Safe Haskell	Safe-Inferred
Language	Haskell2010

Generics.Diff.Special.Tree

Contents

Description

A worked example of implementing SpecialDiff (and thereby Diff) for Trees.

As with other 3rd-party types, there are different approaches we can take here. We'll show 2 of them:

Synopsis

Documentation

A newtype wrapper around Tree to demonstrate one alternate way we could hand-write a SpecialDiff instance.

Constructors

Instances details

Show a => Show (CustomTree a) Source #
Instance details Defined in Generics.Diff.Special.Tree Methods showsPrec :: Int -> CustomTree a -> ShowS # show :: CustomTree a -> String # showList :: [CustomTree a] -> ShowS #
Diff a => Diff (CustomTree a) Source #
Instance details Defined in Generics.Diff.Special.Tree Methods diff :: CustomTree a -> CustomTree a -> DiffResult (CustomTree a) # diffList :: [CustomTree a] -> [CustomTree a] -> DiffResult [CustomTree a] #
Diff a => SpecialDiff (CustomTree a) Source #
Instance details Defined in Generics.Diff.Special.Tree Associated Types type SpecialDiffError (CustomTree a) # Methods specialDiff :: CustomTree a -> CustomTree a -> Maybe (SpecialDiffError (CustomTree a)) # renderSpecialDiffError :: SpecialDiffError (CustomTree a) -> Doc #
type SpecialDiffError (CustomTree a) Source #
Instance details Defined in Generics.Diff.Special.Tree type SpecialDiffError (CustomTree a) = CustomTreeDiffError a

Where are we in the tree? Each element of the list says which child node we step to next.

Constructors

Instances details

Show TreePath Source #
Instance details Defined in Generics.Diff.Special.Tree Methods showsPrec :: Int -> TreePath -> ShowS # show :: TreePath -> String # showList :: [TreePath] -> ShowS #
Eq TreePath Source #
Instance details Defined in Generics.Diff.Special.Tree Methods (==) :: TreePath -> TreePath -> Bool # (/=) :: TreePath -> TreePath -> Bool #

A custom error type for CustomTree.

Constructors

DiffAtNode TreePath (DiffError a)
WrongLengthsOfChildren TreePath Int Int

Instances details

Show (CustomTreeDiffError a) Source #
Instance details Defined in Generics.Diff.Special.Tree Methods showsPrec :: Int -> CustomTreeDiffError a -> ShowS # show :: CustomTreeDiffError a -> String # showList :: [CustomTreeDiffError a] -> ShowS #
Eq (CustomTreeDiffError a) Source #
Instance details Defined in Generics.Diff.Special.Tree Methods (==) :: CustomTreeDiffError a -> CustomTreeDiffError a -> Bool # (/=) :: CustomTreeDiffError a -> CustomTreeDiffError a -> Bool #

Render a tree path as a Builder

Orphan instances

Diff a => Diff (Tree a) Source #
Instance details Methods diff :: Tree a -> Tree a -> DiffResult (Tree a) # diffList :: [Tree a] -> [Tree a] -> DiffResult [Tree a] #
Diff a => SpecialDiff (Tree a) Source #	Generically-derived instance.
Instance details Associated Types type SpecialDiffError (Tree a) # Methods specialDiff :: Tree a -> Tree a -> Maybe (SpecialDiffError (Tree a)) # renderSpecialDiffError :: SpecialDiffError (Tree a) -> Doc #