cdbe29b46d
An important part of the interface of a function is the parameter names, for making used of named arguments. This PR makes the parameter names print in a reliable way. The parameters of the type now appear as hygienic names if they cannot be used as named arguments. Modifies the heuristic for how parameters are chosen to appear before or after the colon. The rule is now that parameters start appearing after the colon at the first non-dependent non-instance-implicit parameter that has a name unusable as a named argument. This is a refinement of #2846. Fixes the issue where consecutive hygienic names pretty print without a space separating them, so we now have `(x✝ y✝ : Nat)` rather than `(x✝y✝ : Nat)`. Breaking change: `Lean.PrettyPrinter.Formatter.pushToken` now takes an additional boolean `ident` argument, which should be `true` for identifiers. Used to insert discretionary space between consecutive identifiers. Closes #5810
73 lines
1.8 KiB
Text
73 lines
1.8 KiB
Text
|
||
/-!
|
||
This test checks if the functional induction principle has fewer universe parameters
|
||
if the original function has a parameter that disappears.
|
||
-/
|
||
|
||
namespace Structural
|
||
def foo.{u} : Nat → PUnit.{u}
|
||
| 0 => .unit
|
||
| n+1 => foo n
|
||
|
||
/--
|
||
info: Structural.foo.induct (motive : Nat → Prop) (case1 : motive 0) (case2 : ∀ (n : Nat), motive n → motive n.succ)
|
||
(a✝ : Nat) : motive a✝
|
||
-/
|
||
#guard_msgs in
|
||
#check foo.induct
|
||
|
||
example : foo n = .unit := by
|
||
induction n using foo.induct with
|
||
| case1 => unfold foo; rfl
|
||
| case2 n ih => unfold foo; exact ih
|
||
|
||
end Structural
|
||
|
||
namespace WellFounded
|
||
def foo.{u,v} {α : Type v} : List α → PUnit.{u}
|
||
| [] => .unit
|
||
| _ :: xs => foo xs
|
||
termination_by xs => xs
|
||
|
||
/--
|
||
info: WellFounded.foo.induct.{v} {α : Type v} (motive : List α → Prop) (case1 : motive [])
|
||
(case2 : ∀ (head : α) (xs : List α), motive xs → motive (head :: xs)) (a✝ : List α) : motive a✝
|
||
-/
|
||
#guard_msgs in
|
||
#check foo.induct
|
||
|
||
example : foo xs = .unit := by
|
||
induction xs using foo.induct with
|
||
| case1 => unfold foo; rfl
|
||
| case2 _ xs ih => unfold foo; exact ih
|
||
|
||
end WellFounded
|
||
|
||
|
||
namespace Mutual
|
||
mutual
|
||
def foo.{u} : Nat → PUnit.{u}
|
||
| 0 => .unit
|
||
| n+1 => bar n
|
||
termination_by n => n
|
||
def bar.{u} : Nat → PUnit.{u}
|
||
| 0 => .unit
|
||
| n+1 => foo n
|
||
termination_by n => n
|
||
end
|
||
|
||
/--
|
||
info: Mutual.foo.induct (motive1 motive2 : Nat → Prop) (case1 : motive1 0) (case2 : ∀ (n : Nat), motive2 n → motive1 n.succ)
|
||
(case3 : motive2 0) (case4 : ∀ (n : Nat), motive1 n → motive2 n.succ) (a✝ : Nat) : motive1 a✝
|
||
-/
|
||
#guard_msgs in
|
||
#check foo.induct
|
||
|
||
example : foo n = .unit := by
|
||
induction n using foo.induct (motive2 := fun n => bar n = .unit) with
|
||
| case1 => unfold foo; rfl
|
||
| case2 n ih => unfold foo; exact ih
|
||
| case3 => unfold bar; rfl
|
||
| case4 n ih => unfold bar; exact ih
|
||
|
||
end Mutual
|