Adds support for `let_fun` to the `intro` and `intros` tactics. Also
adds support to `intro` for anonymous binder names, since the default
variable name for a `letFun` with an eta reduced body is anonymous.
Encouraged by the performance gains from making `rewrite` produce
smaller proof objects
(#3121) I am here looking for low-hanging fruit in `simp`.
Consider this typical example:
```
set_option pp.explicit true
theorem test
(a : Nat)
(b : Nat)
(c : Nat)
(heq : a = b)
(h : (c.add (c.add ((c.add b).add c))).add c = c)
: (c.add (c.add ((c.add a).add c))).add c = c
```
We get a rather nice proof term when using
```
:= by rw [heq]; assumption
```
namely
```
theorem test : ∀ (a b c : Nat),
@Eq Nat a b →
@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c →
@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c :=
fun a b c heq h =>
@Eq.mpr (@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c)
(@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c)
(@congrArg Nat Prop a b (fun _a => @Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c _a) c))) c) c) heq) h
```
(this is with #3121).
But with `by simp only [heq]; assumption`, it looks rather different:
```
theorem test : ∀ (a b c : Nat),
@Eq Nat a b →
@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c →
@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c :=
fun a b c heq h =>
@Eq.mpr (@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c)
(@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c)
(@id
(@Eq Prop (@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c)
(@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c))
(@congrFun Nat (fun a => Prop) (@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c))
(@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c))
(@congrArg Nat (Nat → Prop) (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c)
(Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) (@Eq Nat)
(@congrFun Nat (fun a => Nat) (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))))
(Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))))
(@congrArg Nat (Nat → Nat) (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c)))
(Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) Nat.add
(@congrArg Nat Nat (Nat.add c (Nat.add (Nat.add c a) c)) (Nat.add c (Nat.add (Nat.add c b) c)) (Nat.add c)
(@congrArg Nat Nat (Nat.add (Nat.add c a) c) (Nat.add (Nat.add c b) c) (Nat.add c)
(@congrFun Nat (fun a => Nat) (Nat.add (Nat.add c a)) (Nat.add (Nat.add c b))
(@congrArg Nat (Nat → Nat) (Nat.add c a) (Nat.add c b) Nat.add
(@congrArg Nat Nat a b (Nat.add c) heq))
c))))
c))
c))
h
```
Since simp uses only single-step `congrArg`/`congrFun` congruence lemmas
here, the proof
term grows very large, likely quadratic in this case.
Can we do better? Every nesting of `congrArg` (and it's little brother
`congrFun`) can be
turned into a single `congrArg` call.
In this PR I make making the smart app builders `Meta.mkCongrArg` and
`Meta.mkCongrFun` a bit
smarter and not only fuse with `Eq.refl`, but also with
`congrArg`/`congrFun`.
Now we get, in this simple example,
```
theorem test : ∀ (a b c : Nat),
@Eq Nat a b →
@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c →
@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c :=
fun a b c heq h =>
@Eq.mpr (@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c a) c))) c) c)
(@Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c b) c))) c) c)
(@congrArg Nat Prop a b (fun x => @Eq Nat (Nat.add (Nat.add c (Nat.add c (Nat.add (Nat.add c x) c))) c) c) heq) h
```
Let’s see if it works and how much we gain.
right now, the `induction` tactic accepts a custom eliminator using the
`using <ident>` syntax, but is restricted to identifiers. This
limitation becomes annoying when the elminator has explicit parameters
that are not targets, and the user (naturally) wants to be able to write
```
induction a, b, c using foo (x := …)
```
This generalizes the syntax to expressions and changes the code
accordingly.
This can be used to instantiate a multi-motive induction:
```
example (a : A) : True := by
induction a using A.rec (motive_2 := fun b => True)
case mkA b IH => exact trivial
case A => exact trivial
case mkB b IH => exact trivial
```
For this to work the term elaborator learned the `heedElabAsElim` flag,
`true` by default. But in the default setting, `A.rec (motive_2 := fun b
=> True)`
would fail to elaborate, because there is no expected type. So the
induction
tactic will elaborate in a mode where that attribute is simply ignored.
As a side effect, the “failed to infer implicit target” error message
is improved and prints the name of the implicit target that could not be
instantiated.
This PR adds support for the "call hierarchy" feature of LSP that allows
quickly navigating both inbound and outbound call sites of functions. In
this PR, "call" is taken to mean "usage", so inbound and outbound
references of all kinds of identifiers (e.g. functions or types) can be
navigated. To implement the call hierarchy feature, this PR implements
the LSP requests `textDocument/prepareCallHierarchy`,
`callHierarchy/incomingCalls` and `callHierarchy/outgoingCalls`.
<details>
<summary>Showing the call hierarchy (click to show image)</summary>
</details>
<details>
<summary>Incoming calls (click to show image)</summary>
</details>
<details>
<summary>Outgoing calls (click to show image)</summary>
</details>
It is based on #3159, which should be merged before this PR.
To route the parent declaration name through to the language server, the
`.ilean` format is adjusted, breaking backwards compatibility with
version 1 of the ILean format and yielding version 2.
This PR also makes the following more minor adjustments:
- `Lean.Server.findModuleRefs` now also combines the identifiers of
constants and FVars and prefers constant over FVars for the combined
identifier. This is necessary because e.g. declarations declared using
`where` yield both a constant (for usage outside of the function) and an
FVar (for usage inside of the function) with the same range, whereas we
would typically like all references to refer to the former. This also
fixes a bug introduced in #2462 where renaming a declaration declared
using `where` would not rename usages outside of the function, as well
as a bug in the unused variable linter where `where` declarations would
be reported as unused even if they were being used outside of the
function.
- The function converting `Lean.Server.RefInfo` to `Lean.Lsp.RefInfo`
now also computes the `Lean.DeclarationRanges` for parent declaration
names via `MetaM` and must hence be in `IO` now.
- Add a utility function `Array.groupByKey` to `HashMap.lean`.
- Stylistic refactoring of `Watchdog.lean` and `LanguageFeatures.lean`.
In the new snapshot design, we have a tree of `Task`s that represents
the asynchronously processed document structure. When transforming this
tree in response to a user edit, we want to quickly run through
reusable, already computed nodes of the tree synchronously and then
spawn new tasks for the new parts. The new flag allows us to do such
mixed sync/async tree transformations uniformly. This flag exists as
e.g.
[`ExecuteSynchronously`](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.taskcontinuationoptions?view=net-8.0)
in other runtimes.
I deleted internal links that seemed to have the character of "TODO". I
think that the residual TODO is of little value, given that we plan a
big revamp and revision soon anyway, but I could do it some other way as
well.
This makes changes to the definitions of Associativity, Commutativity,
Idempotence and Identity classes to be more aligned with Mathlib's
versions.
The changes are:
* Move classes are moved from `Lean` to root namespace.
* Drop `Is` prefix from names.
* Rename `IsNeutral` to `LawfulIdentity` and add Left and Right
subclasses.
* Change neutral/identity element to outParam.
* Introduce `HasIdentity` for operations not intended for proofs to
implement
The identity changes are to make this compatible with
[Mathlib](718042db9d/Mathlib/Init/Algebra/Classes.lean)
and to enable nicer fold operations in Std that can use type classes to
infer the identity/initial element on binary operations.
---------
Co-authored-by: Kyle Miller <kmill31415@gmail.com>
Makes the LLVM triple of the current platform available to Lean code
towards a solution for #2754.
Defaults to the empty string if the compiler is not clang, which can
introduce some divergence between CI and local builds but should not be
noticeable in most cases and is not really possible to avoid.
Recursive predefinitions contains “rec app” markers as mdata in the
predefinitions,
but sometimes these get in the way of termination checking, when you
have
```
[mdata (fun x => f)] arg
```
Therefore, the `preprocess` pass floats them out of applications
(originally
only for structural recursion, since #2818 also for well-founded
recursion).
But the code was incomplete: Because `Meta.transform` calls `post` on `f
x y` only
once (and not also on `f x`) one has to float out of nested applications
as well.
A consequence of this can be that in a recursive proof, `rw [foo]` does
not work
although `rw [foo _ _]` does.
Also adding the testcase where @david-christiansen and I stumbled over
this
(Maybe the two preprocess modules can be combined, now that #2973 is
landed, will try that
in a follow-up).
As suggested by @kmill, removing an unnecessary `let` (possibly only
there in the first place for copy/paste reasons) seems to fix the
included test.
This makes `~q()` matching in quote4 noticeably more useful in things
like `norm_num` (as it fixes
https://github.com/leanprover-community/quote4/issues/29)
It also makes a quote4 bug slightly more visible
(https://github.com/leanprover-community/quote4/issues/30), but the bug
there already existed anyway, and isn't caused by this patch.
Fixes#3065
Give n-ary `Expr.app` constructors such as `mkApp2`, `mkApp3`, ...,
`mkApp10` the `@[match_pattern]` attribute so that it is easier to read
and write pattern matching for applications.
This PR facilitates augmenting the context of an `InfoTree` with
*partial* contexts while elaborating a command. Using partial contexts,
this PR also adds support for tracking the parent declaration name of a
term in the `InfoTree`. The parent declaration name is needed to compute
the call hierarchy in #3082.
Specifically, the `Lean.Elab.InfoTree.context` constructor is refactored
to take a value of the new type `Lean.Elab.PartialContextInfo` instead
of a `Lean.Elab.ContextInfo`, which now refers to a full `InfoTree`
context. The `PartialContextInfo` is then merged into a `ContextInfo`
while traversing the tree using
`Lean.Elab.PartialContextInfo.mergeIntoOuter?`. The partial context
after executing `liftTermElabM` is stored in values of a new type
`Lean.Elab.CommandContextInfo`.
As a result of this, `Lean.Elab.ContextInfo.save` moves to
`Lean.Elab.CommandContextInfo.save`.
For obtaining the parent declaration for a term, a new typeclass
`MonadParentDecl` is introduced to save the parent declaration in
`Lean.Elab.withSaveParentDeclInfoContext`. `Lean.Elab.Term.withDeclName
x` now calls `withSaveParentDeclInfoContext x` to save the declaration
name.
### Migration
**The changes to the `InfoTree.context` constructor break backwards
compatibility with all downstream users that traverse the `InfoTree`
manually instead of going through the functions in `InfoUtils.lean`.**
To fix this, you can merge the outer `ContextInfo` in a traversal with
the `PartialContextInfo` of an `InfoTree.context` node using
`PartialContextInfo.mergeIntoOuter?`. See e.g.
`Lean.Elab.InfoTree.foldInfo` for an example:
```lean
partial def InfoTree.foldInfo (f : ContextInfo → Info → α → α) (init : α) : InfoTree → α :=
go none init
where go ctx? a
| context ctx t => go (ctx.mergeIntoOuter? ctx?) a t
| node i ts =>
let a := match ctx? with
| none => a
| some ctx => f ctx i a
ts.foldl (init := a) (go <| i.updateContext? ctx?)
| _ => a
```
Downstream users that manually save `InfoTree`s may need to adjust calls
to `ContextInfo.save` to use `CommandContextInfo.save` instead and
potentially wrap their `CommandContextInfo` in a
`PartialContextInfo.commandCtx` constructor when storing it in an
`InfoTree` or `ContextInfo.mk` when creating a full context.
### Motivation
As of now, `ContextInfo`s are always *full* contexts, constructed as if
they were always created in `liftTermElabM` after running the
`TermElabM` action. This is not strictly true; we already create
`ContextInfo`s in several places other than `liftTermElabM` and work
around the limitation that `ContextInfo`s are always full contexts in
certain places (e.g. `Info.updateContext?` is a crux that we need
because we can't always create partial contexts at the term-level), but
it has mostly worked out so far. Note that one must be very careful when
saving a `ContextInfo` in places other than `liftTermElabM` because the
context may not be as complete as we would like (e.g. it may lack
meta-variable assignments, potentially leading to a language server
panic).
Unfortunately, the parent declaration of a term is another example of a
context that cannot be provided in `liftTermElabM`: The parent
declaration is usually set via `withDeclName`, which itself lives in
`TermElabM`. So by the time we are trying to save the full
`ContextInfo`, the declaration name is already gone. There is no easy
fix for this like in the other cases where we would really just like to
augment the context with an extra field.
The refactor that we decided on to resolve the issue is to refactor the
`InfoTree` to take a `PartialContextInfo` instead of a `ContextInfo` and
have code that traverses the `InfoTree` merge inner contexts with outer
contexts to produce a full `ContextInfo` value.
### Bumps for downstream projects
- `lean-pr-testing-3159` branch at Std, not yet opened as a PR
- `lean-pr-testing-3159` branch at Mathlib, not yet opened as a PR
- https://github.com/leanprover/LeanInk/pull/57
- https://github.com/hargoniX/LeanInk/pull/1
- https://github.com/tydeu/lean4-alloy/pull/7
- https://github.com/leanprover-community/repl/pull/29
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
Currently we create `lean-pr-testing-NNNN` branches at Mathlib
automatically for each Lean PR.
We don't automatically create one at Std; mostly simply because Std
fails less often, so it has been okay to do this manually as needed. It
is conceptually simpler, however, if this is done uniformly.
This PR:
* does not proceed with Std/Mathlib CI unless the appropriate
`nightly-testing-YYYY-MM-DD` tag exists at Std (like it already doesn't
proceed if that tag is missing at Mathlib)
* creates `lean-pr-testing-NNNN` branches at Std
* when it creates `lean-pr-testing-NNNN` branches at Mathlib, updates
the Std dependency to use the `lean-pr-testing-NNNN` branch at Std
- [x] depends on #3199
Note that because most users do not have write access at Std, in order
to make updates to `lean-pr-testing-NNNN` branches there they will need
to make PRs. These will be merged with a very low bar, and feel free to
ping me for assistance on this. If this is annoying we will automate.
Also, frequent contributors to Lean may ask @digama0 or @joehendrix for
write access in order to easily work on these branches.
This PR requires that we have a secret here with write access at Std.
I'm arranging that [on
zulip](https://leanprover.zulipchat.com/#narrow/stream/348111-std4/topic/bot.20access/near/416686090).
I will update the documentation at
https://leanprover-community.github.io/contribute/tags_and_branches.html
to reflect these changes when they are merged.
---------
Co-authored-by: Joachim Breitner <mail@joachim-breitner.de>
As discussed during the FRO meeting 2024-01-18, we are changing the
`nightly-testing-YYYY-MM-DD` branches at Std and Mathlib from branches
to tags, in:
* https://github.com/leanprover/std4/pull/545
* https://github.com/leanprover-community/mathlib4/pull/9842
This PR updates the script that creates the `lean-pr-testing-NNNN`
branches at Mathlib so it is agnostic about whether
`nightly-testing-YYYY-MM-DD` will be a branch or a tag.
---------
Co-authored-by: Joachim Breitner <mail@joachim-breitner.de>
`Array.set!` and `Array.swap!` are fairly similar operations, both
modify an array, both take an index that it out of bounds.
But they behave different; all of these return `true`
```
#eval #[1,2].set! 2 42 == #[1,2] -- with panic
#reduce #[1,2].set! 2 42 == #[1,2] -- no panic
#eval #[1,2].swap! 0 2 == #[1,2] -- with panic
#reduce #[1,2].swap! 0 2 == default -- no panic
```
The implementations are
```
@[extern "lean_array_set"]
def Array.set! (a : Array α) (i : @& Nat) (v : α) : Array α :=
Array.setD a i v
```
but
```
@[extern "lean_array_swap"]
def swap! (a : Array α) (i j : @& Nat) : Array α :=
if h₁ : i < a.size then
if h₂ : j < a.size then swap a ⟨i, h₁⟩ ⟨j, h₂⟩
else panic! "index out of bounds"
else panic! "index out of bounds"
```
It seems to be more consistent to unify the behaviors, and define
```
@[extern "lean_array_swap"]
def swap! (a : Array α) (i j : @& Nat) : Array α :=
if h₁ : i < a.size then
if h₂ : j < a.size then swap a ⟨i, h₁⟩ ⟨j, h₂⟩
else a
else a
```
Also adds docstrings.
Fixes#3196
Consider
```
import Std.Tactic.ShowTerm
opaque a : Nat
opaque b : Nat
axiom a_eq_b : a = b
opaque P : Nat → Prop
set_option pp.explicit true
-- Using rw
example (h : P b) : P a := by show_term rw [a_eq_b]; assumption
```
Before, a typical proof term for `rewrite` looked like this:
```
-- Using the proof term that rw produces
example (h : P b) : P a :=
@Eq.mpr (P a) (P b)
(@id (@Eq Prop (P a) (P b))
(@Eq.ndrec Nat a (fun _a => @Eq Prop (P a) (P _a))
(@Eq.refl Prop (P a)) b a_eq_b))
h
```
which is rather round-about, applying `ndrec` to `refl`. It would be
more direct to write
```
example (h : P b) : P a :=
@Eq.mpr (P a) (P b)
(@id (@Eq Prop (P a) (P b))
(@congrArg Nat Prop a b (fun _a => (P _a)) a_eq_b))
h
```
which this change does.
This makes proof terms smaller, causing mild general speed up throughout
the code; if the brenchmarks don’t lie the highlights are
* olean size -2.034 %
* lint wall-clock -3.401 %
* buildtactic execution s -10.462 %
H'T to @digama0 for advice and help.
NB: One might even expect the even simpler
```
-- Using the proof term that I would have expected
example (h : P b) : P a :=
@Eq.ndrec Nat b (fun _a => P _a) h a a_eq_b.symm
```
but that would require non-local changes to the source code, so one step
at a time.
The `checkTargets` function introduced in 4a0f8bf2 as
```
checkTargets (targets : Array Expr) : MetaM Unit := do
let mut foundFVars : FVarIdSet := {}
for target in targets do
unless target.isFVar do
throwError "index in target's type is not a variable (consider using the `cases` tactic instead){indentExpr target}"
if foundFVars.contains target.fvarId! then
throwError "target (or one of its indices) occurs more than once{indentExpr target}"
```
looks like it tries to check for duplicate indices, but it doesn’t
actually, as `foundFVars` is never written to.
This adds
```
foundFVars := foundFVars.insert target.fvarId!
```
and a test case.
Maybe a linter that warns about `let mut` that are never writen to would
be useful?
I keep messing things up, so time for some guard rails, so check them
using
[actionlint](https://github.com/raven-actions/actionlint).
This also runs [shellcheck](https://www.shellcheck.net/) on the files.
Shellcheck
is a bit picky about putting double quotes around variables, and will
flag many
cases where we know it’s safe, but why not simply always write the safer
variant.
Unfortunately, actionlint does not (yet) check `actions/github-script`
scripts, which is
unfortunate. Maybe they will in the future
(https://github.com/rhysd/actionlint/issues/389)
there was a check
if !Structural.recArgHasLooseBVarsAt recFnName fixedPrefixSize e then
that would avoid going through `.refineThrough`/`.addArg` for
matcher/casesOn applications. It seems it tries to detect when refining
the motive/param is pointless, but it was too eager, and cause confusion
with, for example, this reasonably reasonable function:
def foo : (n : Nat) → (i : Fin n) → Bool
| 0, _ => false
| 1, _ => false
| _+2, _ => foo 1 ⟨0, Nat.zero_lt_one⟩
decreasing_by simp_wf; simp_arith
In particular, the `GuessLex` code later expects that the (implict)
`PProd.casesOn` in the implementation of `foo._unary` will refine the
paramter, because else the (rather picky) `unpackArg` fails. But it also
prevents this from being provable.
So let's try without this shortcut.
Fixing this also revealed that `withRecApps` wasn’t looking in all
corners
of a matcherApp/casesOnApp.
Fixes#3175
this didn’t recognize the new comments with an intro, and thus the bot
would post multiple comments.
The code was also out of sync with mathlib, fixing.
The `first(…)` in the `jq` program makes it more robust in case this
went wrong once (as on #3171) and there are now multiple PRs matching.
This uses the improved termination_by syntax to give Nat.gcd a cleaner
definition. It removes the last explicit use of WellFounded.fix in Init.
This was also partly motivated by leanprover/std4#520 so that unfold
Nat.gcd gives a sensible definition.
If the current manifest is from unsupported (or has errors), a bare
`lake update` will now discard it and create a new one from scratch
rather than erroring and requiring you to manually delete the manifest.
Lake will produce warnings noting it is ignoring such invalid manifests.
so far, our reference manual did not mention these at all, this takes
the discussion of recursive definition out of the “equation compiler”
section, put it into its own section, and expands it a bit.
This is more a MVP doc change to at least mention the features briefly,
and not the most polished and thought through didactic exposition. But
it provides a start for more improvements.
---------
Co-authored-by: Arthur Adjedj <arthur.adjedj@gmail.com>
Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
Co-authored-by: David Thrane Christiansen <david@davidchristiansen.dk>
This change
* moves `termination_by` and `decreasing_by` next to the function they
apply to
* simplify the syntax of `termination_by`
* apply the `decreasing_by` goal to all goals at once, for better
interactive use.
See the section in `RELEASES.md` for more details and migration advise.
This is a hard breaking change, requiring developers to touch every
`termination_by` in their code base. We decided to still do it as a
hard-breaking change, because supporting both old and new syntax at the
same time would be non-trivial, and not save that much. Moreover, this
requires changes to some metaprograms that developers might have
written, and supporting both syntaxes at the same time would make
_their_ migration harder.
This introduces `FilePath.addExtension` to take a path that we know has
no prior extension, and append a new extension to it.
As this function is simpler than `FilePath.withExtension`, this change
eagerly replaces uses of the latter with the former, except in a few
cases where stripping the extension really is the right thing to do.
This should fix the bug described at
https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/Import.20file.20with.20multiple.20dots.20in.20file.20name/near/404508048,
where `import «A.B».«C.D.lean»` is needed to import `A.B/C.D.lean`.
Closes#2999
---------
Co-authored-by: Mac Malone <tydeu@hatpress.net>
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
To handle delaborating notations that are functions that can be applied
to arguments, extracts the core function application delaborator as a
separate function that accepts the number of arguments to process and a
delaborator to apply to the "head" of the expression.
Defines `withOverApp`, which has the same interface as the combinator of
the same name from std4, but it uses this core function application
delaborator.
Uses `withOverApp` to improve a number of application delaborators,
notably projections. This means Mathlib can stop using `pp_dot` for
structure fields that have function types.
Incidentally fixes `getParamKinds` to specialize default values to use
supplied arguments, which impacts how default arguments are delaborated.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
