Class QuantifiedExpression

All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, Binding, InstructionInfo, Locator

public class QuantifiedExpression extends Assignation
A QuantifiedExpression tests whether some/all items in a sequence satisfy some condition.
See Also:
  • Constructor Details

    • QuantifiedExpression

      public QuantifiedExpression()
  • Method Details

    • getExpressionName

      public String getExpressionName()
      Get a name identifying the kind of expression, in terms meaningful to a user.
      Overrides:
      getExpressionName in class Expression
      Returns:
      a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.
    • setOperator

      public void setOperator(int operator)
      Set the operator, either Token.SOME or Token.EVERY
      Parameters:
      operator - the operator
    • getOperator

      public int getOperator()
      Get the operator, either Token.SOME or Token.EVERY
      Returns:
      the operator
    • computeCardinality

      public int computeCardinality()
      Determine the static cardinality
      Specified by:
      computeCardinality in class Expression
      Returns:
      the computed cardinality, as one of the values StaticProperty.ALLOWS_ZERO_OR_ONE, StaticProperty.EXACTLY_ONE, StaticProperty.ALLOWS_ONE_OR_MORE, StaticProperty.ALLOWS_ZERO_OR_MORE
    • typeCheck

      public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
      Type-check the expression
      Overrides:
      typeCheck in class Expression
      Parameters:
      visitor - an expression visitor
      contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
      Returns:
      the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
      Throws:
      XPathException - if an error is discovered during this phase (typically a type error)
    • optimize

      public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
      Perform optimisation of an expression and its subexpressions.

      This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

      Overrides:
      optimize in class Expression
      Parameters:
      visitor - an expression visitor
      contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
      Returns:
      the original expression, rewritten if appropriate to optimize execution
      Throws:
      XPathException - if an error is discovered during this phase (typically a type error)
    • checkForUpdatingSubexpressions

      public void checkForUpdatingSubexpressions() throws XPathException
      Check to ensure that this expression does not contain any updating subexpressions. This check is overridden for those expressions that permit updating subexpressions.
      Overrides:
      checkForUpdatingSubexpressions in class Assignation
      Throws:
      XPathException - if the expression has a non-permitted updateing subexpression
    • isUpdatingExpression

      public boolean isUpdatingExpression()
      Determine whether this is an updating expression as defined in the XQuery update specification
      Overrides:
      isUpdatingExpression in class Assignation
      Returns:
      true if this is an updating expression
    • copy

      public Expression copy()
      Copy an expression. This makes a deep copy.
      Specified by:
      copy in class Expression
      Returns:
      the copy of the original expression
    • hasLoopingSubexpression

      public boolean hasLoopingSubexpression(Expression child)
      Given an expression that is an immediate child of this expression, test whether the evaluation of the parent expression causes the child expression to be evaluated repeatedly
      Overrides:
      hasLoopingSubexpression in class Expression
      Parameters:
      child - the immediate subexpression
      Returns:
      true if the child expression is evaluated repeatedly
    • computeSpecialProperties

      public int computeSpecialProperties()
      Determine the special properties of this expression
      Overrides:
      computeSpecialProperties in class Expression
      Returns:
      StaticProperty.NON_CREATIVE.
    • evaluateItem

      public Item evaluateItem(XPathContext context) throws XPathException
      Evaluate the expression to return a singleton value
      Overrides:
      evaluateItem in class Expression
      Parameters:
      context - The context in which the expression is to be evaluated
      Returns:
      the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
      Throws:
      XPathException - if any dynamic error occurs evaluating the expression
    • effectiveBooleanValue

      public boolean effectiveBooleanValue(XPathContext context) throws XPathException
      Get the result as a boolean
      Overrides:
      effectiveBooleanValue in class Expression
      Parameters:
      context - The context in which the expression is to be evaluated
      Returns:
      the effective boolean value
      Throws:
      XPathException - if any dynamic error occurs evaluating the expression
    • getItemType

      public ItemType getItemType(TypeHierarchy th)
      Determine the data type of the items returned by the expression
      Specified by:
      getItemType in class Expression
      Parameters:
      th - the type hierarchy cache
      Returns:
      Type.BOOLEAN
    • toString

      public String toString()
      The toString() method for an expression attempts to give a representation of the expression in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath. In the case of XSLT instructions, the toString() method gives an abstracted view of the syntax
      Overrides:
      toString in class Expression
      Returns:
      a representation of the expression as a string
    • explain

      public void explain(ExpressionPresenter out)
      Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
      Specified by:
      explain in class Expression
      Parameters:
      out - the expression presenter used to display the structure