Class ArithmeticEquation

java.lang.Object
  |
  +--PostfixExpression
        |
        +--ArithmeticEquation

public class ArithmeticEquation

extends PostfixExpression

This class represents an arithmetic equation. For information on the storage method see the constructor and PostfixExpression.setEquation(ExpressionElementStack). For information about how the solution is found, see PostfixExpression.solution().

Fields inherited from class PostfixExpression

expression, TESTING

Constructor Summary

ArithmeticEquation(java.lang.String i)
The calculating for the initialization of this class is fairly complicated.

Methods inherited from class PostfixExpression

infixEquation, setEquation, solution, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ArithmeticEquation

public ArithmeticEquation(java.lang.String i)

The calculating for the initialization of this class is fairly complicated. It recieves a string representing an infix equation which is then parsed using AdaptedStringTokenizer. The delimiters used in the parse are the tokens from ArithmeticOperatorTable and GenericGroupingSymbolTable. The algorithm used then is this:

• create a new stack of expression elements SE
• while(there are more tokens)
• if the current token is an Operator (as determined by the isAnOperator function in OperatorTable)
  push the appropriate Operator onto SE
• else if the current token is a GroupingSymbol (as determined by the GroupingSymbolTable.isAGroupingSymbol(String) function in GroupingSymbolTable)
  push the appropriate GroupingSymbol onto SE
• else if the current token is a Integer (as determined by the parseInt function in Integer)
  push the appropriate Integer onto SE
• else consider the current token to be a Variable
  push the approprate Variable onto SE
• Reverse SE
• Call setEquation of PostfixExpression with SE

After the while loop is through SE now contains all the information that was in the initial string, but all of the information has been identified and pushed into a stack. The only problem is that in the process of pushing it on the stack the order has been reversed, so the ExpressionElementStack.reverse() method is called on SE and SE is sent to the PostfixExpression.setEquation(ExpressionElementStack) of the superclass to be converted and stored in postfix form.

Parameters:

i - string representing an infox arithmetic equation

See Also:

PostfixExpression.setEquation(ExpressionElementStack)