slogo.expression

Class Variable

java.lang.Object

slogo.GrammarElement

slogo.expression.ArithmeticBase

slogo.expression.Variable

All Implemented Interfaces:

java.lang.Comparable<Variable>

public class Variable
extends ArithmeticBase
implements java.lang.Comparable<Variable>

A variable stores a value and can be used in an expression. Clients can create many objects representing a variable, say "X", but each of these maps to the same object so that there is a common value for any occurrence of a named-variable

See Also:

VariableFactory

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.String	myName

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
Variable(java.lang.String name) Represents a variable

Method Summary

Modifier and Type	Method and Description
int	compareTo(Variable v) Compare the variables by their names.
boolean	equals(java.lang.Object o) Determines equality based on the Variable's name
java.lang.Double	evaluate(Context c) uses the hook/template method value to return a Double
java.lang.String	toString()
java.lang.String	toStringV()
double	value(Context c)

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

myName

private java.lang.String myName

Constructor Detail

Variable

public Variable(java.lang.String name)

Represents a variable

Parameters:

name - - the variable's name, e.g., "X"

Method Detail

value

public double value(Context c)

Specified by:

value in class ArithmeticBase

evaluate

public java.lang.Double evaluate(Context c)

uses the hook/template method value to return a Double

Overrides:

evaluate in class ArithmeticBase

Parameters:

c - the context of the expression--may affect the value

Returns:

the result of evaluating the construct

equals

public boolean equals(java.lang.Object o)

Determines equality based on the Variable's name

Overrides:

equals in class java.lang.Object

compareTo

public int compareTo(Variable v)

Compare the variables by their names.

Specified by:

compareTo in interface java.lang.Comparable<Variable>

toStringV

public java.lang.String toStringV()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object