Text.XML.Light.Cursor

xml-1.3.14: A simple XML library.

Copyright | (c) Galois Inc. 2008
License | BSD3
Maintainer | Iavor S. Diatchki <diatchki@galois.com>
Stability | provisional
Portability | portable
Safe Haskell | Safe-Inferred
Language | Haskell98

Text.XML.Light.Cursor

Contents

- Conversions
- Moving around
  - Searching
- Node classification
- Updates
  - Inserting content
  - Removing content

Description

XML cursors for working XML content withing the context of an XML document. This implementation is based on the general tree zipper written by Krasimir Angelov and Iavor S. Diatchki.

Synopsis

- data Tag = Tag {
  - tagName :: QName
  - tagAttribs :: [Attr]
  - tagLine :: Maybe Line
  }
- getTag :: Element -> Tag
- setTag :: Tag -> Element -> Element
- fromTag :: Tag -> [Content] -> Element
- data Cursor = Cur {
  - current :: Content
  - lefts :: [Content]
  - rights :: [Content]
  - parents :: Path
  }
- type Path = [([Content], Tag, [Content])]
- fromContent :: Content -> Cursor
- fromElement :: Element -> Cursor
- fromForest :: [Content] -> Maybe Cursor
- toForest :: Cursor -> [Content]
- toTree :: Cursor -> Content
- parent :: Cursor -> Maybe Cursor
- root :: Cursor -> Cursor
- getChild :: Int -> Cursor -> Maybe Cursor
- firstChild :: Cursor -> Maybe Cursor
- lastChild :: Cursor -> Maybe Cursor
- left :: Cursor -> Maybe Cursor
- right :: Cursor -> Maybe Cursor
- nextDF :: Cursor -> Maybe Cursor
- findChild :: (Cursor -> Bool) -> Cursor -> Maybe Cursor
- findLeft :: (Cursor -> Bool) -> Cursor -> Maybe Cursor
- findRight :: (Cursor -> Bool) -> Cursor -> Maybe Cursor
- findRec :: (Cursor -> Bool) -> Cursor -> Maybe Cursor
- isRoot :: Cursor -> Bool
- isFirst :: Cursor -> Bool
- isLast :: Cursor -> Bool
- isLeaf :: Cursor -> Bool
- isChild :: Cursor -> Bool
- hasChildren :: Cursor -> Bool
- getNodeIndex :: Cursor -> Int
- setContent :: Content -> Cursor -> Cursor
- modifyContent :: (Content -> Content) -> Cursor -> Cursor
- modifyContentM :: Monad m => (Content -> m Content) -> Cursor -> m Cursor
- insertLeft :: Content -> Cursor -> Cursor
- insertRight :: Content -> Cursor -> Cursor
- insertGoLeft :: Content -> Cursor -> Cursor
- insertGoRight :: Content -> Cursor -> Cursor
- removeLeft :: Cursor -> Maybe (Content, Cursor)
- removeRight :: Cursor -> Maybe (Content, Cursor)
- removeGoLeft :: Cursor -> Maybe Cursor
- removeGoRight :: Cursor -> Maybe Cursor
- removeGoUp :: Cursor -> Maybe Cursor

# Documentation

data Tag #

Constructors

Tag |
Fields tagName :: QName tagAttribs :: [Attr] tagLine :: Maybe Line

#### Instances

Instances details

Show Tag # |
Instance details Defined in Text.XML.Light.Cursor Methods showsPrec :: Int -> Tag -> ShowS show :: Tag -> String showList :: [Tag] -> ShowS

getTag :: Element -> Tag #

setTag :: Tag -> Element -> Element #

fromTag :: Tag -> [Content] -> Element #

data Cursor #

The position of a piece of content in an XML document.

Constructors

Cur |
Fields current :: Content The currently selected content. lefts :: [Content] Siblings on the left, closest first. rights :: [Content] Siblings on the right, closest first. parents :: Path The contexts of the parent elements of this location.

#### Instances

Instances details

Show Cursor # |
Instance details Defined in Text.XML.Light.Cursor Methods showsPrec :: Int -> Cursor -> ShowS show :: Cursor -> String showList :: [Cursor] -> ShowS

type Path = [([Content], Tag, [Content])] #

# Conversions

fromContent :: Content -> Cursor #

A cursor for the given content.

fromElement :: Element -> Cursor #

A cursor for the given element.

fromForest :: [Content] -> Maybe Cursor #

The location of the first tree in a forest.

toForest :: Cursor -> [Content] #

Computes the forest containing this location.

toTree :: Cursor -> Content #

Computes the tree containing this location.

# Moving around

parent :: Cursor -> Maybe Cursor #

The parent of the given location.

root :: Cursor -> Cursor #

The top-most parent of the given location.

getChild :: Int -> Cursor -> Maybe Cursor #

The child with the given index (starting from 0).

firstChild :: Cursor -> Maybe Cursor #

The first child of the given location.

lastChild :: Cursor -> Maybe Cursor #

The last child of the given location.

left :: Cursor -> Maybe Cursor #

The left sibling of the given location.

right :: Cursor -> Maybe Cursor #

The right sibling of the given location.

nextDF :: Cursor -> Maybe Cursor #

The next position in a left-to-right depth-first traversal of a document: either the first child, right sibling, or the right sibling of a parent that has one.

## Searching

findChild :: (Cursor -> Bool) -> Cursor -> Maybe Cursor #

The first child that satisfies a predicate.

findLeft :: (Cursor -> Bool) -> Cursor -> Maybe Cursor #

Find the next left sibling that satisfies a predicate.

findRight :: (Cursor -> Bool) -> Cursor -> Maybe Cursor #

Find the next right sibling that satisfies a predicate.

findRec :: (Cursor -> Bool) -> Cursor -> Maybe Cursor #

Perform a depth first search for a descendant that satisfies the given predicate.

# Node classification

isRoot :: Cursor -> Bool #

Are we at the top of the document?

isFirst :: Cursor -> Bool #

Are we at the left end of the the document?

isLast :: Cursor -> Bool #

Are we at the right end of the document?

isLeaf :: Cursor -> Bool #

Are we at the bottom of the document?

isChild :: Cursor -> Bool #

Do we have a parent?

hasChildren :: Cursor -> Bool #

Do we have children?

getNodeIndex :: Cursor -> Int #

Get the node index inside the sequence of children

# Updates

setContent :: Content -> Cursor -> Cursor #

Change the current content.

modifyContent :: (Content -> Content) -> Cursor -> Cursor #

Modify the current content.

modifyContentM :: Monad m => (Content -> m Content) -> Cursor -> m Cursor #

Modify the current content, allowing for an effect.

## Inserting content

insertLeft :: Content -> Cursor -> Cursor #

Insert content to the left of the current position.

insertRight :: Content -> Cursor -> Cursor #

Insert content to the right of the current position.

insertGoLeft :: Content -> Cursor -> Cursor #

Insert content to the left of the current position. The new content becomes the current position.

insertGoRight :: Content -> Cursor -> Cursor #

Insert content to the right of the current position. The new content becomes the current position.

## Removing content

removeLeft :: Cursor -> Maybe (Content, Cursor) #

Remove the content on the left of the current position, if any.

removeRight :: Cursor -> Maybe (Content, Cursor) #

Remove the content on the right of the current position, if any.

removeGoLeft :: Cursor -> Maybe Cursor #

Remove the current element. The new position is the one on the left.

removeGoRight :: Cursor -> Maybe Cursor #

Remove the current element. The new position is the one on the right.

removeGoUp :: Cursor -> Maybe Cursor #

Remove the current element. The new position is the parent of the old position.