The array read and write operations are now called:
- "Comfortable" version (with runtime bound checks):
`Array.get` and `Array.set` like OCaml.
It is also consistent with `Ref.get` and `Ref.put`,
and `get` and `set` for `MonadState`.
- `Fin` version (without runtime bound checks):
`Array.index` and `Array.update` like in F*.
- `USize` version (without runtime bound checks and unboxing):
`Array.idx` and `Array.updt`.
cc @kha
`fix.lean` and `fix_1.lean` are very similar, but fix.lean is almost
twice as fast. Reason: `fix.lean` uses `fix_2` instead of `fix_1` and
avoid the creation of many closures. Here are runtime numbers on my
machine.
```
time ./fix_1.lean.out 23
352321527
real 0m0.729s
user 0m0.724s
sys 0m0.000s
```
```
~/projects/lean4/tests/playground (master +)$ time ./fix.lean.out 23
352321527
real 0m0.396s
user 0m0.388s
sys 0m0.004s
```
TODO: modify the compiler to replace `fix_core_n f a_1 ... a_m`
with `fix_core_m f a_1 ... a_m` whenever `n < m`.
This feature is quite useful for writing reusable/generic code. For
example, we cannot write an efficient `rec_t` without it because we
don't know the arity of `m A` when we write `rec_t`.
@kha
I am using this little program to generate big lean files to test the
new front end. For the output produced for `gen 5000`, the new frontend
is almost 10x slower than the old one.
I used `valgrind --tool=callgrind` to collect profiling data.
The number of closures is too big. For example, `free_closure_obj` was
invoked 38.5 million times. The total number of deallocated objects is around
49.5 million.
@kha I have disabled this check. It was implemented 2 years ago by
Daniel, and I don't want to fix it. It seems you have already fixed a
bug there. AFAICT, this check is just for improving error messages.
I believe we may not even need it since the kernel now supports nested
inductive types. AFAIR, Daniel implemented this check here because the
inductive compiler was introducing a lot of auxiliary declarations
that were making the kernel error messages unreadable.
@kha I tried to make the examples self contained.
- unionfind1.lean uses the modified StateT and ExceptT
- unionfind2.lean uses the standard StateT and ExceptT
