net.sf.saxon.expr
Class MinimaxComparison

java.lang.Object
  extended by net.sf.saxon.expr.ComputedExpression
      extended by net.sf.saxon.expr.BinaryExpression
          extended by net.sf.saxon.expr.MinimaxComparison
All Implemented Interfaces:
Serializable, Expression

public class MinimaxComparison
extends BinaryExpression

Class to handle many-to-many A less-than B comparisons by evaluating min(A) < max(B), and similarly for greater-than, etc. This expression is used only where it is known that the comparisons will all be numeric: that is, where at least one of the operands has a static type that is a numeric sequence.

See Also:
Serialized Form

Field Summary
 
Fields inherited from class net.sf.saxon.expr.BinaryExpression
operands, operator
 
Fields inherited from class net.sf.saxon.expr.ComputedExpression
lineNumber, NO_ARGUMENTS, staticProperties
 
Constructor Summary
MinimaxComparison(Expression p0, int operator, Expression p1)
           
 
Method Summary
 Expression analyze(StaticContext env)
          Type-check the expression.
 boolean effectiveBooleanValue(XPathContext context)
          Evaluate the expression in a boolean context
 Item evaluateItem(XPathContext context)
          Evaluate the expression in a given context
 ItemType getItemType()
          Determine the data type of the expression
 
Methods inherited from class net.sf.saxon.expr.BinaryExpression
computeCardinality, display, displayOperator, equals, getSubExpressions, hashCode, isCommutative, promote, setDetails, simplify
 
Methods inherited from class net.sf.saxon.expr.ComputedExpression
computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, evaluateAsString, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MinimaxComparison

public MinimaxComparison(Expression p0,
                         int operator,
                         Expression p1)
Method Detail

analyze

public Expression analyze(StaticContext env)
                   throws XPathException
Type-check the expression.

Specified by:
analyze in interface Expression
Overrides:
analyze in class BinaryExpression
Parameters:
env - the static context of the expression
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)

getItemType

public ItemType getItemType()
Determine the data type of the expression

Returns:
Type.BOOLEAN

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException
Evaluate the expression in a given context

Specified by:
evaluateItem in interface Expression
Overrides:
evaluateItem in class ComputedExpression
Parameters:
context - the given context for evaluation
Returns:
a BooleanValue representing the result of the numeric comparison of the two operands
Throws:
XPathException - if any dynamic error occurs evaluating the expression

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)
                              throws XPathException
Evaluate the expression in a boolean context

Specified by:
effectiveBooleanValue in interface Expression
Overrides:
effectiveBooleanValue in class ComputedExpression
Parameters:
context - the given context for evaluation
Returns:
a boolean representing the result of the numeric comparison of the two operands
Throws:
XPathException - if any dynamic error occurs evaluating the expression