net.sf.saxon.expr
Class ExpressionParser

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

Direct Known Subclasses:

PatternParser, QueryParser, SelectionParser, XPath30Parser

public class ExpressionParser
extends Object

Parser for XPath expressions and XSLT patterns. This code was originally inspired by James Clark's xt but has been totally rewritten (several times) The base class handles parsing of XPath 2.0 and XPath 3.0 syntax (switched by a languageVersion variable). Subclasses refine this to handle XQuery syntax (1.0 and 3.0) and XQuery Update syntax.

Author:

Michael Kay

Nested Class Summary

static interface	ExpressionParser.FLWORClause
static class	ExpressionParser.ForClause
protected static class	ExpressionParser.TemporaryContainer

Field Summary

protected boolean	allowXPath30Syntax
protected boolean	compileWithTracing
protected Container	defaultContainer
protected StaticContext	env
protected int	language
protected DecimalValue	languageVersion
protected NameChecker	nameChecker
protected Stack<Binding>	rangeVariables
protected boolean	scanOnly
static int	SEQUENCE_TYPE
protected Tokenizer	t
static int	XPATH
static int	XQUERY
static int	XSLT_PATTERN

Constructor Summary

ExpressionParser()
Create an expression parser

Method Summary

protected boolean	atStartOfRelativePath() Test whether the current token is one that can start a RelativePathExpression
protected String	currentTokenDisplay() Display the current token in an error message
void	declareRangeVariable(Binding declaration) Declare a range variable (record its existence within the parser).
protected boolean	disallowedAtStartOfRelativePath() Test whether the current token is one that is disallowed after a "leading lone slash".
void	expect(int token) Expect a given token; fail if the current token is different.
protected Binding	findRangeVariable(StructuredQName qName) Locate a range variable with a given name.
Container	getDefaultContainer() Get the default container for newly constructed expressions
protected String	getLanguage() Get the current language (XPath or XQuery)
NameChecker	getNameChecker() Get the name checker used by this parser
Stack<Binding>	getRangeVariables() Get the stack of in-scope range variables
StaticContext	getStaticContext() Get the static context used by this expression parser
Tokenizer	getTokenizer() Get the tokenizer (the lexical analyzer)
void	grumble(String message) Report a syntax error (a static error with error code XP0003)
void	grumble(String message, String errorCode) Report a static error
void	grumble(String message, String errorCode, int offset) Report a static error, with location information
protected void	grumble(String message, StructuredQName errorCode, int offset) Report a static error
boolean	isCompileWithTracing() Determine whether trace hooks are included in the compiled code.
protected boolean	isKeyword(String s) Test whether the current token is a given keyword.
protected boolean	isNamespaceTestAllowed() Ask whether the syntax namespace-node() is allowed in a node kind test.
protected Expression	makeCurriedFunction(FunctionCall fcall, Expression[] args, IntSet placeMarkers) Process a function call in which one or more of the argument positions are represented as "?" placemarkers (indicating partial application or currying)
LocalNameTest	makeLocalNameTest(short nodeType, String localName) Make a LocalNameTest (*:name)
int	makeNameCode(String qname, boolean useDefault) Make a NameCode, using the static context for namespace resolution
int	makeNameCodeSilently(String qname, boolean useDefault) Make a NameCode, using the static context for namespace resolution.
NamespaceTest	makeNamespaceTest(short nodeType, String prefix) Make a NamespaceTest (name:*)
NameTest	makeNameTest(short nodeType, String qname, boolean useDefault) Make a NameTest, using the static context for namespace resolution
protected Literal	makeStringLiteral(String currentTokenValue) Method to make a string literal from a token identified as a string literal.
StructuredQName	makeStructuredQName(String qname, boolean useDefault) Make a Structured QName, using the static context for namespace resolution
Expression	makeTracer(int startOffset, Expression exp, int construct, StructuredQName qName) If tracing, wrap an expression in a trace instruction
void	nextToken() Read the next token, catching any exception thrown by the tokenizer
protected String	normalizeEQName(String s) Normalize an EQName.
Expression	parse(String expression, int start, int terminator, int lineNumber, StaticContext env) Parse a string representing an expression.
protected Expression	parseBasicStep(boolean firstInPattern) Parse a basic step expression (without the predicates)
protected Expression	parseConstructor() Parse a node constructor.
protected Expression	parseDynamicFunctionCall(Expression functionItem) Parse a dynamic function call
Expression	parseExpression() Parse a top-level Expression: ExprSingle ( ',' ExprSingle )*
Expression	parseExprSingle() Parse an ExprSingle
protected Expression	parseExtensionExpression() Parse an Extension Expression This construct is XQuery-only, so the XPath version of this method throws an error unconditionally
protected Expression	parseForExpression() Parse a FOR expression: for $x in expr (',' $y in expr)* 'return' expr
protected Expression	parseFunctionArgument() Parse an argument to a function call.
protected Expression	parseFunctionCall() Parse a function call.
protected ItemType	parseFunctionItemType() Get the item type used for function items (XQuery 1.1 higher order functions)
protected Expression	parseInlineFunction() Parse an inline function "function" "(" ParamList? ")" ("as" SequenceType)? EnclosedExpr On entry, "function (" has already been read
protected ItemType	parseItemType() Parse an ItemType within a SequenceType
protected Expression	parseLiteralFunctionItem() Parse a literal function item (introduced in XQuery 1.1) Syntax: QName # integer The QName and # have already been read
protected NodeTest	parseNodeTest(short nodeType) Parse a NodeTest.
protected Expression	parseNumericLiteral()
protected ItemType	parseParenthesizedItemType() Parse a parenthesized item type (allowed in XQuery 1.1 only)
protected Expression	parsePathExpression() Parse a PathExpresssion.
protected Expression	parsePredicate() Parse the expression within a predicate.
protected Expression	parseRelativePath() Parse a relative path (a sequence of steps).
protected Expression	parseRemainingPath(Expression start) Parse the remaining steps of an absolute path expression (one starting in "/" or "//").
SequenceType	parseSequenceType() Parse the sequence type production.
SequenceType	parseSequenceType(String input, StaticContext env) Parse a string representing a sequence type
protected Expression	parseStepExpression(boolean firstInPattern) Parse a step (including an optional sequence of predicates)
protected Expression	parseStringLiteral()
protected Expression	parseSwitchExpression() Parse a Switch Expression.
protected Expression	parseTryCatchExpression() Parse a try/catch Expression This construct is XQuery-1.1 only, so the XPath version of this method throws an error unconditionally
protected Expression	parseTypeswitchExpression() Parse a Typeswitch Expression.
protected Expression	parseUnionExpression() Parse a UnionExpr: IntersectExceptExpr ( "|" | "union" IntersectExceptExpr )*
protected Expression	parseValidateExpression() Parse a Validate Expression.
protected Expression	parseVariableReference()
protected StructuredQName	resolveFunctionName(String fname)
void	setCompileWithTracing(boolean trueOrFalse) Set whether trace hooks are to be included in the compiled code.
void	setDefaultContainer(Container container) Set the default container for newly constructed expressions
void	setLanguage(int language, DecimalValue version) Set the current language (XPath or XQuery, XSLT Pattern, or SequenceType)
protected void	setLocation(Expression exp) Set location information on an expression.
void	setLocation(Expression exp, int offset) Set location information on an expression.
void	setRangeVariables(Stack<Binding> variables) Set a new stack of in-scope range variables
void	setRangeVariableStack(Stack<Binding> stack) Set the range variable stack.
void	setScanOnly(boolean scanOnly) Set that we are parsing in "scan only"
void	undeclareRangeVariable() Note when the most recently declared range variable has gone out of scope
protected void	warning(String message) Output a warning message

Methods inherited from class java.lang.Object

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

Field Detail

t

protected Tokenizer t

env

protected StaticContext env

rangeVariables

protected Stack<Binding> rangeVariables

defaultContainer

protected Container defaultContainer

nameChecker

protected NameChecker nameChecker

allowXPath30Syntax

protected boolean allowXPath30Syntax

scanOnly

protected boolean scanOnly

compileWithTracing

protected boolean compileWithTracing

language

protected int language

XPATH

public static final int XPATH

See Also:

Constant Field Values

XSLT_PATTERN

public static final int XSLT_PATTERN

See Also:

Constant Field Values

SEQUENCE_TYPE

public static final int SEQUENCE_TYPE

See Also:

Constant Field Values

XQUERY

public static final int XQUERY

See Also:

Constant Field Values

languageVersion

protected DecimalValue languageVersion

Constructor Detail

ExpressionParser

public ExpressionParser()

Create an expression parser

Method Detail

setCompileWithTracing

public void setCompileWithTracing(boolean trueOrFalse)

Set whether trace hooks are to be included in the compiled code. To use tracing, it is necessary both to compile the code with trace hooks included, and to supply a TraceListener at run-time

Parameters:

trueOrFalse - true if trace code is to be compiled in, false otherwise

isCompileWithTracing

public boolean isCompileWithTracing()

Determine whether trace hooks are included in the compiled code.

Returns:

true if trace hooks are included, false if not.

getTokenizer

public Tokenizer getTokenizer()

Get the tokenizer (the lexical analyzer)

Returns:

the tokenizer (the lexical analyzer)

getStaticContext

public StaticContext getStaticContext()

Get the static context used by this expression parser

Returns:

the static context

setDefaultContainer

public void setDefaultContainer(Container container)

Set the default container for newly constructed expressions

Parameters:

container - the default container

getDefaultContainer

public Container getDefaultContainer()

Get the default container for newly constructed expressions

Returns:

the default container

getNameChecker

public NameChecker getNameChecker()

Get the name checker used by this parser

Returns:

the name checker (specific to XML 1.0o

nextToken

public void nextToken()
               throws XPathException

Read the next token, catching any exception thrown by the tokenizer

Throws:

XPathException

expect

public void expect(int token)
            throws XPathException

Expect a given token; fail if the current token is different. Note that this method does not read any tokens.

Parameters:

token - the expected token

Throws:

XPathException - if the current token is not the expected token

grumble

public void grumble(String message)
             throws XPathException

Report a syntax error (a static error with error code XP0003)

Parameters:

message - the error message

Throws:

XPathException - always thrown: an exception containing the supplied message

grumble

public void grumble(String message,
                    String errorCode)
             throws XPathException

Report a static error

Parameters:

message - the error message

errorCode - the error code

Throws:

XPathException - always thrown: an exception containing the supplied message

grumble

public void grumble(String message,
                    String errorCode,
                    int offset)
             throws XPathException

Report a static error, with location information

Parameters:

message - the error message

errorCode - the error code

offset - the coded location of the error, or -1 if the location of the current token should be used

Throws:

XPathException - always thrown: an exception containing the supplied message

grumble

protected void grumble(String message,
                       StructuredQName errorCode,
                       int offset)
                throws XPathException

Report a static error

Parameters:

message - the error message

errorCode - the error code

offset - the coded location of the error, or -1 if the location of the current token should be used

Throws:

XPathException - always thrown: an exception containing the supplied message

warning

protected void warning(String message)
                throws XPathException

Output a warning message

Parameters:

message - the text of the message

Throws:

XPathException

setLanguage

public void setLanguage(int language,
                        DecimalValue version)

Set the current language (XPath or XQuery, XSLT Pattern, or SequenceType)

Parameters:

language - one of the constants XPATH, XQUERY, XSLT_PATTERN, SEQUENCE_TYPE

version - The XPath or XQuery language version. For XQuery the value must be "1.0" or "3.0; for XPath it must be "2.0" or "3.0". Currently support for XQuery 3.0 and XPath 3.0 is incomplete: check the release notes.

getLanguage

protected String getLanguage()

Get the current language (XPath or XQuery)

Returns:

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

currentTokenDisplay

protected String currentTokenDisplay()

Display the current token in an error message

Returns:

the display representation of the token

parse

public Expression parse(String expression,
                        int start,
                        int terminator,
                        int lineNumber,
                        StaticContext env)
                 throws XPathException

Parse a string representing an expression. This will accept an XPath expression if called on an ExpressionParser, or an XQuery expression if called on a QueryParser.

Parameters:

expression - the expression expressed as a String

start - offset within the string where parsing is to start

terminator - character to treat as terminating the expression

lineNumber - location of the start of the expression, for diagnostics

env - the static context for the expression

Returns:

an Expression object representing the result of parsing

Throws:

XPathException - if the expression contains a syntax error

parseSequenceType

public SequenceType parseSequenceType(String input,
                                      StaticContext env)
                               throws XPathException

Parse a string representing a sequence type

Parameters:

input - the string, which should conform to the XPath SequenceType production

env - the static context

Returns:

a SequenceType object representing the type

Throws:

XPathException - if any error is encountered

parseExpression

public Expression parseExpression()
                           throws XPathException

Parse a top-level Expression: ExprSingle ( ',' ExprSingle )*

Returns:

the Expression object that results from parsing

Throws:

XPathException - if the expression contains a syntax error

parseExprSingle

public Expression parseExprSingle()
                           throws XPathException

Parse an ExprSingle

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, so the XPath version of this method throws an error unconditionally

Returns:

the expression that results from the parsing

Throws:

XPathException

parseSwitchExpression

protected Expression parseSwitchExpression()
                                    throws XPathException

Parse a Switch Expression. This construct is XQuery-1.1 only, so the XPath and XQuery 1.0 versions of this method throw an error unconditionally

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, so the XPath version of this method throws an error unconditionally

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 This construct is XQuery-only, so the XPath version of this method throws an error unconditionally

Returns:

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

Throws:

XPathException

parseTryCatchExpression

protected Expression parseTryCatchExpression()
                                      throws XPathException

Parse a try/catch Expression This construct is XQuery-1.1 only, so the XPath version of this method throws an error unconditionally

Returns:

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

Throws:

XPathException

parseForExpression

protected Expression parseForExpression()
                                 throws XPathException

Parse a FOR expression: for $x in expr (',' $y in expr)* 'return' expr

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parseSequenceType

public SequenceType parseSequenceType()
                               throws XPathException

Parse the sequence type production. The QName must be the name of a built-in schema-defined data type.

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parseItemType

protected ItemType parseItemType()
                          throws XPathException

Parse an ItemType within a SequenceType

Throws:

XPathException

parseFunctionItemType

protected ItemType parseFunctionItemType()
                                  throws XPathException

Get the item type used for function items (XQuery 1.1 higher order functions)

Throws:

XPathException

parseParenthesizedItemType

protected ItemType parseParenthesizedItemType()
                                       throws XPathException

Parse a parenthesized item type (allowed in XQuery 1.1 only)

Throws:

XPathException

parseUnionExpression

protected Expression parseUnionExpression()
                                   throws XPathException

Parse a UnionExpr:
IntersectExceptExpr ( "|" | "union" IntersectExceptExpr )*

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

atStartOfRelativePath

protected boolean atStartOfRelativePath()

Test whether the current token is one that can start a RelativePathExpression

Returns:

the resulting subexpression

disallowedAtStartOfRelativePath

protected boolean disallowedAtStartOfRelativePath()

Test whether the current token is one that is disallowed after a "leading lone slash". These composite tokens have been parsed as operators, but are not allowed after "/" under the rules of erratum E24

Returns:

the resulting subexpression

parsePathExpression

protected Expression parsePathExpression()
                                  throws XPathException

Parse a PathExpresssion. This includes "true" path expressions such as A/B/C, and also constructs that may start a path expression such as a variable reference $name or a parenthesed expression (A|B). Numeric and string literals also come under this heading.

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parseRelativePath

protected Expression parseRelativePath()
                                throws XPathException

Parse a relative path (a sequence of steps). Called when the current token immediately follows a separator (/ or //), or an implicit separator (XYZ is equivalent to ./XYZ)

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parseRemainingPath

protected Expression parseRemainingPath(Expression start)
                                 throws XPathException

Parse the remaining steps of an absolute path expression (one starting in "/" or "//"). Note that the token immediately after the "/" or "//" has already been read, and in the case of "/", it has been confirmed that we have a path expression starting with "/" rather than a standalone "/" expression.

Parameters:

start - the initial implicit expression: root() in the case of "/", root()/descendant-or-self::node in the case of "//"

Returns:

the completed path expression

Throws:

XPathException

parseStepExpression

protected Expression parseStepExpression(boolean firstInPattern)
                                  throws XPathException

Parse a step (including an optional sequence of predicates)

Parameters:

firstInPattern - true only if we are parsing the first step in a RelativePathPattern in the XSLT Pattern syntax

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parsePredicate

protected Expression parsePredicate()
                             throws XPathException

Parse the expression within a predicate. A separate method so it can be overridden

Throws:

XPathException

parseBasicStep

protected Expression parseBasicStep(boolean firstInPattern)
                             throws XPathException

Parse a basic step expression (without the predicates)

Parameters:

firstInPattern - true only if we are parsing the first step in a RelativePathPattern in the XSLT Pattern syntax

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

parseNumericLiteral

protected Expression parseNumericLiteral()
                                  throws XPathException

Throws:

XPathException

parseStringLiteral

protected Expression parseStringLiteral()
                                 throws XPathException

Throws:

XPathException

parseVariableReference

protected Expression parseVariableReference()
                                     throws XPathException

Throws:

XPathException

makeStringLiteral

protected Literal makeStringLiteral(String currentTokenValue)
                             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. Note that the job of handling doubled string delimiters is done by the tokenizer.

Parameters:

currentTokenValue - the token as read (excluding quotation marks)

Returns:

The string value of the string literal

Throws:

XPathException

parseConstructor

protected Expression parseConstructor()
                               throws XPathException

Parse a node constructor. This is allowed only in XQuery, so the method throws an error for XPath.

Returns:

the expression that results from the parsing

Throws:

XPathException

parseDynamicFunctionCall

protected Expression parseDynamicFunctionCall(Expression functionItem)
                                       throws XPathException

Parse a dynamic function call

Returns:

the expression that results from the parsing

Throws:

XPathException

parseNodeTest

protected NodeTest parseNodeTest(short nodeType)
                          throws XPathException

Parse a NodeTest. One of QName, prefix:*, *:suffix, *, text(), node(), comment(), or processing-instruction(literal?), or element(~,~), attribute(~,~), etc.

Parameters:

nodeType - the node type being sought if one is specified

Returns:

the resulting NodeTest object

Throws:

XPathException - if any error is encountered

isNamespaceTestAllowed

protected boolean isNamespaceTestAllowed()

Ask whether the syntax namespace-node() is allowed in a node kind test.

Returns:

false (currently allowed only in XQuery 1.1)

parseFunctionCall

protected Expression parseFunctionCall()
                                throws XPathException

Parse a function call. function-name '(' ( Expression (',' Expression )* )? ')'

Returns:

the resulting subexpression

Throws:

XPathException - if any error is encountered

resolveFunctionName

protected StructuredQName resolveFunctionName(String fname)
                                       throws XPathException

Throws:

XPathException

parseFunctionArgument

protected Expression parseFunctionArgument()
                                    throws XPathException

Parse an argument to a function call. Separate method so it can be overridden. With higher-order-function syntax in XPath 3.0/XQuery 3.0, this returns null if the pseudo-argument "?" is found.

Throws:

XPathException

parseLiteralFunctionItem

protected Expression parseLiteralFunctionItem()
                                       throws XPathException

Parse a literal function item (introduced in XQuery 1.1) Syntax: QName # integer The QName and # have already been read

Returns:

an ExternalObject representing the function item

Throws:

XPathException

parseInlineFunction

protected Expression parseInlineFunction()
                                  throws XPathException

Parse an inline function "function" "(" ParamList? ")" ("as" SequenceType)? EnclosedExpr On entry, "function (" has already been read

Throws:

XPathException - if a syntax error is found

makeCurriedFunction

protected Expression makeCurriedFunction(FunctionCall fcall,
                                         Expression[] args,
                                         IntSet placeMarkers)
                                  throws XPathException

Process a function call in which one or more of the argument positions are represented as "?" placemarkers (indicating partial application or currying)

Parameters:

fcall - the function call (as if there were no currying)

args - the arguments (with EmptySequence in the placemarker positions)

placeMarkers - the positions of the placemarkers

Returns:

the curried function

Throws:

XPathException

getRangeVariables

public Stack<Binding> getRangeVariables()

Get the stack of in-scope range variables

Returns:

the stack of variables

setRangeVariables

public void setRangeVariables(Stack<Binding> variables)

Set a new stack of in-scope range variables

Parameters:

variables - the stack of variables

declareRangeVariable

public void declareRangeVariable(Binding declaration)
                          throws XPathException

Declare a range variable (record its existence within the parser). A range variable is a variable declared within an expression, as distinct from a variable declared in the context.

Parameters:

declaration - the variable declaration to be added to the stack

Throws:

XPathException - if any error is encountered

undeclareRangeVariable

public void undeclareRangeVariable()

Note when the most recently declared range variable has gone out of scope

findRangeVariable

protected Binding findRangeVariable(StructuredQName qName)

Locate a range variable with a given name. (By "range variable", we mean a variable declared within the expression where it is used.)

Parameters:

qName - identifies the name of the range variable

Returns:

null if not found (this means the variable is probably a context variable); otherwise the relevant RangeVariable

setRangeVariableStack

public void setRangeVariableStack(Stack<Binding> stack)

Set the range variable stack. Used when parsing a nested subexpression inside an attribute constructor.

Parameters:

stack - the stack to be used for local variables declared within the expression

makeNameCode

public final int makeNameCode(String qname,
                              boolean useDefault)
                       throws XPathException

Make a NameCode, using the static context for namespace resolution

Parameters:

qname - The name as written, in the form "[prefix:]localname"; alternatively, a QName in Clark notation ({uri}local)

useDefault - Defines the action when there is no prefix. If true, use the default namespace URI for element names. If false, use no namespace URI (as for attribute names).

Returns:

the namecode, which can be used to identify this name in the name pool

Throws:

XPathException - if the name is invalid, or the prefix undeclared

makeNameCodeSilently

public final int makeNameCodeSilently(String qname,
                                      boolean useDefault)
                               throws XPathException,
                                      QNameException

Make a NameCode, using the static context for namespace resolution. This variant of the method does not call "grumble" to report any errors to the ErrorListener, it only reports errors by throwing exceptions. This allows the caller to control the message output.

Parameters:

qname - The name as written, in the form "[prefix:]localname"

useDefault - Defines the action when there is no prefix. If true, use the default namespace URI for element names. If false, use no namespace URI (as for attribute names).

Returns:

the namecode, which can be used to identify this name in the name pool

Throws:

XPathException - if the name is invalid, or the prefix undeclared

QNameException

makeStructuredQName

public final StructuredQName makeStructuredQName(String qname,
                                                 boolean useDefault)
                                          throws XPathException

Make a Structured QName, using the static context for namespace resolution

Parameters:

qname - The name as written, in the form "[prefix:]localname"; alternatively, a QName in Clark format ({uri}local)

useDefault - Defines the action when there is no prefix. If true, use the default namespace URI for element names. If false, use no namespace URI (as for attribute names).

Returns:

the namecode, which can be used to identify this name in the name pool

Throws:

XPathException - if the name is invalid, or the prefix undeclared

makeNameTest

public NameTest makeNameTest(short nodeType,
                             String qname,
                             boolean useDefault)
                      throws XPathException

Make a NameTest, using the static context for namespace resolution

Parameters:

nodeType - the type of node required (identified by a constant in class Type)

qname - the lexical QName of the required node; alternatively, a QName in Clark notation ({uri}local)

useDefault - true if the default namespace should be used when the QName is unprefixed

Returns:

a NameTest, representing a pattern that tests for a node of a given node kind and a given name

Throws:

XPathException - if the QName is invalid

makeNamespaceTest

public NamespaceTest makeNamespaceTest(short nodeType,
                                       String prefix)
                                throws XPathException

Make a NamespaceTest (name:*)

Parameters:

nodeType - integer code identifying the type of node required

prefix - the namespace prefix

Returns:

the NamespaceTest, a pattern that matches all nodes in this namespace

Throws:

XPathException - if the namespace prefix is not declared

makeLocalNameTest

public LocalNameTest makeLocalNameTest(short nodeType,
                                       String localName)
                                throws XPathException

Make a LocalNameTest (*:name)

Parameters:

nodeType - the kind of node to be matched

localName - the requred local name

Returns:

a LocalNameTest, a pattern which matches all nodes of a given local name, regardless of namespace

Throws:

XPathException - if the local name is invalid

setLocation

protected void setLocation(Expression exp)

Set location information on an expression. At present this consists of a simple line number. Needed mainly for XQuery.

Parameters:

exp - the expression whose location information is to be set

setLocation

public void setLocation(Expression exp,
                        int offset)

Set location information on an expression. At present only the line number is retained. Needed mainly for XQuery. This version of the method supplies an explicit offset (character position within the expression or query), which the tokenizer can convert to a line number and column number.

Parameters:

exp - the expression whose location information is to be set

offset - the character position within the expression (ignoring newlines)

makeTracer

public Expression makeTracer(int startOffset,
                             Expression exp,
                             int construct,
                             StructuredQName qName)

If tracing, wrap an expression in a trace instruction

Parameters:

startOffset - the position of the expression in the soruce

exp - the expression to be wrapped

construct - integer constant identifying the kind of construct

qName - the name of the construct (if applicable)

Returns:

the expression that does the tracing

isKeyword

protected boolean isKeyword(String s)

Test whether the current token is a given keyword.

Parameters:

s - The string to be compared with the current token

Returns:

true if they are the same

normalizeEQName

protected String normalizeEQName(String s)
                          throws XPathException

Normalize an EQName. This is written in the source code in the form "uri":local, but by the time it gets here it has been converted to Clark format {uri}local. This method collapses whitespace within the URI

Parameters:

s - the EQName in the form of a Clark name

Returns:

the normalized EQName

Throws:

XPathException - so that the XQuery implementation in a subclass can do so.

setScanOnly

public void setScanOnly(boolean scanOnly)

Set that we are parsing in "scan only"

Parameters:

scanOnly - true if parsing is to proceed in scan-only mode. In this mode namespace bindings are not yet known, so no attempt is made to look up namespace prefixes.