This PR removes the `NatCast (Fin n)` global instance (both the direct
instance, and the indirect one via `Lean.Grind.Semiring`), as that
instance causes causes `x < n` (for `x : Fin k`, `n : Nat`) to be
elaborated as `x < ↑n` rather than `↑x < n`, which is undesirable. Note
however that in Mathlib this happens anyway!
This PR adds a test case / use case example for `grind`, setting up the
very basics of `IndexMap`, modelled on Rust's
[`indexmap`](https://docs.rs/indexmap/latest/indexmap/). It is not
intended as a complete implementation: just enough to exercise `grind`.
(Thanks to @arthurpaulino for suggesting this as a test case.)
This PR fixes a bug in the equality-resolution procedure used by
`grind`.
The procedure now performs a topological sort so that every simplified
theorem declaration is emitted **before** any place where it is
referenced.
Previously, applying equality resolution to
```lean
h : ∀ x, p x a → ∀ y, p y b → x ≠ y
```
in the example
```lean
example
(p : Nat → Nat → Prop)
(a b c : Nat)
(h : ∀ x, p x a → ∀ y, p y b → x ≠ y)
(h₁ : p c a)
(h₂ : p c b) :
False := by
grind
```
caused `grind` to produce the incorrect term
```lean
p ?y a → ∀ y, p y b → False
```
The patch eliminates this error, and the following correct simplified
theorem is generated
```lean
∀ y, p y a → p y b → False
```
This PR fixes (1) an issue where private names are not unresolved when
they are pretty printed, (2) an issue where in `pp.universes` mode names
were allowed to shadow local names, (3) an issue where in `match`
patterns constants shadowing locals wouldn't use `_root_`, and (4) an
issue where tactics might have an incorrect "try this" when
`pp.fullNames` is set. Adds more delaboration tests for name
unresolution.
It also cleans up the `delabConst` delaborator so that it uses
`unresolveNameGlobalAvoidingLocals`, rather than doing any local context
analysis itself. The `inPattern` logic has been removed; it was a
heuristic added back in #575, but it now leads to incorrect results (and
in `match` patterns, local names shadow constants in name resolution).
This PR implements signature help support. When typing a function
application, editors with support for signature help will now display a
popup that designates the current (remaining) function type. This
removes the need to remember the function signature while typing the
function application, or having to constantly cycle between hovering
over the function identifier and typing the application. In VS Code, the
signature help can be triggered manually using `Ctrl+Shift+Space`.

### Other changes
- In order to support signature help for the partial syntax `f a <|` or
`f a $`, these notations now elaborate as `f a`, not `f a .missing`.
- The logic in `delabConstWithSignature` that delaborates parameters is
factored out into a function `delabForallParamsWithSignature` so that it
can be used for arbitrary `forall`s, not just constants.
- The `InfoTree` formatter is adjusted to produce output where it is
easier to identify the kind of `Info` in the `InfoTree`.
- A bug in `InfoTree.smallestInfo?` is fixed so that it doesn't panic
anymore when its predicate `p` does not ensure that both `pos?` and
`tailPos?` of the `Info` are present.
This PR provides the iterator combinator `drop` that transforms any
iterator into one that drops the first `n` elements.
Additionally, the PR removes the specialized `IteratorLoop` instance on
`Take`. It currently does not have a `LawfulIteratorLoop` instance,
which needs to exist for the loop consumer lemmas to work. Having the
specialized instance is low priority.
This PR adds `@[grind]` to `getElem?_pos` and variants.
I'd initially thought these would result in too much case splitting, but
it seems to be only minor, and in use cases the payoff is good.
This PR avoids the likely unexpected behavior of `removeDirAll` to
delete through symlinks and adds the new function
`IO.FS.symlinkMetadata`.
---------
Co-authored-by: Rob23oba <152706811+Rob23oba@users.noreply.github.com>
This PR sets `ring := true` by default in `grind`. It also fixes a bug
in the reification procedure, and improves the term internalization in
the ring and cutsat modules.
This PR clarifies the invalid field notation error when projected value
type is a metavariable.
Co-authored-by @sgraf812.
---------
Co-authored-by: Sebastian Graf <sg@lean-fro.org>
This PR clarifies the invalid dotted identifier notation error when the
type is a sort.
Co-authored-by @sgraf812.
---------
Co-authored-by: Joseph Rotella <7482866+jrr6@users.noreply.github.com>
This PR improves the rendering of hints in error messages by
consistently indenting diffs and splitting large diffs less granularly;
it also improves the ergonomics of `Lean.MessageData.hint`. Note that
the changes to the signature of `Lean.MessageData.hint` are breaking.
This PR depends on #8457.
This PR simplifies the interface between the `grind` core and the cutsat
procedure. Before this PR, core would try to minimize the number of
numeric literals that have to be internalized in cutsat. This
optimization was buggy (see `grind_cutsat_zero.lean` test), and produced
counterintuitive counterexamples.
This PR increases maxHeartbeats in the isDefEqProjIssue test, because
when running under the new compiler the `run_meta` call includes the
allocations of the compiler itself. With the old compiler, many of the
corresponding allocations were internal to C++ code and would not
increase the heartbeat count.
This PR provides array iterators (`Array.iter(M)`,
`Array.iterFromIdx(M)`), infinite iterators produced by a step function
(`Iter.repeat`), and a `ForM` instance for finite iterators that is
implemented in terms of `ForIn`.
This PR fixes the hash function used to implement congruence closure in
`grind`. The hash of an `Expr` must not depend on whether the expression
has been internalized or not.
This PR provides the iterator combinators `takeWhile` (forwarding all
emitted values of another iterator until a predicate becomes false)
`dropWhile` (dropping values until some predicate on these values
becomes false, then forwarding all the others).
This PR provides the iterator combinator `filterMap` in a pure and
monadic version and specializations `map` and `filter`. This new
combinator allows to apply a function to the emitted values of a stream
while filtering out certain elements.
`map` should have an optimized `IteratorCollect` implementation but it
turns out that this is not possible without a major refactor of
`IteratorCollect`: `toArrayMapped` requires a proof that the iterator is
finite. If `it.mapM f` is `Finite` but `it` is not, then such a proof
does not exist. `IteratorCollect` needs to take a proof that the loop
will terminate for the given monadic function `f` instead. This will not
be done in this PR.
This PR provides the `take` iterator combinator that transforms any
iterator into an iterator that stops after a given number of steps. The
change contains the implementation and lemmas.
`take` has a special implementation of `IteratorLoop` that relies on a
potentially more efficient `forIn` implementation of the inner iterator.
The mysterious `@[specialize]` on a test has been removed because it is
not necessary anymore according to a manual inspection of the IR. Either
I erroneously concluded from experiments that it was necessary of
something has changed in the meantime that makes it unnecessary.
This PR fixes two inappropriate uses of `whnfD` in `grind`. They were
potential performance foot guns, and were producing unexpected errors
since `whnfD` is not consistently used (and it should not be) in all
modules.
This PR fixes an issue when including a hard line break in a `Format`
that caused subsequent (ordinary) line breaks to be erroneously
flattened to spaces.
This issue is especially important for displaying notes and hints in
error messages, as these components could appear garbled due to improper
line-break rendering.
This PR implements `match`-expressions in `grind` using `match`
congruence equations. The goal is to minimize the number of `cast`
operations that need to be inserted, and avoid `cast` over functions.
The new approach support `match`-expressions of the form `match h : ...
with ...`.
This PR modifies the pretty printer so that dot notation is used for
class parent projections. Previously, dot notation was never used for
classes.
We still need to modify dot notation to take the method resolution order
into account when collapsing parent projections.
This PR removes the `@[reducible]` annotation on `Array.size`. This is
probably best gone anyway in order to keep separation between the `List`
and `Array` APIs, but it also helps avoid uselessly instantiating
`Array` theorems when `grind` is working on `List` problems.
This PR adds a `value_of% ident` term that elaborates to the value of
the local or global constant `ident`. This is useful for creating
definition hypotheses:
```lean
let x := ... complicated expression ...
have hx : x = value_of% x := rfl
```
This PR adds a feature to the `subst` tactic so that when `x : X := v`
is a local definition, `subst x` substitutes `v` for `x` in the goal and
removes `x`. Previously the tactic would throw an error.
This PR upstreams and extends the Mathlib `clear_value` tactic. Given a
local definition `x : T := v`, the tactic `clear_value x` replaces it
with a hypothesis `x : T`, or throws an error if the goal does not
depend on the value `v`. The syntax `clear_value x with h` creates a
hypothesis `h : x = v` before clearing the value of `x`. Furthermore,
`clear_value *` clears all values that can be cleared, or throws an
error if none can be cleared.