com.icl.saxon.expr

Class RelationalExpression

final class RelationalExpression extends BinaryExpression

Relational Expression: a boolean expression that compares two expressions for equals, not-equals, greater-than or less-than.
Constructor Summary
RelationalExpression()
Default constructor
RelationalExpression(Expression p1, int op, Expression p2)
Create a relational expression identifying the two operands and the operator
Method Summary
Valueevaluate(Context c)
Evaluate the expression in a given context
booleanevaluateAsBoolean(Context c)
Evaluate the expression in a given context
intgetDataType()
Determine the data type of the expression
Expressionreduce(int dependencies, Context context)
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Expressionsimplify()
Simplify an expression

Constructor Detail

RelationalExpression

public RelationalExpression()
Default constructor

RelationalExpression

public RelationalExpression(Expression p1, int op, Expression p2)
Create a relational expression identifying the two operands and the operator

Parameters: p1 the left-hand operand op the operator, as a token returned by the Tokenizer (e.g. Tokenizer.LT) p2 the right-hand operand

Method Detail

evaluate

public Value evaluate(Context c)
Evaluate the expression in a given context

Parameters: c the given context for evaluation

Returns: a BooleanValue representing the result of the numeric comparison of the two operands

evaluateAsBoolean

public boolean evaluateAsBoolean(Context c)
Evaluate the expression in a given context

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

Returns: Value.BOOLEAN

reduce

public Expression reduce(int dependencies, Context context)
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Parameters: dependencies The dependencies to be removed context The context to be used for the partial evaluation

Returns: a new expression that does not have any of the specified dependencies

simplify

public Expression simplify()
Simplify an expression

Returns: the simplified expression