Class Evaluator

java.lang.Object
net.sf.saxon.expr.parser.Evaluator
Direct Known Subclasses:
Evaluator.EagerSequence, Evaluator.EmptySequenceEvaluator, Evaluator.LazySequence, Evaluator.LazyTail, Evaluator.Literal, Evaluator.MakeIndexedVariable, Evaluator.MemoClosureEvaluator, Evaluator.OptionalItem, Evaluator.Process, Evaluator.SharedAppend, Evaluator.SingleItem, Evaluator.SingletonClosure, Evaluator.StreamingArgument, Evaluator.SuppliedParameter, Evaluator.Variable
public abstract class Evaluator extends Object
An Evaluator evaluates an expression to return a sequence

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static final class 
    Evaluator.EagerSequence
    An evaluator for arguments that in general return a sequence, where the sequence is evaluated eagerly.
    static final class 
    Evaluator.EmptySequenceEvaluator
    An evaluator that always returns the empty sequence
    static final class 
    Evaluator.LazySequence
    An evaluator for arguments that in general return a sequence, where the sequence is evaluated lazily on first use.
    static final class 
    Evaluator.LazyTail
    An evaluator for arguments that in general return a sequence, where the sequence is evaluated lazily on first use.
    static final class 
    Evaluator.Literal
    An evaluator for arguments supplied as a literal
    static final class 
    Evaluator.MakeIndexedVariable
    An evaluator for an expression that makes use of an indexed variable
    static final class 
    Evaluator.MemoClosureEvaluator
    An evaluator for arguments that in general return a sequence, where the sequence is evaluated lazily on first use, and where the value might be needed more than once.
    static final class 
    Evaluator.OptionalItem
    A (default) evaluator for arguments supplied as an expression that will return either a singleton item, or an empty sequence
    static final class 
    Evaluator.Process
    A push-mode evaluator for an expression
    static final class 
    Evaluator.SharedAppend
    An evaluator for "shared append" expressions: used when the argument to a function is a block potentially containing a recursive call.
    static final class 
    Evaluator.SingleItem
    A (default) evaluator for arguments supplied as an expression that will always return a singleton item
    static final class 
    Evaluator.SingletonClosure
    An evaluator for arguments that in general return a sequence, where the sequence is evaluated lazily on first use, and where the value might be needed more than once.
    static final class 
    Evaluator.StreamingArgument
    An evaluator for the first (streamed) argument of a streamable function call.
    static final class 
    Evaluator.SuppliedParameter
    An evaluator for a reference to an external parameter value
    static final class 
    Evaluator.Variable
    An evaluator for arguments supplied as a variable reference

  • Constructor Summary

    Constructors
    Constructor
    Description
    Evaluator()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    abstract Sequence
    evaluate(Expression expr, XPathContext context)
    Evaluate an expression to return a sequence
    abstract int
    getCode()
    Get the integer code for the evaluator

    Methods inherited from class Object

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

  • Constructor Details

    • Evaluator

      public Evaluator()

  • Method Details

    • getCode

      public abstract int getCode()
      Get the integer code for the evaluator
      Returns:
      the integer code for the evaluator

    • evaluate

      public abstract Sequence evaluate(Expression expr, XPathContext context) throws XPathException
      Evaluate an expression to return a sequence
      Parameters:
      expr - the expression to be evaluated
      context - the dynamic context for evaluation
      Returns:
      the result of the evaluation
      Throws:
      XPathException - if any dynamic error occurs during the evaluation