net.sf.saxon.query
Class QueryParser

java.lang.Object
  net.sf.saxon.expr.ExpressionParser
      net.sf.saxon.query.QueryParser

public class QueryParser
extends ExpressionParser

This class defines extensions to the XPath parser to handle the additional syntax supported in XQuery

Nested Class Summary

Nested classes/interfaces inherited from class net.sf.saxon.expr.ExpressionParser

ExpressionParser.ForClause

Field Summary

Fields inherited from class net.sf.saxon.expr.ExpressionParser

env, numberOfRangeVariables, rangeVariables, scanOnly, t

Constructor Summary

QueryParser()

Method Summary

protected String	getLanguage() Get the current language (XPath or XQuery)
protected void	grumble(String message) Report a parsing error
protected StringValue	makeStringLiteral(String token) Method to make a string literal from a token identified as a string literal.
protected Expression	parseConstructor() Parse a node constructor.
protected Expression	parseForExpression() Parse a FLWOR expression.
void	parseLibraryModule(String queryString, StaticQueryContext env) Parse a library module.
Expression	parseQuery(String queryString, int start, int terminator, StaticQueryContext env) Parse a top-level Query.
protected Expression	parseTypeswitchExpression() Parse a Typeswitch Expression.
protected Expression	parseValidateExpression() Parse a Validate Expression.
ValidationContext	parseValidationContext() Parse a validation context.

Methods inherited from class net.sf.saxon.expr.ExpressionParser

currentTokenDisplay, declareRangeVariable, expect, getRangeVariableStack, getTokenizer, isKeyword, makeLocalNameTest, makeLocator, makeNameCode, makeNamespaceTest, makeNameTest, nextToken, parse, parseExpression, parseExprSingle, parseMappingExpression, parseNodeTest, parsePattern, parseRelativePath, parseSequenceType, parseSequenceType, parseStepExpression, setLocation, setLocation, setRangeVariableStack, setScanOnly, undeclareRangeVariable, warning

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QueryParser

public QueryParser()

Method Detail

parseQuery

public final Expression parseQuery(String queryString,
                                   int start,
                                   int terminator,
                                   StaticQueryContext env)
                            throws XPathException

Parse a top-level Query. Prolog? Expression

Parameters:

queryString - The text of the query

start - Offset of the start of the query

terminator - Token expected to follow the query (usually Tokenizer.EOF)

env - The static context

Returns:

the Expression object that results from parsing

Throws:

XPathException - if the expression contains a syntax error

parseLibraryModule

public final void parseLibraryModule(String queryString,
                                     StaticQueryContext env)
                              throws XPathException

Parse a library module. Prolog? Expression

Parameters:

queryString - The text of the library module.

env - The static context. The result of parsing a library module is that the static context is populated with a set of function declarations and variable declarations. Each library module must have its own static context objext.

Throws:

XPathException - if the expression contains a syntax error

grumble

protected void grumble(String message)
                throws XPathException

Report a parsing error

Overrides:

grumble in class ExpressionParser

Parameters:

message - the error message

Throws:

XPathException - always thrown: an exception containing the supplied message

parseForExpression

protected Expression parseForExpression()
                                 throws XPathException

Parse a FLWOR expression. This replaces the XPath "for" expression. Full syntax:

[41] FLWORExpr ::= (ForClause | LetClause)+ WhereClause? OrderByClause? "return" ExprSingle [42] ForClause ::= <"for" "$"> VarName TypeDeclaration? PositionalVar? "in" ExprSingle ("," "$" VarName TypeDeclaration? PositionalVar? "in" ExprSingle)* [43] PositionalVar ::= "at" "$" VarName [44] LetClause ::= <"let" "$"> VarName TypeDeclaration? ":=" ExprSingle ("," "$" VarName TypeDeclaration? ":=" ExprSingle)* [45] WhereClause ::= "where" Expr [46] OrderByClause ::= (<"order" "by"> | <"stable" "order" "by">) OrderSpecList [47] OrderSpecList ::= OrderSpec ("," OrderSpec)* [48] OrderSpec ::= ExprSingle OrderModifier [49] OrderModifier ::= ("ascending" | "descending")? (<"empty" "greatest"> | <"empty" "least">)? ("collation" StringLiteral)?

Overrides:

parseForExpression in class ExpressionParser

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parseTypeswitchExpression

protected Expression parseTypeswitchExpression()
                                        throws XPathException

Parse a Typeswitch Expression. This construct is XQuery-only. TypeswitchExpr ::= "typeswitch" "(" Expr ")" CaseClause+ "default" ("$" VarName)? "return" ExprSingle CaseClause ::= "case" ("$" VarName "as")? SequenceType "return" Expr

Overrides:

parseTypeswitchExpression in class ExpressionParser

Throws:

XPathException

parseValidateExpression

protected Expression parseValidateExpression()
                                      throws XPathException

Parse a Validate Expression. This construct is XQuery-only. The syntax allows: validate mode? context? { Expr } mode ::= "strict" | "lax" | "skip" context ::= "global" | "context" schemaContext

Overrides:

parseValidateExpression in class ExpressionParser

Throws:

XPathException

parseValidationContext

public ValidationContext parseValidationContext()
                                         throws XPathException

Parse a validation context. Syntax ( qname | type(qname) ) ( '/' qname )*

Throws:

XPathException

parseConstructor

protected Expression parseConstructor()
                               throws XPathException

Parse a node constructor. This is allowed only in XQuery. This method handles both the XML-like "direct" constructors, and the XQuery-based "computed" constructors.

Overrides:

parseConstructor in class ExpressionParser

Returns:

an Expression for evaluating the parsed constructor

Throws:

XPathException - in the event of a syntax error.

makeStringLiteral

protected StringValue makeStringLiteral(String token)
                                 throws XPathException

Method to make a string literal from a token identified as a string literal. This is trivial in XPath, but in XQuery the method is overridden to identify pseudo-XML character and entity references

Overrides:

makeStringLiteral in class ExpressionParser

Parameters:

token -

Returns:

The string value of the string literal, after dereferencing entity and character references

Throws:

XPathException

getLanguage

protected String getLanguage()

Get the current language (XPath or XQuery)

Overrides:

getLanguage in class ExpressionParser