nz.org.venice.parser.expression
Class ComparisionExpression

java.lang.Object
  nz.org.venice.parser.expression.AbstractExpression
      nz.org.venice.parser.expression.BinaryExpression
          nz.org.venice.parser.expression.ComparisionExpression

All Implemented Interfaces:

java.lang.Cloneable, Expression

Direct Known Subclasses:

EqualThanExpression, GreaterThanEqualExpression, GreaterThanExpression, LessThanEqualExpression, LessThanExpression, NotEqualExpression

public abstract class ComparisionExpression

extends BinaryExpression

Abstract base class for the comparision expressions: >, <, ==, !=, <=, >=

Field Summary

Fields inherited from interface nz.org.venice.parser.Expression

BOOLEAN_TYPE, FALSE, FLOAT_QUOTE_TYPE, FLOAT_TYPE, INTEGER_QUOTE_TYPE, INTEGER_SHORT_TYPE, INTEGER_TYPE, NUMERIC_TYPE, STRING_TYPE, TRUE, TRUE_LEVEL, UNDEFINED_TYPE

Constructor Summary

ComparisionExpression(Expression left, Expression right)
Create a new comparision expression with the given left and right arguments.

Method Summary

int	checkType() Check the input arguments to the expression.
int	getType() Get the type of the expression.
Expression	simplify() Perform simplifications and optimisations on the expression tree.

Methods inherited from class nz.org.venice.parser.expression.BinaryExpression

getChildCount, toString

Methods inherited from class nz.org.venice.parser.expression.AbstractExpression

clone, equals, getChild, getId, getIndex, getNumberFormat, getParent, getParseMetadata, hashCode, isRoot, iterator, parseDouble, parseInt, printParents, setChild, setChildMutableVersion, setParent, setParseMetadata, simplifyMutableVersion, size, size, toString, validTree, valueOfDouble, valueOfInt

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface nz.org.venice.parser.Expression

evaluate

Constructor Detail

ComparisionExpression

public ComparisionExpression(Expression left,
                             Expression right)

Create a new comparision expression with the given left and right arguments.

Method Detail

checkType

public int checkType()
              throws TypeMismatchException

Check the input arguments to the expression. They can only be Expression.INTEGER_TYPE or Expression.FLOAT_TYPE. Both must be the same!

Returns:

the type of the expression

Throws:

TypeMismatchException - if the expression has incorrect types

simplify

public Expression simplify()

Description copied from class: AbstractExpression

Perform simplifications and optimisations on the expression tree. For example, if the expression tree was a and true then the expression tree would be simplified to a.

Specified by:

simplify in interface Expression

Overrides:

simplify in class AbstractExpression

getType

public int getType()

Get the type of the expression.

Returns:

Expression.BOOLEAN_TYPE.