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41 lines
1 KiB
Text
41 lines
1 KiB
Text
interface Task
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exposes [ Task, succeed, fail, await, map, putLine, attempt ]
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imports [ fx.Effect ]
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Task ok err : Effect.Effect (Result ok err)
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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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await : Task a err, (a -> Task b err) -> Task b err
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await = \effect, transform ->
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Effect.after effect \result ->
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when result is
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Ok a -> transform a
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Err err -> Task.fail err
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attempt : Task a b, (Result a b -> Task c d) -> Task c d
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attempt = \effect, transform ->
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Effect.after effect \result ->
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when result is
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Ok ok -> transform (Ok ok)
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Err err -> transform (Err 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.after effect \result ->
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when result is
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Ok a -> Task.succeed (transform a)
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Err err -> Task.fail err
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putLine : Str -> Task {} *
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putLine = \line -> Effect.map (Effect.putLine line) (\_ -> Ok {})
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