Text.XML.Expat.SAX

This module provides functions to parse an XML document to a lazy stream of SAX events.

XML primitives

data Encoding

Constructors

ASCII

UTF8

UTF16

ISO88591

data XMLParseError

Parse error, consisting of message text and error location

Constructors

XMLParseError String XMLParseLocation

Instances

Eq XMLParseError

Methods

(==) :: XMLParseError -> XMLParseError -> Bool

(/=) :: XMLParseError -> XMLParseError -> Bool

Show XMLParseError

Methods

showsPrec :: Int -> XMLParseError -> ShowS

show :: XMLParseError -> String

showList :: [XMLParseError] -> ShowS

NFData XMLParseError

Methods

rnf :: XMLParseError -> ()

data XMLParseLocation

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

Instances

Eq XMLParseLocation

Methods

(==) :: XMLParseLocation -> XMLParseLocation -> Bool

(/=) :: XMLParseLocation -> XMLParseLocation -> Bool

Show XMLParseLocation

Methods

showsPrec :: Int -> XMLParseLocation -> ShowS

show :: XMLParseLocation -> String

showList :: [XMLParseLocation] -> ShowS

NFData XMLParseLocation

Methods

rnf :: XMLParseLocation -> ()

SAX-style parse

data ParseOptions tag text

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 SAXEvent tag text

Constructors

XMLDeclaration text (Maybe text) (Maybe Bool)

StartElement tag [(tag, text)]

EndElement tag

CharacterData text

StartCData

EndCData

ProcessingInstruction text text

Comment text

FailDocument XMLParseError

Instances

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

Methods

(==) :: SAXEvent tag text -> SAXEvent tag text -> Bool

(/=) :: SAXEvent tag text -> SAXEvent tag text -> Bool

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

Methods

showsPrec :: Int -> SAXEvent tag text -> ShowS

show :: SAXEvent tag text -> String

showList :: [SAXEvent tag text] -> ShowS

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

Methods

rnf :: SAXEvent tag text -> ()

parse

Arguments

:: (GenericXMLString tag, GenericXMLString text)

=> ParseOptions tag text

Parse options

-> ByteString

Input text (a lazy ByteString)

-> [SAXEvent tag text]

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

parseG

Arguments

:: (GenericXMLString tag, GenericXMLString text, List l)

=> ParseOptions tag text

Parse options

-> l ByteString

Input text (a lazy ByteString)

-> l (SAXEvent tag text)

Parse a generalized list of ByteStrings containing XML to SAX events. In the event of an error, FailDocument is the last element of the output list.

parseLocations

Arguments

:: (GenericXMLString tag, GenericXMLString text)

=> ParseOptions tag text

Parse options

-> ByteString

Input text (a lazy ByteString)

-> [(SAXEvent tag text, XMLParseLocation)]

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

parseLocationsG

Arguments

:: (GenericXMLString tag, GenericXMLString text, List l)

=> ParseOptions tag text

Parse options

-> l ByteString

Input text (a lazy ByteString)

-> l (SAXEvent tag text, XMLParseLocation)

Parse a generalized list of ByteStrings containing XML to SAX events. In the event of an error, FailDocument is the last element of the output list.

parseLocationsThrowing

Arguments

:: (GenericXMLString tag, GenericXMLString text)

=> ParseOptions tag text

Optional encoding override

-> ByteString

Input text (a lazy ByteString)

-> [(SAXEvent tag text, XMLParseLocation)]

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

parseLocationsThrowing 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.

parseThrowing

Arguments

:: (GenericXMLString tag, GenericXMLString text)

=> ParseOptions tag text

Parse options

-> ByteString

input text (a lazy ByteString)

-> [SAXEvent tag text]

Lazily parse XML to SAX events. 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.

defaultParseOptions :: ParseOptions tag text

Variants that throw exceptions

data XMLParseException

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

Constructors

XMLParseException XMLParseError

Instances

Eq XMLParseException

Methods

(==) :: XMLParseException -> XMLParseException -> Bool

(/=) :: XMLParseException -> XMLParseException -> Bool

Show XMLParseException

Methods

showsPrec :: Int -> XMLParseException -> ShowS

show :: XMLParseException -> String

showList :: [XMLParseException] -> ShowS

Exception XMLParseException

Methods

toException :: XMLParseException -> SomeException

fromException :: SomeException -> Maybe XMLParseException

displayException :: XMLParseException -> String

Abstraction of string types

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

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.

Minimal complete definition

gxNullString, gxToString, gxFromString, gxFromChar, gxHead, gxTail, gxBreakOn, gxFromByteString, gxToByteString

Methods

gxNullString :: s -> Bool

gxToString :: s -> String

gxFromString :: String -> s

gxFromChar :: Char -> s

gxHead :: s -> Char

gxTail :: s -> s

gxBreakOn :: Char -> s -> (s, s)

gxFromByteString :: ByteString -> s

gxToByteString :: s -> ByteString

Instances

GenericXMLString String

Methods

gxNullString :: String -> Bool

gxToString :: String -> String

gxFromString :: String -> String

gxFromChar :: Char -> String

gxHead :: String -> Char

gxTail :: String -> String

gxBreakOn :: Char -> String -> (String, String)

gxFromByteString :: ByteString -> String

gxToByteString :: String -> ByteString

GenericXMLString ByteString

Methods

gxNullString :: ByteString -> Bool

gxToString :: ByteString -> String

gxFromString :: String -> ByteString

gxFromChar :: Char -> ByteString

gxHead :: ByteString -> Char

gxTail :: ByteString -> ByteString

gxBreakOn :: Char -> ByteString -> (ByteString, ByteString)

gxFromByteString :: ByteString -> ByteString

gxToByteString :: ByteString -> ByteString

GenericXMLString Text

Methods

gxNullString :: Text -> Bool

gxToString :: Text -> String

gxFromString :: String -> Text

gxFromChar :: Char -> Text

gxHead :: Text -> Char

gxTail :: Text -> Text

gxBreakOn :: Char -> Text -> (Text, Text)

gxFromByteString :: ByteString -> Text

gxToByteString :: Text -> ByteString