com.trassare.calculator.engine
Class InfixCalculator

java.lang.Object
  com.trassare.calculator.engine.InfixCalculator

public class InfixCalculator
extends Object

InfixCalculator parses, calculates, and prints the results of a series of floating-point arithmetic expressions, one to a line, as given by the following grammar:

command -> { expression { ! | >> Identifier } } \n
expression -> term { + term | - term }
term -> { * power | / power }
power -> factor [ ^ power ] | { - } { ln | sin | cos | tan | asin | acos | atan}? power
factor -> ( expression ) | -factor | Number | @

Historical stuff (the origins of this application): CS 152, Fall, 2005
Programming Assignment #1
Due: October 11, 2005
Class: Section 1, TTh 0900-1015

Version:

2 September 2006

Author:

Samuel Trassare

Constructor Summary

InfixCalculator(ExpressionScanner inS)
Construct a new InfixCalculator class using the ExpressionScanner provided by Doctor Kenneth Louden.

Method Summary

BigDecimal	go() Begin execution of the InfixCalculator.
void	resetScanner(PushbackReader instream) Supply the calculator with a new input stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

InfixCalculator

public InfixCalculator(ExpressionScanner inS)

Construct a new InfixCalculator class using the ExpressionScanner provided by Doctor Kenneth Louden.

Parameters:

inS - the new ExpressionScanner.

Method Detail

go

public final BigDecimal go()
                    throws ParseException

Begin execution of the InfixCalculator.

Returns:

the completely evaulated expression.

Throws:

ParseException - in any error condition a ParseException is thrown

resetScanner

public final void resetScanner(PushbackReader instream)

Supply the calculator with a new input stream. This function is necessary if input is delivered via a StringReader wrapped in the PushbackReader. Unfortunately StringReaders don't have a "rewind" capability so instead, supply a new input. This method calls it's evil twin in ExpressionScanner.

Parameters:

instream - the new PushbackReader to read from.