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72 lines
1.5 KiB
Plaintext
72 lines
1.5 KiB
Plaintext
structural ability Emit a where
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emit : a ->{Emit a} ()
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structural type Stream e a r = Stream ('{e, Emit a} r)
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use Stream Stream
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use Optional None Some
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use Universal ==
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namespace Stream where
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step :
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(a ->{e} b) ->
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Request {Emit a} r ->{e, Emit b} r
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step f = cases
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{r} -> r
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{Emit.emit a -> k} ->
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Emit.emit (f a)
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handle k () with step f
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-- map : (a -> b) -> Stream {e} a r -> Stream {e} b r
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-- map : (a ->{e} b)
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-- -> Stream {e} a r
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-- -> Stream {e} b r
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-- 0. this gets a weird type
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map f s = Stream ' handle run s with step f
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-- 1. inferred type of `map` required an `o -> o` for some reason
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map1 f s =
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step f = cases
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{r} -> r
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{Emit.emit a -> k} ->
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Emit.emit (f a)
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handle k () with step f
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Stream ' handle run s with step f
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-- 2. gets the same weird type
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map2 f s =
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step :
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(a ->{e} b) ->
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Request {Emit a} r ->{e, Emit b} r
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step f = cases
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{r} -> r
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{Emit.emit a -> k} ->
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Emit.emit (f a)
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handle k () with step f
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Stream ' handle run s with step f
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run : Stream e a r ->{e, Emit a} r
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run = cases Stream c -> !c
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structural ability Abort where
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abort : {Abort} a
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---
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-- x : Stream {Abort} Nat ()
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x = Stream 'let
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Emit.emit 1
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Abort.abort
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Emit.emit 2
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---
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I found a value of type Var User "a"-94 where I expected to find one of type b96:
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24 | -> Stream {e} b r
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25 | map f s = Stream ' handle run s with step f
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from right here:
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22 | map : (a ->{e} b)
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