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.
23 lines
471 B
Text
23 lines
471 B
Text
def f (x : Nat) : IO Unit := do
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x -- Error
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IO.println x
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def f' (x : Nat) : IO Unit := do
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discard (pure x)
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IO.println x
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def g (xs : Array Nat) : IO Unit := do
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xs.set! 0 1 -- Error
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IO.println xs
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def g' (xs : Array Nat) : IO Unit := do
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discard <| pure (xs.set! 0 1)
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IO.println xs
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def h (xs : Array Nat) : IO Unit := do
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pure (xs.set! 0 1) -- Error
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IO.println xs
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def h' (xs : Array Nat) : IO Unit := do
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discard <| pure (xs.set! 0 1)
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IO.println xs
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