net.sf.saxon.query
Class QueryParser

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

Direct Known Subclasses:

UpdateParser

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, ExpressionParser.TemporaryContainer

Field Summary

protected Executable	executable
java.util.Set	importedModules

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

compileWithTracing, env, language, nameChecker, rangeVariables, scanOnly, SEQUENCE_TYPE, t, XPATH, XQUERY, XSLT_PATTERN

Constructor Summary

QueryParser()
Constructor for internal use: this class should be instantiated via the QueryModule

Method Summary

void	applyModuleImport(net.sf.saxon.query.QueryParser.Import mImport)
Executable	getExecutable() Get the executable containing this expression.
protected java.lang.String	getLanguage() Get the current language (XPath or XQuery)
protected void	grumble(java.lang.String message, java.lang.String errorCode) Report a static error
static Expression	makeStringJoin(Expression exp, StaticContext env) Make a string-join expression that concatenates the string-values of items in a sequence with intervening spaces.
protected Literal	makeStringLiteral(java.lang.String token) Method to make a string literal from a token identified as a string literal.
XQueryExpression	makeXQueryExpression(java.lang.String query, QueryModule staticContext, Configuration config) Create an XQueryExpression
protected Expression	parseConstructor() Parse a node constructor.
protected Expression	parseExtensionExpression() Parse an Extension Expression.
protected Expression	parseForExpression() Parse a FLWOR expression.
protected void	parseFunctionDeclaration(boolean isUpdating) Parse a function declaration.
void	parseLibraryModule(java.lang.String queryString, QueryModule env) Parse a library module.
protected void	parseRevalidationDeclaration() Parse the "declare revalidation" declaration.
protected Expression	parseTypeswitchExpression() Parse a Typeswitch Expression.
protected void	parseUpdatingFunctionDeclaration() Parse an updating function declaration (allowed in XQuery Update only)
protected Expression	parseValidateExpression() Parse a Validate Expression.
Expression	setDefaultValue(java.lang.String exp) Parse the expression (inside a string literal) used to define default values for external variables.
void	setDisableCycleChecks(boolean disable) Disable checks for certain kinds of cycle.
void	setExecutable(Executable exec) Set the executable used for this query expression

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

currentTokenDisplay, declareRangeVariable, expect, getRangeVariableStack, getTokenizer, grumble, isCompileWithTracing, isKeyword, makeLocalNameTest, makeNameCode, makeNameCodeSilently, makeNamespaceTest, makeNameTest, makeStructuredQName, makeTracer, nextToken, parse, parseExpression, parseExprSingle, parseFunctionCall, parseMappingExpression, parseNodeTest, parsePattern, parseRelativePath, parseRemainingPath, parseSequenceType, parseSequenceType, parseStepExpression, setCompileWithTracing, setLocation, setLocation, setRangeVariableStack, setScanOnly, undeclareRangeVariable, warning

Methods inherited from class java.lang.Object

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

Field Detail

executable

protected Executable executable

importedModules

public java.util.Set importedModules

Constructor Detail

QueryParser

public QueryParser()

Constructor for internal use: this class should be instantiated via the QueryModule

Method Detail

makeXQueryExpression

public XQueryExpression makeXQueryExpression(java.lang.String query,
                                             QueryModule staticContext,
                                             Configuration config)
                                      throws XPathException

Create an XQueryExpression

Parameters:

query - the source text of the query

staticContext - the static context of the query

config - the Saxon configuration

Returns:

the compiled XQuery expression

Throws:

XPathException

getExecutable

public Executable getExecutable()

Get the executable containing this expression.

Returns:

the executable

setExecutable

public void setExecutable(Executable exec)

Set the executable used for this query expression

Parameters:

exec - the executable

setDisableCycleChecks

public void setDisableCycleChecks(boolean disable)

Disable checks for certain kinds of cycle. This is equivalent to

declare option saxon:allow-cycles "true"

Parameters:

disable - true if checks for import cycles are to be suppressed, that is, if cycles should be allowed

parseLibraryModule

public final void parseLibraryModule(java.lang.String queryString,
                                     QueryModule 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(java.lang.String message,
                       java.lang.String errorCode)
                throws XPathException

Report a static error

Overrides:

grumble in class ExpressionParser

Parameters:

message - the error message

errorCode - the error code

Throws:

XPathException - always thrown: an exception containing the supplied message

parseRevalidationDeclaration

protected void parseRevalidationDeclaration()
                                     throws XPathException

Parse the "declare revalidation" declaration. Syntax: not allowed unless XQuery update is in use

Throws:

XPathException

applyModuleImport

public void applyModuleImport(net.sf.saxon.query.QueryParser.Import mImport)
                       throws XPathException

Throws:

XPathException

parseFunctionDeclaration

protected void parseFunctionDeclaration(boolean isUpdating)
                                 throws XPathException

Parse a function declaration.

Syntax:
<"declare" "function"> ParamList? (")" | (<")" "as"> SequenceType)) (EnclosedExpr | "external")

On entry, the "define function" has already been recognized

Throws:

XPathException - if a syntax error is found

parseUpdatingFunctionDeclaration

protected void parseUpdatingFunctionDeclaration()
                                         throws XPathException

Parse an updating function declaration (allowed in XQuery Update only)

Throws:

XPathException

setDefaultValue

public Expression setDefaultValue(java.lang.String exp)

Parse the expression (inside a string literal) used to define default values for external variables. This requires instantiating a nested XPath parser.

Parameters:

exp - holds the expression used to define a default value

Returns:

the compiled expression that computes the default value

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

makeStringJoin

public static Expression makeStringJoin(Expression exp,
                                        StaticContext env)

Make a string-join expression that concatenates the string-values of items in a sequence with intervening spaces. This may be simplified later as a result of type-checking.

Parameters:

exp - the base expression, evaluating to a sequence

env - the static context

Returns:

a call on string-join to create a string containing the representations of the items in the sequence separated by spaces.

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" ExprSingle

Overrides:

parseTypeswitchExpression in class ExpressionParser

Returns:

the expression that results from the parsing

Throws:

XPathException

parseValidateExpression

protected Expression parseValidateExpression()
                                      throws XPathException

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

Overrides:

parseValidateExpression in class ExpressionParser

Returns:

the parsed expression; except that this version of the method always throws an exception

Throws:

XPathException

parseExtensionExpression

protected Expression parseExtensionExpression()
                                       throws XPathException

Parse an Extension Expression. Syntax: "(#" QName arbitrary-text "#)")+ "{" expr? "}"

Overrides:

parseExtensionExpression in class ExpressionParser

Returns:

the parsed expression; except that this version of the method always throws an exception

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 Literal makeStringLiteral(java.lang.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 - the string as written (or as returned by the tokenizer)

Returns:

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

Throws:

XPathException

getLanguage

protected java.lang.String getLanguage()

Get the current language (XPath or XQuery)

Overrides:

getLanguage in class ExpressionParser

Returns:

a string representation of the language being parsed, for use in error messages