net.sf.saxon.expr
Class BooleanExpression
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.BinaryExpression
net.sf.saxon.expr.BooleanExpression
- All Implemented Interfaces:
- Serializable, Expression
class BooleanExpression
- extends BinaryExpression
Boolean expression: two truth values combined using AND or OR.
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, evaluateAsString, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError |
BooleanExpression
public BooleanExpression(Expression p1,
int operator,
Expression p2)
analyze
public Expression analyze(StaticContext env)
throws XPathException
- Type-check the expression. Default implementation for binary operators that accept
any kind of operand
- 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)
evaluateItem
public Item evaluateItem(XPathContext context)
throws XPathException
- Evaluate the expression
- Specified by:
evaluateItem
in interface Expression
- Overrides:
evaluateItem
in class ComputedExpression
- 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 c)
throws XPathException
- Evaluate as a boolean.
- Specified by:
effectiveBooleanValue
in interface Expression
- Overrides:
effectiveBooleanValue
in class ComputedExpression
- Parameters:
c
- 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()
- Determine the data type of the expression
- Returns:
- Type.BOOLEAN