 | DeepArrow-0.2: Arrows for "deep application" | Contents | Index |
| Control.Arrow.DeepArrow.Examples |
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| Contents |
DeepArrow examples.
The types in the source code are formatted for easier reading.
| deep :: DeepArrow ~> => (c ~> c') -> (a -> (f, b -> (c, g)), e) ~> (a -> (f, b -> (c', g)), e) |
| extF :: DeepArrow ~> => (d ~> (c -> b)) -> (e -> (a, d), f) ~> (c -> (e -> (a, b), f)) |
| extFF :: DeepArrow ~> => (e -> (a, c -> b), f) ~> (c -> (e -> (a, b), f)) |
| extI :: DeepArrow ~> => (((a, (b, e)), c) -> d) ~> (b -> ((a, e), c) -> d) |
| extFI :: DeepArrow ~> => (e -> (g, ((a, (b, e)), c) -> d), f) ~> (b -> (e -> (g, ((a, e), c) -> d), f)) |
Given a value of type (a -> (f,b -> (c,g)),e), apply a function to just the c part and leave the rest intact.
deep = first . result . second . result . first
Given a way to extract a function from a d value, create a way to extract a function from a (e -> (a,d), f) value.
extF = funFirst . funResult . funSecond
To make an extractor, simply apply the extractor-transformer extF to the identity arrow.
extFF = extF idA
Extract a b input from a ((a,(b,e)),c) argument.
extI = (inpFirst . inpSecond) inpF
Typically, we will have to combine function and input extractors. For instance, combine extF and extI.
extFI = extF extI