nz.org.venice.parser.expression
Class AlertExpression

java.lang.Object
  nz.org.venice.parser.expression.AbstractExpression
      nz.org.venice.parser.expression.UnaryExpression
          nz.org.venice.parser.expression.AlertExpression

All Implemented Interfaces:

java.lang.Cloneable, Expression

Direct Known Subclasses:

HaltExpression

public class AlertExpression

extends UnaryExpression

An no op expression which when evaluated displays a message. For debugging rules.

Author:

Mark Hummel

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

AlertExpression(Expression arg, Expression[] optionalArgs)
Create a new alert expression.

Method Summary

int	checkType() Check the argument to the expression.
java.lang.Object	clone()
double	evaluate(Variables variables, QuoteBundle quoteBundle, Symbol symbol, int day) Evaluate the expression and subexpressions, and then display the resulting message.
Expression	getChild(int child) Return the child of this node at the given index.
int	getChildCount() Return the number of children required in an alert expression.
int	getType() Get the type of the expression
java.lang.String	toString() Return a string representing the expression contents.

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

AlertExpression

public AlertExpression(Expression arg,
                       Expression[] optionalArgs)

Create a new alert expression.

Parameters:

arg - The message expression

optionalArgs - Optional expressions (max 4) which are appended to the message defined in arg.

Method Detail

evaluate

public double evaluate(Variables variables,
                       QuoteBundle quoteBundle,
                       Symbol symbol,
                       int day)
                throws EvaluationException

Evaluate the expression and subexpressions, and then display the resulting message.

Parameters:

variables - The variables of the rule

quoteBundle - The quote bundle containing the symbol data

symbol - The implicit symbol of the rule

day - The date offset used to evaluate the rule.

Returns:

0.0

Throws:

EvaluationException - if the expression performs an illegal operation such as divide by zero.

checkType

public int checkType()
              throws TypeMismatchException

Check the argument to the expression. It can be an expression.

Returns:

the type of the expression

Throws:

TypeMismatchException - if the expression has incorrect types

toString

public java.lang.String toString()

Return a string representing the expression contents.

Specified by:

toString in interface Expression

Overrides:

toString in class AbstractExpression

Returns:

a string

getType

public int getType()

Get the type of the expression

Returns:

Expression.FLOAT_TYPE

getChildCount

public int getChildCount()

Return the number of children required in an alert expression. This will be a minimum of 1 and a maximum of 4.

Specified by:

getChildCount in interface Expression

Overrides:

getChildCount in class UnaryExpression

Returns:

The number of non null arguments.

getChild

public Expression getChild(int child)

Return the child of this node at the given index.

Specified by:

getChild in interface Expression

Overrides:

getChild in class AbstractExpression

Returns:

child at given index.

clone

public java.lang.Object clone()

Specified by:

clone in interface Expression

Specified by:

clone in class AbstractExpression