Text.XML.HXQ.XQuery

HXQ is a fast and space-efficient compiler from XQuery (the standard query language for XML) to embedded Haskell code. The translation is based on Haskell templates. It also provides an interpreter for evaluating ad-hoc XQueries read from input or from files and optional database connectivity using HDBC. For more information, look at http://lambda.uta.edu/HXQ/.

The XML Data Representation

data XTree

A rose tree representation of XML data. An XML element is: XElem tagname atributes preorder parent children. The preorder numbering is the document order of elements. The parent is a cyclic reference to the parent element.

Constructors

XElem !Tag !AttList !Int XTree [XTree]

an XML tree node (element)

XText !String

an XML tree leaf (PCDATA)

XInt !Int

an XML tree leaf (int)

XFloat !Float

an XML tree leaf (float)

XBool !Bool

an XML tree leaf (boolean)

XPI Tag String

processing instruction

XGERef Tag

general entity reference

XComment String

comment

XError String

error report

XNull

null value

XNoPad

marker for no padding in XSeq

Instances

Eq XTree

Show XTree

type XSeq = [XTree]

type Tag = String

type AttList = [(Name, String)]

putXSeq :: XSeq -> IO ()

Print the XQuery result (which is a sequence of XML fragments) without buffering.

The XQuery Compiler

xq :: String -> Q Exp

Run an XQuery that may read XML documents. When evaluated, it returns IO XSeq.

xe :: String -> Q Exp

Run an XQuery expression that does not perform IO. When evaluated, it returns XSeq.

The XQuery Interpreter

xquery :: String -> IO XSeq

Evaluate the XQuery using the interpreter.

xfile :: String -> IO XSeq

Read an XQuery from a file and run it using the interpreter.

The XQuery Compiler with Database Connectivity

xqdb :: String -> Q Exp

Run an XQuery that reads XML documents and queries databases. When evaluated, it returns (IConnection conn) => conn -> IO XSeq.

The XQuery Interpreter with Database Connectivity

xqueryDB :: String -> Connection -> IO XSeq

Evaluate the XQuery with database connectivity using the interpreter.

xfileDB :: String -> Connection -> IO XSeq

Read an XQuery with database connectivity from a file and run it using the interpreter.

Shredding and Publishing XML Documents Using a Relational Database

genSchema :: Connection -> String -> String -> IO Table

Create a schema for an XML document into the database under the given name.

shred :: Connection -> String -> String -> IO ()

Store an XML document into the database under the given name.

shredC :: String -> String -> String -> Q Exp

Store an XML document into the database under the given name. Generates Haskell code.

printSchema :: Connection -> String -> IO ()

Print the relational schema of the XML document stored in the database under the given name

createIndex :: Connection -> String -> String -> IO ()

Create a secondary index on tagname for the shredded document under the given name..

Other Functions

data XMLEvent

Constructors

StartEvent Name [(Name, String)]

EmptyEvent Name [(Name, String)]

EndEvent Name

TextEvent String

PIEvent Name String

GERefEvent Name

CommentEvent String

ErrorEvent String

Instances

Read XMLEvent

Show XMLEvent

connect :: FilePath -> IO Connection

Connect to the relational database in filepath

disconnect :: conn -> IO ()

commit :: conn -> IO ()

rollback :: conn -> IO ()

prepareSQL :: Connection -> String -> IO Statement

executeSQL :: Statement -> XSeq -> IO XSeq