This PR adjusts the experimental module system to make `private` the
default visibility modifier in `module`s, introducing `public` as a new
modifier instead. `public section` can be used to revert the default for
an entire section, though this is more intended to ease gradual adoption
of the new semantics such as in `Init` (and soon `Std`) where they
should be replaced by a future decl-by-decl re-review of visibilities.
This PR adds a generic `MonadLiftT Id m` instance. We do not implement a
`MonadLift Id m` instance because it would slow down instance resolution
and because it would create more non-canonical instances. This change
makes it possible to iterate over a pure iterator, such as `[1, 2,
3].iter`, in arbitrary monads.
This PR changes the `show t` tactic to match its documentation.
Previously it was a synonym for `change t`, but now it finds the first
goal that unifies with the term `t` and moves it to the front of the
goal list.
This PR upstreams the `LawfulMonadLift(T)` classes, lemmas and instances
from Batteries into Core because the iterator library needs them in
order to prove lemmas about the `mapM` operator, which relies on
`MonadLiftT`.
This PR adds the `@[expose]` attribute to many functions (and changes
some theorems to be by `:= (rfl)`) in preparation for the `@[defeq]`
attribute change in #8419.
This PR reworks the `simp` set around the `Id` monad, to not elide or
unfold `pure` and `Id.run`
In particular, it stops encoding the "defeq abuse" of `Id X = X` in the
statements of theorems, instead using `Id.run` and `pure` to pass back
and forth between these two spellings. Often when writing these with
`pure`, they generalize to other lawful monads; though such changes were
split off to other PRs.
This fixes the problem with the current simp set where `Id.run (pure x)`
is simplified to `Id.run x`, instead of the desirable `x`.
This is particularly bad because the` x` is sometimes inferred with type
`Id X` instead of `X`, which prevents other `simp` lemmas about `X` from
firing.
Making `Id` reducible instead is not an option, as then the `Monad`
instances would have nothing to key on.
---------
Co-authored-by: Sebastian Graf <sg@lean-fro.org>
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR adjusts the experimental module system to not export the bodies
of `def`s unless opted out by the new attribute `@[expose]` on the `def`
or on a surrounding `section`.
---------
Co-authored-by: Markus Himmel <markus@lean-fro.org>
This PR adds an initial set of `@[grind]` annotations for
`List`/`Array`/`Vector`, enough to set up some regression tests using
`grind` in proofs about `List`. More annotations to follow.
This PR adds `instance [Pure f] : Inhabited (OptionT f α)`, so that
`Inhabited (OptionT Id Empty)` synthesizes.
Co-authored-by: Sebastian Graf <sg@lean-fro.org>
This PR adds missing docstrings and makes docstring style consistent for
`ForM`, `ForIn`, `ForIn'`, `ForInStep`, `IntCast`, and `NatCast`.
---------
Co-authored-by: Siddharth <siddu.druid@gmail.com>
This PR does some stage0 cleanup after #7100, and enables a warning when
the old `structure S extends P : Type` syntax is used. It also updates
the library to put resulting types in the new correct place (`structure
S : Type extends P`).
The `structure` elaborator also has some additional docstrings, and
`StructFieldKind.fromParent` is renamed to
`StructFieldKind.fromSubobject`.
This PR extend the preprocessing of well-founded recursive definitions
to bring assumptions like `h✝ : x ∈ xs` into scope automatically.
This fixes#5471, and follows (roughly) the design written there.
See the module docs at `src/Lean/Elab/PreDefinition/WF/AutoAttach.lean`
for details on the implementation.
This only works for higher-order functions that have a suitable setup.
See for example section “Well-founded recursion preprocessing setup” in
`src/Init/Data/List/Attach.lean`.
This does not change the `decreasing_tactic`, so in some cases there is
still the need for a manual termination proof some cases. We expect a
better termination tactic in the near future.
This PR completes the alignment of lemmas about monadic functions on
`List/Array/Vector`. Amongst other changes, we change the simp normal
form from `List.forM` to `ForM.forM`, and correct the definition of
`List.flatMapM`, which previously was returning results in the incorrect
order. There remain many gaps in the verification lemmas for monadic
functions; this PR only makes the lemmas uniform across
`List/Array/Vector`.
This PR adds to helper lemmas in the `LawfulMonad` namespace, which
sometimes fire via `simp` when the original versions taking
`LawfulApplicative` or `Functor` do not fire.
There are many more lemmas about `foldlM`, so this may be useful for
reasoning about for loops by transforming them into folds.
The transformation includes accounting for monad effects, but does have
a mild performance difference in that short-circuiting on
`ForInStep.done` is replaced by traversing the rest of the list with a
noop.
I'd previously added an instance from `ForIn'` to `ForIn`, but this then
caused some non-defeq duplication. It seems fine to just remove the
concrete `ForIn` instances in cases where the `ForIn'` instance exists
too. We can even remove a number of type-specific lemmas in favour of
the general ones.
The linters in Batteries can be used to spot mistakes in Lean. See the
message on
[Zulip](https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/Go-to-def.20on.20typeclass.20fields.20and.20type-dependent.20notation/near/442613564).
These are the different linters with errors:
- unusedArguments:
There are many unused instance arguments, especially a redundant `[Monad
m]` is very common
- checkUnivs:
There was a problem with universes in a definition in
`Init.Control.StateCps`. I fixed it by adding a `variable` statement for
the implicit arguments in the file.
- defLemma:
many proofs are written as `def` instead of `theorem`, most notably
`rfl`. Because `rfl` is used as a match pattern, it must be a def. Is
this desirable?
The keyword `abbrev` is sometimes used for an alias of a theorem, which
also results in a def. I would want to replace it with the `alias`
keyword to fix this, but it isn't available.
- dupNamespace:
I fixed some of these, but left `Tactic.Tactic` and `Parser.Parser` as
they are as these seem intended.
- unusedHaveSuffices:
I cleaned up a few proofs with unused `have` or `suffices`
- explicitVarsOfIff:
I didn't fix any of these, because that would be a breaking change.
- simpNF:
I didn't fix any of these, because I think that requires knowing the
intended simplification order.
Implements a new method to generate instance names for anonymous
instances that uses a heuristic that tends to produce shorter names. A
design goal is to make them relatively unique within projects and
definitely unique across projects, while also using accessible names so
that they can be referred to as needed, both in Lean code and in
discussions.
The new method also takes into account binders provided to the instance,
and it adds project-based suffixes. Despite this, a median new name is
73% its original auto-generated length. (Compare: [old generated
names](https://gist.github.com/kmill/b72bb43f5b01dafef41eb1d2e57a8237)
and [new generated
names](https://gist.github.com/kmill/393acc82e7a8d67fc7387829f4ed547e).)
Some notes:
* The naming is sensitive to what is explicitly provided as a binder vs
what is provided via a `variable`. It does not make use of `variable`s
since, when names are generated, it is not yet known which variables are
used in the body of the instance.
* If the instance name refers to declarations in the current "project"
(given by the root module), then it does not add a suffix. Otherwise, it
adds the project name as a suffix to protect against cross-project
collisions.
* `set_option trace.Elab.instance.mkInstanceName true` can be used to
see what name the auto-generator would give, even if the instance
already has an explicit name.
There were a number of instances that were referred to explicitly in
meta code, and these have been given explicit names.
Removes the unused `Lean.Elab.mkFreshInstanceName` along with the
Command state's `nextInstIdx`.
Fixes#2343
This is a rewrite of the `UnusedVariables` lint to inline and simplify
many of the dependent functions to try to improve the performance of
this lint, which quite often shows up in perf reports.
* The mvar assignment scanning is one of the most expensive parts of the
process, so we do two things to improve this:
* Lazily perform the scan only if we need it
* Use an object-pointer hashmap to ensure that we don't have quadratic
behavior when there are many mvar assignments with slight differences.
* The dependency on `Lean.Server` is removed, meaning we don't need to
do the LSP conversion stuff anymore. The main logic of reference finding
is inlined.
* We take `fvarAliases` into account, and union together fvars which are
aliases of a base fvar. (It would be great if we had `UnionFind` here.)
More docs will be added once we confirm an actual perf improvement.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
