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62 lines
1.5 KiB
Text
62 lines
1.5 KiB
Text
interface Task
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exposes [ Task, succeed, fail, after, map, putLine, putInt, getInt, forever ]
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imports [ fx.Effect ]
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Task ok err : Effect.Effect (Result ok err)
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forever : Task val err -> Task c d
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forever = \task -> Effect.forever task
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succeed : val -> Task val *
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succeed = \val ->
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Effect.always (Ok val)
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fail : err -> Task * err
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fail = \val ->
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Effect.always (Err val)
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after : Task a err, (a -> Task b err) -> Task b err
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after = \effect, transform ->
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Effect.after
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effect
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\result ->
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when result is
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Ok a ->
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transform a
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Err err ->
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Task.fail err
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map : Task a err, (a -> b) -> Task b err
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map = \effect, transform ->
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Effect.map
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effect
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\result ->
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when result is
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Ok a ->
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Ok (transform a)
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Err err ->
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Err err
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putLine : Str -> Task {} *
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putLine = \line -> Effect.map (Effect.putLine line) (\_ -> Ok {})
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putInt : I64 -> Task {} *
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putInt = \line -> Effect.map (Effect.putInt line) (\_ -> Ok {})
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getInt : Task I64 []
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getInt =
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Effect.after
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Effect.getInt
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\{ isError, value, errorCode } ->
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when isError is
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True ->
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when errorCode is
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# A -> Task.fail InvalidCharacter
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# B -> Task.fail IOError
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_ ->
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Task.succeed -1
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False ->
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Task.succeed value
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