ExpressionParser

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

Direct Known Subclasses:

PatternParser20, 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

Nested Classes
Modifier and Type	Class and Description
`protected static class`	`ExpressionParser.TemporaryContainer` A Container used on a temporary basis to hold an expression while it is being parsed

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`allowXPath30Syntax`
`protected int`	`catchDepth`
`protected CodeInjector`	`codeInjector`
`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

Constructors
Constructor and Description

ExpressionParser()
Create an expression parser

Constructors
Constructor and Description
`ExpressionParser()` Create an expression parser

Method Summary

Methods
Modifier and Type	Method and Description
`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
`protected void`	`customizeTokenizer(Tokenizer t)` Callback to tailor the tokenizer
`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.
`CodeInjector`	`getCodeInjector()` Set a CodeInjector which can be used to modify or wrap expressions on the tree as the expression is parsed and the tree is constructed.
`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 XPST0003)
`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
`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 boolean`	`isReservedInQuery(String uri)`
`protected Expression`	`makeCurriedFunction(int offset, StructuredQName name, 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
`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
`NodeName`	`makeNodeName(String qname, boolean useDefault)` Make a FingerprintedQName, 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, String defaultUri)` Make a Structured QName, using the static context for namespace resolution
`StructuredQName`	`makeStructuredQNameSilently(String qname, String defaultUri)` Make a NameCode, 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 Map<StructuredQName,Annotation>`	`parseAnnotations()`
`protected Expression`	`parseBasicStep(boolean firstInPattern)` Parse a basic step expression (without the predicates)
`Expression`	`parseBinaryExpression(Expression lhs, int minPrecedence)` Parse a binary expression, using operator precedence parsing.
`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`	`parseFLWORExpression()` Parse a FOR or LET expression: for $x in expr (',' $y in expr)* 'return' expr let $x := expr (', $y := expr)* 'return' expr This version of the method handles the subset of the FLWOR syntax allowed in XPath
`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 (XPath 3.0 higher order functions)
`protected Expression`	`parseInlineFunction(Map<StructuredQName,Annotation> annotations)` Parse an inline function "function" "(" ParamList? ")" ("as" SequenceType)? EnclosedExpr On entry, "function (" has already been read
`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 Expression`	`parseMapExpression()` Parse a map expression.
`protected ItemType`	`parseMapItemType()` Get the item type used for map items (XPath 3.0)
`protected NodeTest`	`parseNodeTest(short nodeType)` Parse a NodeTest.
`protected Expression`	`parseNumericLiteral()`
`protected ItemType`	`parseParenthesizedItemType()` Parse a parenthesized item type (XPath 3.0)
`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`	`parseSimpleMappingExpression()` Parse an XPath 3.0 simple mapping expression ("!" operator)
`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-3.0 only, so the XPath version of this method throws an error unconditionally
`protected Expression`	`parseTypePattern()` Parse a Type Pattern This construct is used only in XSLT patterns, so the XPath version of this method throws an error unconditionally
`protected Expression`	`parseTypeswitchExpression()` Parse a Typeswitch Expression.
`protected Expression`	`parseValidateExpression()` Parse a Validate Expression.
`protected Expression`	`parseVariableReference()`
`Expression`	`reportMissingFunction(int offset, StructuredQName functionName, Expression[] arguments)`
`protected StructuredQName`	`resolveFunctionName(String fname)` Interpret a function name, returning it as a resolved QName
`void`	`setCodeInjector(CodeInjector injector)` Set a CodeInjector which can be used to modify or wrap expressions on the tree as the expression is parsed and the tree is constructed.
`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)
`void`	`setLocation(Clause clause, int offset)` Set location information on a clause of a FLWOR expression.
`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"
`protected void`	`testPermittedAxis(byte axis)`
`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
```
  - codeInjector
```
protected CodeInjector codeInjector
```
  - 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
```
  - catchDepth
```
protected int catchDepth
```
- Constructor Detail
  - ExpressionParser
```
public ExpressionParser()
```
    Create an expression parser
- Method Detail
  - setCodeInjector
```
public void setCodeInjector(CodeInjector injector)
```
    Set a CodeInjector which can be used to modify or wrap expressions on the tree as the expression is parsed and the tree is constructed. This is typically used to add tracing code.
    
    Parameters:
    injector - the code injector to be used
  - getCodeInjector
```
public CodeInjector getCodeInjector()
```
    Set a CodeInjector which can be used to modify or wrap expressions on the tree as the expression is parsed and the tree is constructed. This is typically used to add tracing code.
    
    Returns:
    the code injector in use, if any; or null otherwise
  - 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 - if an invalid token is found
  - 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 XPST0003)
    
    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 - if the message cannot be output
  - 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
  - customizeTokenizer
```
protected void customizeTokenizer(Tokenizer t)
```
    Callback to tailor the tokenizer
    
    Parameters:
    t - the Tokenizer to be customized
  - 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
  - parseBinaryExpression
```
public Expression parseBinaryExpression(Expression lhs,
                               int minPrecedence)
                                 throws XPathException
```
    Parse a binary expression, using operator precedence parsing. This is used to parse the part of the grammary consisting largely of binary operators distinguished by precedence: from "or expressions" down to "unary expressions". Algorithm for the mainstream binary operators is from Wikipedia article on precedence parsing; operator precedences are from the XQuery specification appendix B.
    
    Parameters:
    lhs - Left-hand side "basic expression"
    minPrecedence - the minimum precedence of an operator that is to be treated as not terminating the current expression
    
    Returns:
    the parsed expression
    
    Throws:
    
    XPathException - if a static error is found
  - 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 - if a static error is found
  - 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 - if a static error is found
  - 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 - if a static error is found
  - 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 - if a static error is found
  - parseTypePattern
```
protected Expression parseTypePattern()
                               throws XPathException
```
    Parse a Type Pattern This construct is used only in XSLT patterns, 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 - if a static error is found
  - parseTryCatchExpression
```
protected Expression parseTryCatchExpression()
                                      throws XPathException
```
    Parse a try/catch Expression This construct is XQuery-3.0 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 - if a static error is found
  - parseFLWORExpression
```
protected Expression parseFLWORExpression()
                                   throws XPathException
```
    Parse a FOR or LET expression: for $x in expr (',' $y in expr)* 'return' expr let $x := expr (', $y := expr)* 'return' expr This version of the method handles the subset of the FLWOR syntax allowed in XPath
    
    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
```
public ItemType parseItemType()
                       throws XPathException
```
    Parse an ItemType within a SequenceType
    
    Returns:
    the ItemType after parsing
    
    Throws:
    
    XPathException - if a static error is found
  - parseFunctionItemType
```
protected ItemType parseFunctionItemType()
                                  throws XPathException
```
    Get the item type used for function items (XPath 3.0 higher order functions)
    
    Returns:
    the item type representing a function item
    
    Throws:
    
    XPathException - if a static error occurs (including the case where XPath 3.0 syntax is not enabled)
  - parseMapItemType
```
protected ItemType parseMapItemType()
                             throws XPathException
```
    Get the item type used for map items (XPath 3.0)
    
    Returns:
    the item type of the map
    
    Throws:
    
    XPathException - if a parsing error occurs or if the map syntax is not available
  - parseParenthesizedItemType
```
protected ItemType parseParenthesizedItemType()
                                       throws XPathException
```
    Parse a parenthesized item type (XPath 3.0)
    
    Returns:
    the item type
    
    Throws:
    
    XPathException - if a syntax error is found
  - 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
  - parseSimpleMappingExpression
```
protected Expression parseSimpleMappingExpression()
                                           throws XPathException
```
    Parse an XPath 3.0 simple mapping expression ("!" operator)
    
    Throws:
    
    XPathException
  - 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 - if a static error is found
  - 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
    
    Returns:
    the expression within the predicate
    
    Throws:
    
    XPathException - if a static error is found
  - parseAnnotations
```
protected Map<StructuredQName,Annotation> parseAnnotations()
                                                    throws XPathException
```
    Throws:
    
    XPathException
  - isReservedInQuery
```
protected boolean isReservedInQuery(String uri)
```
  - 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
  - testPermittedAxis
```
protected void testPermittedAxis(byte axis)
                          throws XPathException
```
    Throws:
    
    XPathException
  - 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 - if a static error is found
  - 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 - if a static error occurs
  - parseDynamicFunctionCall
```
protected Expression parseDynamicFunctionCall(Expression functionItem)
                                       throws XPathException
```
    Parse a dynamic function call
    
    Parameters:
    functionItem - the expression that determines the function to be called
    
    Returns:
    the expression that results from the parsing
    
    Throws:
    
    XPathException - if a static error is found
  - 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 3.0)
  - parseMapExpression
```
protected Expression parseMapExpression()
                                 throws XPathException
```
    Parse a map expression. Requires XPath/XQuery 3.0 Provisional syntax map { expr := expr (, expr := expr )*} }
    
    Returns:
    the map expression
    
    Throws:
    
    XPathException - if a static error occurs
  - 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
  - reportMissingFunction
```
public Expression reportMissingFunction(int offset,
                               StructuredQName functionName,
                               Expression[] arguments)
                                 throws XPathException
```
    Throws:
    
    XPathException
  - resolveFunctionName
```
protected StructuredQName resolveFunctionName(String fname)
                                       throws XPathException
```
    Interpret a function name, returning it as a resolved QName
    
    Parameters:
    fname - the lexical QName used as the function name; or an EQName presented by the tokenizer as a name in Clark notation
    
    Returns:
    the Structured QName obtained by resolving any prefix in the function name
    
    Throws:
    
    XPathException - if the supplied name is not a valid QName or if its prefix is not in scope
  - parseFunctionArgument
```
public 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.
    
    Returns:
    the Expression used as the argument, or null if the argument is the place-holder "?"
    
    Throws:
    
    XPathException - if the argument expression does not parse correctly
  - 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 - if a static error is encountered
  - parseInlineFunction
```
protected Expression parseInlineFunction(Map<StructuredQName,Annotation> annotations)
                                  throws XPathException
```
    Parse an inline function "function" "(" ParamList? ")" ("as" SequenceType)? EnclosedExpr On entry, "function (" has already been read
    
    Parameters:
    annotations - the function annotations, which have already been read, or null if there are none
    
    Returns:
    the parsed inline function
    
    Throws:
    
    XPathException - if a syntax error is found
  - makeCurriedFunction
```
protected Expression makeCurriedFunction(int offset,
                             StructuredQName name,
                             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:
    offset - the position of the expression in the source text
    name - the function name (as if there were no currying)
    args - the arguments (with EmptySequence in the placemarker positions)
    placeMarkers - the positions of the placemarkers @return the curried function
    
    Returns:
    the curried function
    
    Throws:
    
    XPathException - if a static error is found
  - 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
  - makeStructuredQNameSilently
```
public final StructuredQName makeStructuredQNameSilently(String qname,
                                          String defaultUri)
                                                  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"
    defaultUri - 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 - if the name is not a lexically valid QName
  - makeStructuredQName
```
public final StructuredQName makeStructuredQName(String qname,
                                  String defaultUri)
                                          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)
    defaultUri - The URI to be used if the name is written as a localname with no prefix
    
    Returns:
    the QName as an instance of StructuredQName
    
    Throws:
    
    XPathException - if the name is invalid, or the prefix undeclared
  - makeNodeName
```
public final NodeName makeNodeName(String qname,
                    boolean useDefault)
                            throws XPathException,
                                   QNameException
```
    Make a FingerprintedQName, 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 fingerprinted QName
    
    Throws:
    
    XPathException - if the name is invalid, or the prefix undeclared
    
    QNameException - if the supplied qname is not a lexically valid QName
  - 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)
  - setLocation
```
public void setLocation(Clause clause,
               int offset)
```
    Set location information on a clause of a FLWOR 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:
    clause - the clause 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.

Class ExpressionParser

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

t

env

rangeVariables

defaultContainer

nameChecker

allowXPath30Syntax

scanOnly

codeInjector

language

XPATH

XSLT_PATTERN

SEQUENCE_TYPE

XQUERY

languageVersion

catchDepth

Constructor Detail

ExpressionParser

Method Detail

setCodeInjector

getCodeInjector

getTokenizer

getStaticContext

setDefaultContainer

getDefaultContainer

getNameChecker

nextToken

expect

grumble

grumble

grumble

grumble

warning

setLanguage

getLanguage

currentTokenDisplay

parse

customizeTokenizer

parseSequenceType

parseExpression

parseExprSingle

parseBinaryExpression

parseTypeswitchExpression

parseSwitchExpression

parseValidateExpression

parseExtensionExpression

parseTypePattern

parseTryCatchExpression

parseFLWORExpression

parseSequenceType

parseItemType

parseFunctionItemType

parseMapItemType

parseParenthesizedItemType

atStartOfRelativePath

disallowedAtStartOfRelativePath

parsePathExpression

parseSimpleMappingExpression

parseRelativePath

parseRemainingPath

parseStepExpression

parsePredicate

parseAnnotations

isReservedInQuery

parseBasicStep

testPermittedAxis

parseNumericLiteral

parseStringLiteral

parseVariableReference

makeStringLiteral

parseConstructor

parseDynamicFunctionCall

parseNodeTest

isNamespaceTestAllowed