 | uniplate-1.6: Help writing simple, concise and fast generic operations. | Contents | Index |
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Data.Generics.Uniplate.Zipper |
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Description |
A zipper is a structure for walking a value and manipulating it in constant time.
This module was inspired by the paper:
Michael D. Adams. Scrap Your Zippers: A Generic Zipper for Heterogeneous Types, Workshop on Generic Programming 2010.
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Synopsis |
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Create a zipper and get back the value
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data Zipper from to |
Zipper structure, whose root type is the first type argument, and whose
focus type is the second type argument.
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zipper :: Uniplate to => to -> Zipper to to |
Create a zipper, focused on the top-left value.
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zipperBi :: Biplate from to => from -> Maybe (Zipper from to) |
Create a zipper with a different focus type from the outer type. Will return
Nothing if there are no instances of the focus type within the original value.
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fromZipper :: Zipper from to -> from |
From a zipper take the whole structure, including any modifications.
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Navigate within a zipper
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left :: Zipper from to -> Maybe (Zipper from to) |
Move one step left from the current position.
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right :: Zipper from to -> Maybe (Zipper from to) |
Move one step right from the current position.
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up :: Zipper from to -> Maybe (Zipper from to) |
Move one step up from the current position.
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down :: Uniplate to => Zipper from to -> Maybe (Zipper from to) |
Move one step down from the current position.
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Manipulate the zipper hole
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hole :: Zipper from to -> to |
Retrieve the current focus of the zipper..
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replaceHole :: to -> Zipper from to -> Zipper from to |
Replace the value currently at the focus of the zipper.
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Produced by Haddock version 2.7.2 |