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# Conflicts: # parser-typechecker/src/Unison/PrintError.hs # parser-typechecker/src/Unison/Typechecker/Context.hs # parser-typechecker/tests/Unison/Test/Typechecker.hs
33 lines
730 B
Plaintext
33 lines
730 B
Plaintext
--map/traverse
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effect Noop where
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noop : ∀ a . a -> {Noop} a
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effect Noop2 where
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noop2 : ∀ a . a -> a -> {Noop2} a
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type List a = Nil | Cons a (List a)
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map : ∀ a b e . (a -> {e} b) -> List a -> {e} (List b)
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map f as = case as of
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List.Nil -> List.Nil
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List.Cons h t -> List.Cons (f h) (map f t)
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c = List.Cons
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z : ∀ a . List a
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z = List.Nil
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ex = (c 1 (c 2 (c 3 z)))
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pure-map : List Text
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pure-map = map (a -> "hello") ex
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-- `map` is effect polymorphic
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zappy : () -> {Noop} (List UInt64)
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zappy u = map (zap -> (Noop.noop (zap UInt64.+ 1))) ex
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-- mixing multiple effects in a call to `map` works fine
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zappy2 : () -> {Noop, Noop2} (List UInt64)
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zappy2 u = map (zap -> Noop.noop (zap UInt64.+ Noop2.noop2 2 7)) ex
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()
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