c3a010a938
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.
68 lines
1.4 KiB
Text
68 lines
1.4 KiB
Text
/-!
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# Tests for issue #6400
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https://github.com/leanprover/lean4/issues/6400
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Nested field notation was not resolving correctly if there was generalized field notation coming first
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and the target wasn't the first explicit argument.
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-/
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/-!
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Example from issue #6400
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-/
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namespace Ex1
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structure S where
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x : Nat
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class Class where
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s : S
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def Class.foo [c : Class] : S := c.s
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-- Always worked
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example [c : Class] : S := c.foo
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-- Parens made it work
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example [c : Class] : Nat := (c.foo).x
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-- Formerly, "function expected at Class.foo"
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example [c : Class] : Nat := c.foo.x
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end Ex1
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/-!
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Fixed recursive calls too, which had the same problem.
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-/
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def Nat.f {n : Nat} : Nat :=
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match n with
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| 0 => 0
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| n + 1 => n.f.succ
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/-!
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Now instances are unfolded when searching for a relevant argument.
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-/
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namespace Ex2
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class Friend (α : Type) where
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friend : Type
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instance : Friend Nat where
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friend := Bool
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def _root_.Bool.f (b : Friend.friend Nat) := !b
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variable (a : Bool)
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/-- info: a.f : Bool -/
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#guard_msgs in #check a.f
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-- Semireducible definitions are not unfolded however.
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def semifriend (α : Type) [Friend α] := Friend.friend α
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def _root_.Bool.g (b : semifriend Nat) := !b
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/--
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error: invalid field notation, function 'Bool.g' does not have argument with type (Bool ...) that can be used, it must be explicit or implicit with a unique name
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-/
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#guard_msgs in #check a.g
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end Ex2
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