79930af11e
Now one can write `@x.f`, `@(x).f`, `@x.1`, `@(x).1`, and so on.
This fixes an issue where structure instance update notation (like `{x
with a := a'}`) could fail if the field `a` had a type with implicit,
optional, or auto parameters.
Closes #5406
99 lines
3.2 KiB
Text
99 lines
3.2 KiB
Text
/-!
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# Add explicit mode projections
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This is to fix a bug where structure instance notation was not working when there were opt params.
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-/
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/-!
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Motivating issue from https://github.com/leanprover/lean4/issues/5406
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The `example` had an elaboration error because the structure instance was expanding to `{b := m.b}`.
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Now it expands to `{b := @m.b}`.
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-/
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structure Methods where
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b : Nat → (opt : Nat := 42) → Nat
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example (m : Methods) : Methods := { m with }
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/-- info: fun m => { b := @Methods.b m } : Methods → Methods -/
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#guard_msgs in #check fun (m : Methods) => { m with }
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/-!
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Tests of explicit mode, with and without arguments.
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-/
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/-- info: fun m => @Methods.b m : Methods → Nat → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @m.b
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/-- info: fun m => @Methods.b m : Methods → Nat → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @(m).b
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/-- info: fun m => @Methods.b m : Methods → Nat → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @m.1
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/-- info: fun m => @Methods.b m : Methods → Nat → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @(m).1
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/-- info: fun m => @Methods.b m 1 : Methods → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @m.b 1
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/-- info: fun m => @Methods.b m 1 : Methods → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @(m).b 1
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/-- info: fun m => @Methods.b m 1 : Methods → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @m.1 1
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/-- info: fun m => @Methods.b m 1 : Methods → optParam Nat 42 → Nat -/
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#guard_msgs in #check fun (m : Methods) => @(m).1 1
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/-!
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Tests of explicit mode with class instances. The type parameter remains implicit.
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We need this so that structure instances work properly.
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-/
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class C (α : Type) [Inhabited α] where
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f (x : α := default) : α
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/-- info: fun inst => C.f : C Nat → Nat -/
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#guard_msgs in #check fun (inst : C Nat) => inst.f
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/-- info: fun inst => @C.f Nat instInhabitedNat inst : C Nat → optParam Nat default → Nat -/
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#guard_msgs in #check fun (inst : C Nat) => @inst.f
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/-- info: fun inst => @C.f Nat instInhabitedNat inst : C Nat → optParam Nat default → Nat -/
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#guard_msgs in #check fun (inst : C Nat) => @C.f _ _ inst
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/-- info: fun inst => { f := @C.f Nat instInhabitedNat inst } : C Nat → C Nat -/
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#guard_msgs in #check fun (inst : C Nat) => { inst with }
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/-!
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Tests of deeper updates and accesses.
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-/
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structure A (α : Type) where
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x : α
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structure B (α β : Type) extends A α where
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y : β
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/-- info: fun α β x' b => { x := x', y := b.y } : (α β : Type) → α → B α β → B α β -/
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#guard_msgs in #check fun (α β) (x' : α) (b : B α β) => {b with x := x'}
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/-- info: fun α β b => b.x : (α β : Type) → B α β → α -/
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#guard_msgs in #check fun (α β) (b : B α β) => @b.toA.x
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/-- info: fun α β b => b.x : (α β : Type) → B α β → α -/
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#guard_msgs in #check fun (α β) (b : B α β) => @b.x
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/-!
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Tests of implicit arguments in updates.
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-/
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structure I where
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f : {_ : Nat} → Nat
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-- used to give `fun i ↦ ?m.369 i : I → I`
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/-- info: fun i => { f := @I.f i } : I → I -/
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#guard_msgs in #check fun (i : I) => {i with}
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