The previous definition means it won't reduce until it's applied to
4 arguments which may have detrimental effects: ``f `on` fst`` would
for instance stay blocked, with some implicit arguments of the form
`DPair a b`. This means that `b` appears in a negative position in
the expression which may lead to positivity checking rejecting a
datatype defined using `on`!
I have decided to leave `g` and `f` on the LHS because I expect `on`
to be used either:
1. partially applied to two arguments
2. in a section if only applied to 1 and sections get eta-expanded
by the parser so that's fine.
Turns out that `Smaller` and `LT` won't unify because
1. the instance Sized Nat is not publicly exported
2. Smaller, and LT are stuck until fully applied
The given changes make that go away.
I can't make sense of this code, it seems to try to convert the
case function corresponding to `let (a, b) = f n in ...` into a
different case function where `f n` and `(a, b)` have been unified.
But if `f n` is a bona fide stuck computation, there's no chance of
this happening.
Just turning this off solves the #1782 and only breaks one function
in the whole of the idris2 repo (I would have expected our current
termination oracle to be too weak to detect it as valid anyway!)
and one in frex (which, again, should not have been seen as terminating).
Also fixes#1460
This is to make the bootstrap build with earlier versions of Chez - we
don't strictly need it because we don't use threads (yet) and some linux
distros only have Chez 9.5.
This is step 0 in a plan to use the scheme evaluator to evaluate Idris
expressions at compile time. As a proof of concept, I've got this
working for a toy language here: https://github.com/edwinb/SchemeEval
We won't be able to do anything interesting with this in Idris itself
until the next release because it involves updating the bootstrap code
and adding the ability to pass 'Integer' to foreign calls, which really
should have been allowed anyway since it's for a backend to decide what
it can cope with, not Idris itself.
In the `MkFix : f (Fix f) -> Fix f` example, using `Erased` for `f`
makes the type reduce to `[__] (Fix [__]) -> Fix [__]` and because
`[__] e1 ... en` computes to `[__]`, we end up with `[__] -> Fix [__]`
which does not reference `Fix` anymore.
We shouldn't strictly need this, but it doesn't do any harm, and it also
means we can use --inc chez in the build if we do. Let's see if it helps
or hinders the CI problem...
In theory argument elaboration order doesn't matter, but in practice we
sometimes make choices for performance reasons, like helping with
disambiguation by knowing the target type.
This was kind of messy, now we can more clearly see what's going on.
Also, more importantly, it gives us a bit more control which we
sometimes need. For example, if we go choose to go right to left for
some performance heuristic it might turn out we don't have enough
information yet, in which case we need to delay and try again later.
Fixes#1743
The `if then else` syntax expects a block for the `then` and `else`
parts. Before this patch, the token `InterpEnd` was not a valid
follow up token to end a block. This adds `InterpEnd` as a closing
token for blocks, allowing `if then else` in interpolation slices
without additional parens.
A few proofs have been rewritten, a few unnecessary cases cut, and
lots of unnecessary "explicit implicits" have been cut. Probably these
implicits were required when the code was initially written, and
inference has improved since then.
Instead of having an arbitrary looking priority number, record explicit
reasons for the delay, which helps order them sensibly when rerunning
them. Mostly this allows us to choose which ones to rerun, where it
helps, and helps order things to get better error messages.
`testInDir dir ...` lists all directories in `dir` which contains
`run` files, and such directories are considered tests.
This is done to make test addition/maintenance cheaper.
Convert some test directories to `testInDir`, but not all of them
because
* some directories are listed in several test groups
* other directories are have some tests disabled
