This pr applies a number of fixes to the new typechecker.
The fixes implemented are:
1. When guessing the arity of the body, we properly use the type
information of the variables in the patterns.
2. When generating wildcards, we name them properly so that they align
with the name in the type signature.
3. When compiling named applications, we inline all clauses of the form
`fun : _ := body`. This is a workaround to
https://github.com/anoma/juvix/issues/2247 and
https://github.com/anoma/juvix/issues/2517
4. I've had to ignore test027 (Church numerals). While the typechecker
passes and one can see that the types are correct, there is a lambda
where its clauses have different number of patterns. Our goal is to
support that in the near future
(https://github.com/anoma/juvix/issues/1706). This is the conflicting
lambda:
```
mutual num : Nat → Num
:= λ : Nat → Num {| (zero : Nat) := czero
| ((suc n : Nat)) {A} := csuc (num n) {A}}
```
5. I've added non-trivial a compilation test involving monad
transformers.
## Overview
This PR makes the compiler pipeline thread-safe so that the test suite
can be run in parallel.
This is achieved by:
* Removing use of `{get, set, with}CurrentDir` functions.
* Adding locking around shared file resources like the the
global-project and internal build directory.
NB: **Locking is disabled for the main compiler target**, as it is
single threaded they are not required.
## Run test suite in parallel
To run the test suite in parallel you must add `--ta '+RTS -N -RTS'` to
your stack test arguments. For example:
```
stack test --fast --ta '+RTS -N -RTS'
```
The `-N` instructs the Haskell runtime to choose the number of threads
to use based on how many processors there are on your machine. You can
use `-Nn` to see the number of threads to `n`.
These flags are already [set in the
Makefile](e6dca22cfd/Makefile (L26))
when you or CI uses `stack test`.
## Locking
The Haskell package
[filelock](https://hackage.haskell.org/package/filelock) is used for
locking. File locks are used instead of MVars because Juvix code does
not control when new threads are created, they are created by the test
suite. This means that MVars created by Juvix code will have no effect,
because they are created independently on each test-suite thread.
Additionally the resources we're locking live on the filesystem and so
can be conveniently tagged by path.
### FileLock
The filelock library is wrapped in a FileLock effect:
e6dca22cfd/src/Juvix/Data/Effect/FileLock/Base.hs (L6-L8)
There is an [IO
interpreter](e6dca22cfd/src/Juvix/Data/Effect/FileLock/IO.hs (L8))
that uses filelock and an [no-op
interpreter](e6dca22cfd/src/Juvix/Data/Effect/FileLock/Permissive.hs (L7))
that just runs actions unconditionally.
### TaggedLock
To make the file locks simpler to use a TaggedLock effect is introduced:
e6dca22cfd/src/Juvix/Data/Effect/TaggedLock/Base.hs (L5-L11)
And convenience function:
e6dca22cfd/src/Juvix/Data/Effect/TaggedLock.hs (L28)
This allows an action to be locked, tagged by a directory that may or
may not exist. For example in the following code, an action is performed
on a directory `root` that may delete the directory before repopulating
the files. So the lockfile cannot be stored in the `root` itself.
e6dca22cfd/src/Juvix/Extra/Files.hs (L55-L60)
## Pipeline
As noted above, we only use locking in the test suite. The main app
target pipeline is single threaded and so locking is unnecessary. So the
interpretation of locks is parameterised so that locking can be disabled
e6dca22cfd/src/Juvix/Compiler/Pipeline/Run.hs (L64)
- Depends on #2481
This pr allows inductive type parameters to be any type. Until now, they
had to be exactly `Type`. This allows us to define more general traits
such as the `Monad` and `Functor`, as shown in the new test.
This is only supported under the temporary `--new-typechecker` flag.
Pending work:
Update the positivity checker if necessary (@jonaprieto).
Update the necessary compilation steps in Core (@lukaszcz).
Add compilation tests.
- Closes#2362
This pr implements a new typechecking algorithm. This algorithm can be
activated using the global flag `--new-typechecker`. This flag will only
take effect on the compilation pipeline but not the repl.
The main difference between the new and old algorithm is that the new
one inserts holes during typechecking. Thus, it does not require the
arity checker pass.
The new algorithm does not yet implement default arguments. The plan is
to make the change in the following steps:
1. Merge this pr.
2. Merge #2506.
3. Implement default arguments for the new algorithm.
4. Remove the arity checker and the old algorithm.
---------
Co-authored-by: Łukasz Czajka <62751+lukaszcz@users.noreply.github.com>
