hexpat-0.18.3: XML parser/formatter based on expat

Text.XML.Expat.Annotated

Contents

Description

A variant of Node in which Element nodes have an annotation of any type, and some concrete functions that annotate with the XML parse location.

The names conflict with those in Tree so you must use qualified import if you want to use both modules.

Synopsis

Tree structure

type Node a tag text = NodeG a [] tag textSource

A pure tree representation that uses a list as its container type, annotated variant.

In the hexpat package, a list of nodes has the type [Node tag text], but note that you can also use the more general type function ListOf to give a list of any node type, using that node's associated list type, e.g. ListOf (UNode Text).

data NodeG a c tag text Source

Annotated variant of the tree representation of the XML document, meaning that it has an extra piece of information of your choice attached to each Element.

c is the container type for the element's children, which is [] in the hexpat package, and a monadic list type for hexpat-iteratee.

tag is the tag type, which can either be one of several string types, or a special type from the Text.XML.Expat.Namespaced or Text.XML.Expat.Qualified modules.

text is the string type for text content.

a is the type of the annotation. One of the things this can be used for is to store the XML parse location, which is useful for error handling.

Note that some functions in the Text.XML.Expat.Cursor module need to create new nodes through the MkElementClass type class. Normally this can only be done if a is a Maybe type (so it can provide the Nothing value for the annotation on newly created nodes). Or, you can write your own MkElementClass instance. Apart from that, there is no requirement for a to be a Maybe type.

Constructors

Element 

Fields

eName :: !tag
 
eAttributes :: ![(tag, text)]
 
eChildren :: c (NodeG a c tag text)
 
eAnn :: a
 
Text !text 

Instances

(Functor c, List c) => MkElementClass (NodeG (Maybe a)) c 
(Functor c, List c) => NodeClass (NodeG a) c 
(Eq tag, Eq text, Eq a) => Eq (NodeG a [] tag text) 
(Show tag, Show text, Show a) => Show (NodeG a [] tag text) 
(NFData tag, NFData text, NFData a) => NFData (NodeG a [] tag text) 

type UNode a text = Node a text textSource

Type alias for a single annotated node with unqualified tag names where tag and text are the same string type

type LNode tag text = Node XMLParseLocation tag textSource

Type alias for a single annotated node, annotated with parse location

type ULNode text = LNode text textSource

Type alias for a single node with unqualified tag names where tag and text are the same string type, annotated with parse location

Generic node manipulation

Annotation-specific

modifyAnnotation :: (a -> a) -> Node a tag text -> Node a tag textSource

Modify this node's annotation (non-recursively) if it's an element, otherwise no-op.

mapAnnotation :: (a -> b) -> Node a tag text -> Node b tag textSource

Modify this node's annotation and all its children recursively if it's an element, otherwise no-op.

Qualified nodes

type QNode a text = Node a (QName text) textSource

Type alias for a single annotated node where qualified names are used for tags

type QLNode text = LNode (QName text) textSource

Type alias for a single node where qualified names are used for tags, annotated with parse location

Namespaced nodes

type NNode a text = Node a (NName text) textSource

Type alias for a single annotated node where namespaced names are used for tags

type NLNode text = LNode (NName text) textSource

Type alias for a single node where namespaced names are used for tags, annotated with parse location

Parse to tree

data ParseOptions tag text Source

Constructors

ParseOptions 

Fields

overrideEncoding :: Maybe Encoding

The encoding parameter, if provided, overrides the document's encoding declaration.

entityDecoder :: Maybe (tag -> Maybe text)

If provided, entity references (i.e.   and friends) will be decoded into text using the supplied lookup function

data Encoding Source

Encoding types available for the document encoding.

Constructors

ASCII 
UTF8 
UTF16 
ISO88591 

parseSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> ParseOptions tag text

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> (LNode tag text, Maybe XMLParseError) 

Lazily parse XML to tree. Note that forcing the XMLParseError return value will force the entire parse. Therefore, to ensure lazy operation, don't check the error status until you have processed the tree.

parse'Source

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> ParseOptions tag text

Optional encoding override

-> ByteString

Input text (a strict ByteString)

-> Either XMLParseError (LNode tag text) 

Strictly parse XML to tree. Returns error message or valid parsed tree.

data XMLParseError Source

Parse error, consisting of message text and error location

data XMLParseLocation Source

Specifies a location of an event within the input text

Constructors

XMLParseLocation 

Fields

xmlLineNumber :: Int64

Line number of the event

xmlColumnNumber :: Int64

Column number of the event

xmlByteIndex :: Int64

Byte index of event from start of document

xmlByteCount :: Int64

The number of bytes in the event

Variant that throws exceptions

parseThrowingSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> ParseOptions tag text

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> LNode tag text 

Lazily parse XML to tree. In the event of an error, throw XMLParseException.

parseThrowing can throw an exception from pure code, which is generally a bad way to handle errors, because Haskell's lazy evaluation means it's hard to predict where it will be thrown from. However, it may be acceptable in situations where it's not expected during normal operation, depending on the design of your program.

data XMLParseException Source

An exception indicating an XML parse error, used by the ..Throwing variants.

SAX-style parse

data SAXEvent tag text Source

Constructors

StartElement tag [(tag, text)] 
EndElement tag 
CharacterData text 
FailDocument XMLParseError 

Instances

(Eq tag, Eq text) => Eq (SAXEvent tag text) 
(Show tag, Show text) => Show (SAXEvent tag text) 
(NFData tag, NFData text) => NFData (SAXEvent tag text) 

saxToTree :: GenericXMLString tag => [(SAXEvent tag text, a)] -> (Node a tag text, Maybe XMLParseError)Source

A lower level function that lazily converts a SAX stream into a tree structure. Variant that takes annotations for start tags.

Abstraction of string types

class (Monoid s, Eq s) => GenericXMLString s whereSource

An abstraction for any string type you want to use as xml text (that is, attribute values or element text content). If you want to use a new string type with hexpat, you must make it an instance of GenericXMLString.

Deprecated

eAttrs :: Node a tag text -> [(tag, text)]Source

parseSAXSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> [SAXEvent tag text] 

DEPRECATED: Use parse instead.

Lazily parse XML to SAX events. In the event of an error, FailDocument is the last element of the output list. Deprecated in favour of new parse

parseSAXThrowingSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> [SAXEvent tag text] 

DEPRECATED: Use parseThrowing instead.

Lazily parse XML to SAX events. In the event of an error, throw XMLParseException.

parseSAXLocationsSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> [(SAXEvent tag text, XMLParseLocation)] 

DEPRECATED: Use parseLocations instead.

A variant of parseSAX that gives a document location with each SAX event.

parseSAXLocationsThrowingSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> [(SAXEvent tag text, XMLParseLocation)] 

DEPRECATED: Used parseLocationsThrowing instead.

A variant of parseSAX that gives a document location with each SAX event. In the event of an error, throw XMLParseException.

parseTreeSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> (LNode tag text, Maybe XMLParseError) 

DEPRECATED: Use parse instead.

Lazily parse XML to tree. Note that forcing the XMLParseError return value will force the entire parse. Therefore, to ensure lazy operation, don't check the error status until you have processed the tree.

parseTree'Source

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a strict ByteString)

-> Either XMLParseError (LNode tag text) 

DEPRECATED: use parse instead.

Strictly parse XML to tree. Returns error message or valid parsed tree.

parseTreeThrowingSource

Arguments

:: (GenericXMLString tag, GenericXMLString text) 
=> Maybe Encoding

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> LNode tag text 

DEPRECATED: use parseThrowing instead

Lazily parse XML to tree. In the event of an error, throw XMLParseException.

unannotate :: Functor c => NodeG a c tag text -> NodeG c tag textSource

Convert an annotated tree (Annotated module) into a non-annotated tree (Tree module). DEPRECATED in favour of fromElement.

type ParserOptions tag text = ParseOptions tag textSource

defaultParserOptions :: ParseOptions tag textSource

DEPRECATED. Renamed to defaultParseOptions.