Package org.apache.xpath.compiler

Class XPathParser

java.lang.Object
org.apache.xpath.compiler.XPathParser
public class XPathParser
extends Object
Tokenizes and parses XPath expressions. This should really be named XPathParserImpl, and may be renamed in the future.

  • Field Summary

    Fields
    Modifier and Type Field Description
    static String CONTINUE_AFTER_FATAL_ERROR  
    protected static int FILTER_MATCH_FAILED
    Results from checking FilterExpr syntax
    protected static int FILTER_MATCH_PREDICATES  
    protected static int FILTER_MATCH_PRIMARY  

  • Constructor Summary

    Constructors
    Constructor Description
    XPathParser​(ErrorListener errorListener, SourceLocator sourceLocator)
    The parser constructor.

  • Method Summary

    Modifier and Type Method Description
    protected boolean AbbreviatedNodeTestStep​(boolean isLeadingSlashPermitted)
    AbbreviatedNodeTestStep ::= '@'? NodeTest Predicate
    protected int AdditiveExpr​(int addPos)
    This has to handle construction of the operations so that they are evaluated in pre-fix order.
    protected void AndExpr()
    AndExpr ::= EqualityExpr | AndExpr 'and' EqualityExpr
    protected void Argument()
    Argument ::= Expr
    protected int AxisName()
    Basis ::= AxisName '::' NodeTest | AbbreviatedBasis
    protected void Basis()
    Basis ::= AxisName '::' NodeTest | AbbreviatedBasis
    protected void BooleanExpr()
    StringExpr ::= Expr
    protected String dumpRemainingTokenQueue()
    Dump the remaining token queue.
    protected int EqualityExpr​(int addPos)  
    protected void Expr()
    Expr ::= OrExpr
    protected int FilterExpr()
    FilterExpr ::= PrimaryExpr | FilterExpr Predicate
    protected boolean FunctionCall()
    FunctionCall ::= FunctionName '(' ( Argument ( ',' Argument)*)? ')'
    ErrorListener getErrorListener()
    Return the current error listener.
    protected void IdKeyPattern()
    IdKeyPattern ::= 'id' '(' Literal ')' | 'key' '(' Literal ',' Literal ')' (Also handle doc())
    void initMatchPattern​(Compiler compiler, String expression, PrefixResolver namespaceContext)
    Given an string, init an XPath object for pattern matches, in order that a parse doesn't have to be done each time the expression is evaluated.
    void initXPath​(Compiler compiler, String expression, PrefixResolver namespaceContext)
    Given an string, init an XPath object for selections, in order that a parse doesn't have to be done each time the expression is evaluated.
    protected void Literal()
    The value of the Literal is the sequence of characters inside the " or ' characters>.
    protected void LocationPath()
    LocationPath ::= RelativeLocationPath | AbsoluteLocationPath
    protected void LocationPathPattern()
    LocationPathPattern ::= '/' RelativePathPattern? | IdKeyPattern (('/' | '//') RelativePathPattern)? | '//'? RelativePathPattern
    protected int MultiplicativeExpr​(int addPos)
    This has to handle construction of the operations so that they are evaluated in pre-fix order.
    protected void NCName()
    NCName ::= (Letter | '_') (NCNameChar) NCNameChar ::= Letter | Digit | '.' | '-' | '_' | CombiningChar | Extender
    protected void NodeTest​(int axesType)
    NodeTest ::= WildcardName | NodeType '(' ')' | 'processing-instruction' '(' Literal ')'
    protected void Number()
    Number ::= [0-9]+('.'[0-9]+)? | '.'[0-9]+
    protected void NumberExpr()
    NumberExpr ::= Expr
    protected void OrExpr()
    OrExpr ::= AndExpr | OrExpr 'or' AndExpr
    protected void PathExpr()
    PathExpr ::= LocationPath | FilterExpr | FilterExpr '/' RelativeLocationPath | FilterExpr '//' RelativeLocationPath
    protected void Pattern()
    Pattern ::= LocationPathPattern | Pattern '|' LocationPathPattern
    protected void Predicate()
    Predicate ::= '[' PredicateExpr ']'
    protected void PredicateExpr()
    PredicateExpr ::= Expr
    protected boolean PrimaryExpr()
    PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
    protected void QName()
    QName ::= (Prefix ':')? LocalPart Prefix ::= NCName LocalPart ::= NCName
    protected int RelationalExpr​(int addPos)
    .
    protected boolean RelativeLocationPath()
    RelativeLocationPath ::= Step | RelativeLocationPath '/' Step | AbbreviatedRelativeLocationPath
    protected void RelativePathPattern()
    RelativePathPattern ::= StepPattern | RelativePathPattern '/' StepPattern | RelativePathPattern '//' StepPattern
    void setErrorHandler​(ErrorListener handler)
    Allow an application to register an error event handler, where syntax errors will be sent.
    protected boolean Step()
    Step ::= Basis Predicate | AbbreviatedStep
    protected boolean StepPattern​(boolean isLeadingSlashPermitted)
    StepPattern ::= AbbreviatedNodeTestStep
    protected void StringExpr()
    StringExpr ::= Expr
    protected void UnaryExpr()
    UnaryExpr ::= UnionExpr | '-' UnaryExpr
    protected void UnionExpr()
    The context of the right hand side expressions is the context of the left hand side expression.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • CONTINUE_AFTER_FATAL_ERROR

      public static final String CONTINUE_AFTER_FATAL_ERROR
      See Also:
      Constant Field Values

    • FILTER_MATCH_FAILED

      protected static final int FILTER_MATCH_FAILED
      Results from checking FilterExpr syntax
      See Also:
      Constant Field Values

    • FILTER_MATCH_PRIMARY

      protected static final int FILTER_MATCH_PRIMARY
      See Also:
      Constant Field Values

    • FILTER_MATCH_PREDICATES

      protected static final int FILTER_MATCH_PREDICATES
      See Also:
      Constant Field Values

  • Constructor Details

  • Method Details

    • initXPath

      public void initXPath​(Compiler compiler, String expression, PrefixResolver namespaceContext) throws TransformerException
      Given an string, init an XPath object for selections, in order that a parse doesn't have to be done each time the expression is evaluated.
      Parameters:
      compiler - The compiler object.
      expression - A string conforming to the XPath grammar.
      namespaceContext - An object that is able to resolve prefixes in the XPath to namespaces.
      Throws:
      TransformerException

    • initMatchPattern

      public void initMatchPattern​(Compiler compiler, String expression, PrefixResolver namespaceContext) throws TransformerException
      Given an string, init an XPath object for pattern matches, in order that a parse doesn't have to be done each time the expression is evaluated.
      Parameters:
      compiler - The XPath object to be initialized.
      expression - A String representing the XPath.
      namespaceContext - An object that is able to resolve prefixes in the XPath to namespaces.
      Throws:
      TransformerException

    • setErrorHandler

      public void setErrorHandler​(ErrorListener handler)
      Allow an application to register an error event handler, where syntax errors will be sent. If the error listener is not set, syntax errors will be sent to System.err.
      Parameters:
      handler - Reference to error listener where syntax errors will be sent.

    • getErrorListener

      public ErrorListener getErrorListener()
      Return the current error listener.
      Returns:
      The error listener, which should not normally be null, but may be.

    • dumpRemainingTokenQueue

      protected String dumpRemainingTokenQueue()
      Dump the remaining token queue. Thanks to Craig for this.
      Returns:
      A dump of the remaining token queue, which may be appended to an error message.

    • Expr

      protected void Expr() throws TransformerException
      Expr ::= OrExpr
      Throws:
      TransformerException

    • OrExpr

      protected void OrExpr() throws TransformerException
      OrExpr ::= AndExpr | OrExpr 'or' AndExpr
      Throws:
      TransformerException

    • AndExpr

      protected void AndExpr() throws TransformerException
      AndExpr ::= EqualityExpr | AndExpr 'and' EqualityExpr
      Throws:
      TransformerException

    • EqualityExpr

      protected int EqualityExpr​(int addPos) throws TransformerException
      Parameters:
      addPos - Position where expression is to be added, or -1 for append.
      Returns:
      the position at the end of the equality expression.
      Throws:
      TransformerException

    • RelationalExpr

      protected int RelationalExpr​(int addPos) throws TransformerException
      .
      Parameters:
      addPos - Position where expression is to be added, or -1 for append.
      Returns:
      the position at the end of the relational expression.
      Throws:
      TransformerException

    • AdditiveExpr

      protected int AdditiveExpr​(int addPos) throws TransformerException
      This has to handle construction of the operations so that they are evaluated in pre-fix order. So, for 9+7-6, instead of |+|9|-|7|6|, this needs to be evaluated as |-|+|9|7|6|. AdditiveExpr ::= MultiplicativeExpr | AdditiveExpr '+' MultiplicativeExpr | AdditiveExpr '-' MultiplicativeExpr
      Parameters:
      addPos - Position where expression is to be added, or -1 for append.
      Returns:
      the position at the end of the equality expression.
      Throws:
      TransformerException

    • MultiplicativeExpr

      protected int MultiplicativeExpr​(int addPos) throws TransformerException
      This has to handle construction of the operations so that they are evaluated in pre-fix order. So, for 9+7-6, instead of |+|9|-|7|6|, this needs to be evaluated as |-|+|9|7|6|. MultiplicativeExpr ::= UnaryExpr | MultiplicativeExpr MultiplyOperator UnaryExpr | MultiplicativeExpr 'div' UnaryExpr | MultiplicativeExpr 'mod' UnaryExpr | MultiplicativeExpr 'quo' UnaryExpr
      Parameters:
      addPos - Position where expression is to be added, or -1 for append.
      Returns:
      the position at the end of the equality expression.
      Throws:
      TransformerException

    • UnaryExpr

      protected void UnaryExpr() throws TransformerException
      UnaryExpr ::= UnionExpr | '-' UnaryExpr
      Throws:
      TransformerException

    • StringExpr

      protected void StringExpr() throws TransformerException
      StringExpr ::= Expr
      Throws:
      TransformerException

    • BooleanExpr

      protected void BooleanExpr() throws TransformerException
      StringExpr ::= Expr
      Throws:
      TransformerException

    • NumberExpr

      protected void NumberExpr() throws TransformerException
      NumberExpr ::= Expr
      Throws:
      TransformerException

    • UnionExpr

      protected void UnionExpr() throws TransformerException
      The context of the right hand side expressions is the context of the left hand side expression. The results of the right hand side expressions are node sets. The result of the left hand side UnionExpr is the union of the results of the right hand side expressions. UnionExpr ::= PathExpr | UnionExpr '|' PathExpr
      Throws:
      TransformerException

    • PathExpr

      protected void PathExpr() throws TransformerException
      PathExpr ::= LocationPath | FilterExpr | FilterExpr '/' RelativeLocationPath | FilterExpr '//' RelativeLocationPath
      Throws:
      XSLProcessorException - thrown if the active ProblemListener and XPathContext decide the error condition is severe enough to halt processing.
      TransformerException

    • FilterExpr

      protected int FilterExpr() throws TransformerException
      FilterExpr ::= PrimaryExpr | FilterExpr Predicate
      Returns:
      FILTER_MATCH_PREDICATES, if this method successfully matched a FilterExpr with one or more Predicates; FILTER_MATCH_PRIMARY, if this method successfully matched a FilterExpr that was just a PrimaryExpr; or FILTER_MATCH_FAILED, if this method did not match a FilterExpr
      Throws:
      XSLProcessorException - thrown if the active ProblemListener and XPathContext decide the error condition is severe enough to halt processing.
      TransformerException

    • PrimaryExpr

      protected boolean PrimaryExpr() throws TransformerException
      PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
      Returns:
      true if this method successfully matched a PrimaryExpr
      Throws:
      TransformerException

    • Argument

      protected void Argument() throws TransformerException
      Argument ::= Expr
      Throws:
      TransformerException

    • FunctionCall

      protected boolean FunctionCall() throws TransformerException
      FunctionCall ::= FunctionName '(' ( Argument ( ',' Argument)*)? ')'
      Returns:
      true if, and only if, a FunctionCall was matched
      Throws:
      TransformerException

    • LocationPath

      protected void LocationPath() throws TransformerException
      LocationPath ::= RelativeLocationPath | AbsoluteLocationPath
      Throws:
      TransformerException

    • RelativeLocationPath

      protected boolean RelativeLocationPath() throws TransformerException
      RelativeLocationPath ::= Step | RelativeLocationPath '/' Step | AbbreviatedRelativeLocationPath
      Throws:
      TransformerException

    • Step

      protected boolean Step() throws TransformerException
      Step ::= Basis Predicate | AbbreviatedStep
      Throws:
      TransformerException

    • Basis

      protected void Basis() throws TransformerException
      Basis ::= AxisName '::' NodeTest | AbbreviatedBasis
      Throws:
      TransformerException

    • AxisName

      protected int AxisName() throws TransformerException
      Basis ::= AxisName '::' NodeTest | AbbreviatedBasis
      Returns:
      FROM_XXX axes type, found in Keywords.
      Throws:
      TransformerException

    • NodeTest

      protected void NodeTest​(int axesType) throws TransformerException
      NodeTest ::= WildcardName | NodeType '(' ')' | 'processing-instruction' '(' Literal ')'
      Parameters:
      axesType - FROM_XXX axes type, found in Keywords.
      Throws:
      TransformerException

    • Predicate

      protected void Predicate() throws TransformerException
      Predicate ::= '[' PredicateExpr ']'
      Throws:
      TransformerException

    • PredicateExpr

      protected void PredicateExpr() throws TransformerException
      PredicateExpr ::= Expr
      Throws:
      TransformerException

    • QName

      protected void QName() throws TransformerException
      QName ::= (Prefix ':')? LocalPart Prefix ::= NCName LocalPart ::= NCName
      Throws:
      TransformerException

    • NCName

      protected void NCName()
      NCName ::= (Letter | '_') (NCNameChar) NCNameChar ::= Letter | Digit | '.' | '-' | '_' | CombiningChar | Extender

    • Literal

      protected void Literal() throws TransformerException
      The value of the Literal is the sequence of characters inside the " or ' characters>. Literal ::= '"' [^"]* '"' | "'" [^']* "'"
      Throws:
      TransformerException

    • Number

      protected void Number() throws TransformerException
      Number ::= [0-9]+('.'[0-9]+)? | '.'[0-9]+
      Throws:
      TransformerException

    • Pattern

      protected void Pattern() throws TransformerException
      Pattern ::= LocationPathPattern | Pattern '|' LocationPathPattern
      Throws:
      TransformerException

    • LocationPathPattern

      protected void LocationPathPattern() throws TransformerException
      LocationPathPattern ::= '/' RelativePathPattern? | IdKeyPattern (('/' | '//') RelativePathPattern)? | '//'? RelativePathPattern
      Throws:
      TransformerException

    • IdKeyPattern

      protected void IdKeyPattern() throws TransformerException
      IdKeyPattern ::= 'id' '(' Literal ')' | 'key' '(' Literal ',' Literal ')' (Also handle doc())
      Throws:
      TransformerException

    • RelativePathPattern

      protected void RelativePathPattern() throws TransformerException
      RelativePathPattern ::= StepPattern | RelativePathPattern '/' StepPattern | RelativePathPattern '//' StepPattern
      Throws:
      TransformerException

    • StepPattern

      protected boolean StepPattern​(boolean isLeadingSlashPermitted) throws TransformerException
      StepPattern ::= AbbreviatedNodeTestStep
      Parameters:
      isLeadingSlashPermitted - a boolean indicating whether a slash can appear at the start of this step
      Returns:
      boolean indicating whether a slash following the step was consumed
      Throws:
      TransformerException

    • AbbreviatedNodeTestStep

      protected boolean AbbreviatedNodeTestStep​(boolean isLeadingSlashPermitted) throws TransformerException
      AbbreviatedNodeTestStep ::= '@'? NodeTest Predicate
      Parameters:
      isLeadingSlashPermitted - a boolean indicating whether a slash can appear at the start of this step
      Returns:
      boolean indicating whether a slash following the step was consumed
      Throws:
      TransformerException