Allow `simproc`s to be declared without setting the `[simproc]`
attribute. A `simproc` declaration is function + pattern.
Motivation: allow them to be provided as arguments to `simp` **and** `simp only`.
TODO: track their use in `simp`.
TODO: builtin simprocs
Motivations:
- We can simplify the big mutual recursion and the implementation.
- We can implement the support for `match`-expressions in the `pre` method.
- It is easier to define and simplify `Simprocs`.
I was about to to address the TODO
/- TODO: check arity of the given function. If it takes a PSigma as the
last argument,
this function will produce incorrect results. -/
because we now have an arity-observing variant of `decodePackedArg?` in
`unpackArg` in `PackMutual`, and it would be prudent to use it here.
But I first wanted to create a test case that would actually exhibit
this corner case, and failed.
This code was added in 096e4eb6d0 and it had a test case, but not even
that test case seems to be actually using the `decodePackedArg?`
function, neither back then nor now.
Also, mathlib works without this code.
So this seems to be dead code, possibly due to other changes to the
system, and thus can be removed. A strategically place comments points
back to this PR in case we need to resurrect that code.
The pattern
```
for h : i in [:xs.size] do
let x := xs[i]'h.2
```
is occassionally useful to iterate over an array with the index in
hand. This PR extends the `get_elem_tactic_trivial` so that one can
simply write
```
for h : i in [:xs.size] do
let x := xs[i]
```
fixes#3032.
This removes checks in `Lean.Meta.reduceNat?` that caused it to fail on
terms it could handle because they contain meta variables in arguments.
This lead to those operations being reduced using their equational
definitions and slow performance on large patterns:
```
set_option profiler true
set_option profiler.threshold 1
def testMod (x:Nat) :=
match x with
| 128 % 1024 => true
| _ => false
-- elaboration took 3.02ms
def testMul (x:Nat) :=
match x with
| 128 * 1 => true
| _ => false
-- type checking took 11.1ms
-- compilation of testMul.match_1 took 313ms
-- compilation of testMul took 65.7ms
-- elaboration took 58.9ms
```
Performance is slower on `testMul` than `testMod` because `whnf` ends up
evaluateing `128 * 1` using Peano arithmetic while `128 % 1024` is able
to avoid that treatment since `128 < 1024`.
This makes hover info, go to definition, etc work for the `h` in `cases
h : e`. The implementation is similar to that used for the `generalize h
: e = x` tactic.
# Summary
This makes a small addition to our take on the LSP protocol
in the form of supporting snippet text edits.
It has been discussed
[here](https://github.com/microsoft/language-server-protocol/issues/592)
on the LSP issue tracker for a while,
but seems unlikely to be added anytime soon.
This feature was requested by @PatrickMassot for the purposes
of supporting Lean code templates in code actions and widgets.
---------
Co-authored-by: David Thrane Christiansen <david@davidchristiansen.dk>
There were no `quot_precheck` instances registered for the expression
tree elaborators, which prevented them from being usable in a `notation`
expansion without turning off the quotation prechecker.
Users can evaluate whether `set_option quotPrecheck false` is still
necessary for their `notation` definitions.
