The names weren't fully explicit in the elaborator, so ambiguity
resolution wasn't able to take advantage of type-directed pruning. Now
they're explicit (but hard-coded, which we should fix later...) so they
can be resolved more easily.
Sorry for the less than informative title :). Lots going on here. It
started as an attempt to fix unification to deal with laziness coercions
in trickier places, but unearthed a couple of tricky and interconnected
issues that are hard to unpick into a single patch. So, this fixes a few
things:
- default hints should only be resolved on the current elaboration (e.g.
nested function definitions, not the outer definition which might not
yet be complete)
- delayed elaborators should be allowed to have nested delayed
elaborators, which means disambiguation is a little bit better
- we should delay elaborating arguments where the type isn't known yet,
because later arguments may resolve the type, and we can use this to
help with disambiguation/laziness coercions
- other bits and pieces arising
This prevents display of shadowed names from case blocks/where clauses
that are now unusable. It does mean that constraint arguments aren't
displayed, unless given an explicit name - this may not be good, since
we might want to know which constraints are in scope, so it may yet need
a little tweaking.
Now only abstracts over the environment once and deals with 'where'
clauses by rewriting the nested name with the rearranged environment. As
a result, it interacts far better with local definitions (i.e. where
blocks).
This is the result of running the command:
$ find . -name '*.idr' -type f -exec sed -i -E 's/\s+$//' {} +
I confirmed before running it that this would not affect any markdown
formatting in documentation comments.
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.
