e9d85f49e6
Based on the discussion at https://leanprover.zulipchat.com/#narrow/stream/270676-lean4/topic/for.2C.20unexpected.20need.20for.20type.20ascription/near/269083574 The consensus seemed to be that "auto pure" is more confusing than its worth.
10 lines
268 B
Text
10 lines
268 B
Text
import Lean
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open Lean
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def encodeDecode [ToJson α] [FromJson α] (x : α) : Except String α := do
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let json := toJson x
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fromJson? json
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#eval IO.ofExcept <| encodeDecode (Name.mkNum Name.anonymous 5)
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#eval IO.ofExcept <| encodeDecode (Name.mkStr `bla "foo.boo")
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