483cad5fd6
This PR adds the attribute `@[univ_out_params]` for specifying which universe levels should be treated as output parameters. By default, any universe level that does not occur in any input parameter is considered an output parameter.
39 lines
1 KiB
Text
39 lines
1 KiB
Text
import Lean
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open Lean Meta
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@[univ_out_params v]
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class ToLvl₁.{u, v} : Type where
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dummy : ∀ (_ : Sort u) (_ : Sort v), True := fun _ _ => trivial
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/-- info: (some #[1]) -/
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#guard_msgs in
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run_meta do IO.println <| getOutLevelParamPositions? (← getEnv) ``ToLvl₁
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@[univ_out_params]
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class ToLvl₂.{u, v} : Type where
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dummy : ∀ (_ : Sort u) (_ : Sort v), True := fun _ _ => trivial
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/-- info: (some #[]) -/
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#guard_msgs in
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run_meta do IO.println <| getOutLevelParamPositions? (← getEnv) ``ToLvl₂
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@[univ_out_params v u]
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class ToLvl₃.{u, v} : Type where
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dummy : ∀ (_ : Sort u) (_ : Sort v), True := fun _ _ => trivial
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/-- info: (some #[0, 1]) -/
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#guard_msgs in
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run_meta do IO.println <| getOutLevelParamPositions? (← getEnv) ``ToLvl₃
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/-- error: `v` is not a universe parameter of `Foo` -/
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#guard_msgs in
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@[univ_out_params v]
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class Foo (α : Type u) where
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a : α
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/-- error: invalid `univ_out_params`, `Bla` is not a class -/
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#guard_msgs in
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@[univ_out_params u]
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structure Bla (α : Type u) where
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a : α
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