cd909b0a98
This PR adjusts the way the pretty printer unresolves names. It used to make use of all `export`s when pretty printing, but now it only uses `export`s that put names into parent namespaces (heuristic: these are "API exports" that are intended by the library author), rather than "horizontal exports" that put the names into an unrelated namespace, which the dot notation feature in #6189 now incentivizes. Closes the already closed #2524
33 lines
783 B
Text
33 lines
783 B
Text
def Set (α : Type) := α → Prop
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def Set.union (s₁ s₂ : Set α) : Set α :=
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fun a => s₁ a ∨ s₂ a
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def FinSet (n : Nat) := Set (Fin n)
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/-!
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The type of `x` is unfolded to find `Set.union`
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-/
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example (x y : FinSet 10) : FinSet 10 :=
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x.union y
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namespace FinSet
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export Set (union)
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end FinSet
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/-!
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Since the types are defeq, this alias works:
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-/
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example (x y : FinSet 10) : FinSet 10 :=
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FinSet.union x y
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/-!
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However, this dot notation fails since there is no `FinSet` argument.
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However, unfolding is the preferred method.
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-/
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/--
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error: invalid field notation, function 'Set.union' does not have argument with type (FinSet ...) 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
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example (x y : FinSet 10) : FinSet 10 :=
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x.union y
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