to `(\x => e) v`. This makes
things more consistent (in that let bindings already don't propagate
inside case or with blocks) at the cost of not being able to rely on the
computational behaviour in types. More importantly, it removes a
significant potential source of slowness.
Fixes#58
If you need the computational behaviour, you can use a local function
definition instead.
Fixes#42. If we don't do this, the name is treated in the saem way as
an unbound implicit, which is not what we want, so update with the
method applied to the parameters.
We were only doing implicits, so add auto implicits too. It's slightly
tricky, because we might also have implicits given of the form @{x}
which stands for the next auto implicit.
Fixes#50
Just like all other pi-bound things, if m is an unbound implicit and we
have m ?x = m y as a unification problem, we can conclude ?x = y because
it has to be true for all ms.
This was implemented in Blodwen but I hadn't got around to it yet for
Idris2... fortunately it's a bit easier in Idris2!
Fixes#44
We were only checking parameters, meaning that there were potential
clashes leading to confusing behaviour, and meaning that it was somehow
relevant what the names were in the interface!
Now by marking a method as multiplicity 0, we can explicitly say that
it's compile time only, so we can use it to compute types based on other
erased things - see tests/idris2/interface008 for a small example.
This fixes#8 - at least in that it allows the interface to be expressed
properly now, although the multiplicity annotations mean that
unfortunately it can't be compatible with Idris 1.
A local variable can't be applied to itself when searching (otherwise,
for example, we could end up trying something like id id id id id id etc
forever). So remove it from the environment before searching for its
arguments.
This and the previous patch fix#24. (Or, at least, the minimised cases
reported as part of it!)
We can't begin a search until we know what we're searching for! For some
reason I forgot to add this case, and without it the search space can
explode, or we might find an answer too soon and commit to the wrong
thing!
Fixes#36
This means that even if the relevant parameters aren't used by a method
body, the method can still see what the implicits are (though they will
be 0 multiplicity).
This is relevant to #8, but doesn't really fix it because we still need
a way of saying that methods are 0 multiplicity.
This is part of what we used to have in Enum but I think it's better to
separate the two. Added implementations for Nat, and anything in
Integral/Ord/Neg, so that we get range syntax (at least when its
implemeted) for the most useful cases.
This required a small change to auto implicit search (and I'm still not
sure about this). Now search arguments right to left, because solving
later arguments may resolve earlier arguments by unification and this
can happen in particular when chasing parent interfaces (which may have
fewer parameters).
Now supports with applications on the RHS when auto implicits are
involved. Auto implicit bound names in patterns now become searches on
the rhs in a with-application (I should write this construct up properly
in a paper some time!)
Elaborate via either === (homogeneous equality) or ~=~ (heterogeneous
equality) both of which are synonyms for Equal. This is to get the Idris
1 behaviour that equality is homogeneous by default to reduce the need
for type annotations, but heterogeneous if that doesn't work.
This was left over from Blodwen (where it was also wrong :)) but the way
we apply metavariables now means we don't need to do anything fancy when
unelaborating them for pretty printing.
