: Class SingletonComparison
com.icl.saxon.expr
Class SingletonComparison
java.lang.Object
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+--com.icl.saxon.expr.Expression
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+--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 com.icl.saxon.expr.Expression
containsReferences , enumerate , evaluateAsNodeSet , evaluateAsNumber , evaluateAsString , getStaticContext , indent , isContextDocumentNodeSet , make , outputStringValue , setStaticContext , usesCurrent
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
SingletonComparison
public SingletonComparison (SingletonExpression p1,
int op,
Value p2)
simplify
public Expression simplify ()
throws XPathException
Simplify an expression
Overrides: simplify
in class Expression
Returns: the simplified expression
evaluate
public Value evaluate (Context c)
throws XPathException
Evaluate the expression in a given context
Overrides: evaluate
in class Expression
Parameters: c
- the given context for evaluationReturns: a BooleanValue representing the result of the comparison of the two operands
evaluateAsBoolean
public boolean evaluateAsBoolean (Context c)
throws XPathException
Evaluate the expression in a given context
Overrides: evaluateAsBoolean
in class Expression
Parameters: c
- the given context for evaluationReturns: 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 XPathException
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 evaluationReturns: a new expression that does not have any of the specified
dependencies
display
public void display (int level)
Diagnostic print of expression structure
Overrides: display
in class Expression