com.icl.saxon.expr
Class SingletonComparison
java.lang.Object
|
+--com.icl.saxon.expr.Expression
|
+--com.icl.saxon.expr.SingletonComparison
- public class SingletonComparison
- extends Expression
Singleton Comparison: A Relational Expression that compares a singleton node-set with a string
or numeric value for equals, not-equals, greater-than or less-than.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
SingletonComparison
public SingletonComparison(SingletonExpression p1,
int op,
Value p2)
simplify
public Expression simplify()
throws org.xml.sax.SAXException
- Simplify an expression
- Overrides:
simplify
in class Expression
- Returns:
- the simplified expression
evaluate
public Value evaluate(Context c)
throws org.xml.sax.SAXException
- Evaluate the expression in a given context
- Overrides:
evaluate
in class Expression
- Parameters:
c
- the given context for evaluation- Returns:
- a BooleanValue representing the result of the comparison of the two operands
evaluateAsBoolean
public boolean evaluateAsBoolean(Context c)
throws org.xml.sax.SAXException
- Evaluate the expression in a given context
- Overrides:
evaluateAsBoolean
in class Expression
- Parameters:
c
- the given context for evaluation- Returns:
- a boolean representing the result of the numeric comparison of the two operands
getDataType
public int getDataType()
- Determine the data type of the expression, if possible
- Overrides:
getDataType
in class Expression
- Returns:
- Value.BOOLEAN
getDependencies
public int getDependencies()
- Determine which aspects of the context the expression depends on. The result is
a bitwise-or'ed value composed from constants such as Context.VARIABLES and
Context.CURRENT_NODE
- Overrides:
getDependencies
in class Expression
reduce
public Expression reduce(int dependencies,
Context context)
throws org.xml.sax.SAXException
- Perform a partial evaluation of the expression, by eliminating specified dependencies
on the context.
- Overrides:
reduce
in class Expression
- Parameters:
dependencies
- The dependencies to be removedcontext
- The context to be used for the partial evaluation- Returns:
- a new expression that does not have any of the specified
dependencies
toString
public java.lang.String toString()
- Display the expression as a string
- Overrides:
toString
in class java.lang.Object