slogo.expression

Class Subroutine

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.expression.Subroutine

All Implemented Interfaces:

java.lang.Comparable<Subroutine>

public class Subroutine
extends Instruction
implements java.lang.Comparable<Subroutine>

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:

SubroutineFactory

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
Subroutine(java.lang.String name) Represents a subroutine

Method Summary

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

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

Subroutine

public Subroutine(java.lang.String name)

Represents a subroutine

Parameters:

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

Method Detail

evaluate

public java.lang.Object evaluate(Context c)

uses the hook/template method value to return a Double

Specified by:

evaluate in class Instruction

Parameters:

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

Returns:

the value we evaluate as a double

equals

public boolean equals(java.lang.Object o)

Determines equality based on the Variable's name

Overrides:

equals in class java.lang.Object

Parameters:

o - is the object we are using in the boolean comparison

Returns:

whether the comparison is true or false

compareTo

public int compareTo(Subroutine v)

Compare the variables by their names.

Specified by:

compareTo in interface java.lang.Comparable<Subroutine>

Parameters:

v - is the variable we are using in the comparison

Returns:

the result of the comparison

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object