b6399e18c3
This PR adds support for decidable equality of empty lists and empty arrays. Decidable equality for lists and arrays is suitably modified so that all diamonds are definitionally equal. Following #9302, the strong condition of definitionally equal under `with_reducible_and_instances` is tested. This also moves some of the comments added in #9302 out of docstrings. --------- Co-authored-by: Aaron Liu <aaronliu2008@outlook.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com>
28 lines
778 B
Text
28 lines
778 B
Text
def optL (a : Option α) := if a = .none then 1 else 2
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def optR (a : Option α) := if .none = a then 1 else 2
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/-- info: 1 -/
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#guard_msgs in #eval @optL Nat .none
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/-- info: 2 -/
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#guard_msgs in #eval optL (some ())
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/-- info: 1 -/
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#guard_msgs in #eval @optR Bool .none
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/-- info: 2 -/
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#guard_msgs in #eval optR (some 1.5)
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-- test instance diamonds
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example :
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@Option.decidableEqNone α none = @Option.decidableNoneEq α none := by
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with_reducible_and_instances rfl
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section
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variable {α : Type u} [DecidableEq α]
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example (x : Option α) :
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Option.instDecidableEq x none = Option.decidableEqNone x := by
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with_reducible_and_instances rfl
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example (x : Option α) :
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Option.instDecidableEq none x = Option.decidableNoneEq x := by
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with_reducible_and_instances rfl
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end
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