Class OperatorTable

java.lang.Object
  |
  +--OperatorTable

Direct Known Subclasses:

ArithmeticOperatorTable

public class OperatorTable

extends java.lang.Object

Much like GroupingSymbolTable this call serves as a holder for a set of other objects and acts as an interface to allow use of them. In this case the objects are Operators.

The most common usage of OperatorTable is ArithmeticOperatorTable.

Field Summary

protected int	capacity The current maximum number of elements possible
protected Operator[]	operators The elements contained in the table
protected int	size The current number of elements

Constructor Summary

OperatorTable()
Creates a new empty table with a capacity of 20 elements

OperatorTable(int i)
Creates a new empty table with a capacity of i elements.

Method Summary

void	add(Operator o) Adds an Operator to the table.
java.lang.String[]	getTokens()
boolean	isAnOperator(java.lang.String token, boolean preceededByAnOperand) Identifies String token as being an {@ Operator} in the table or not based on the context given by preceededByAnOperand.
Operator	operatorFor(java.lang.String token, boolean preceededByAnOperand) Identifies String token and returns the appropriate Operator.

Methods inherited from class java.lang.Object

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

Field Detail

capacity

protected int capacity

The current maximum number of elements possible

size

protected int size

The current number of elements

operators

protected Operator[] operators

The elements contained in the table

Constructor Detail

OperatorTable

public OperatorTable()

Creates a new empty table with a capacity of 20 elements

OperatorTable

public OperatorTable(int i)

Creates a new empty table with a capacity of i elements. If i is 0 then the capacity is set to 1.

Method Detail

add

public void add(Operator o)

Adds an Operator to the table. If there is not room in the table for the symbol then (in the fashion of Vector) the capacity is doubled thereby making space.

Parameters:

o - symbol to be added

isAnOperator

public boolean isAnOperator(java.lang.String token,
                            boolean preceededByAnOperand)

Identifies String token as being an {@ Operator} in the table or not based on the context given by preceededByAnOperand.

Parameters:

token - String to be identified

Returns:

true if token is in the table

operatorFor

public Operator operatorFor(java.lang.String token,
                            boolean preceededByAnOperand)

Identifies String token and returns the appropriate Operator. If token is not in the table then a NotATableElementExcepetion will be thrown (once I get that running.)

Parameters:

token - String to be identified

Returns:

the Operator for token.

getTokens

public java.lang.String[] getTokens()

Returns:

a String array contianing the tokens for the Operators in the table.