This is the final project for COP3503 (programming fundamentals for CS majors II). The purpose of this project was to build a "symbolic calculator" that can support rationals and irrational numbers symbolically. It can simplify fractions and expressions with roots.
- ( 1 - -2 / 3 ) ^ ( 2 rt 16 )
- -54 ^ ( 1 / 3 )
- 3 rt ( -4 + 1 / 2 )
- 1 / ( 2 rt 2 ) + 2 rt 2 / 2
- 3 rt 49 * 3 rt 7
- The strategy for implementing the calculator program was to use polymorphism and recursion
Expresionis the abstract base class other classes are derived from. Objects of types derived from this class represent the mathematical expression in memory.
The derived classes are:Integerfor representing integers.Divisionfor representing rationals and unsimplified division expressions.Exponentiationfor expresenting irrational numbers (roots) and unsimplified exponentiation expressions.Multiplicationfor representing "non-primitive" multiplication expression.Additionfor representing "non-primitive" addition expression.
- Each object of the above types holds 2 pointers of type
Expression*to other expression objects (theIntegerclass is an exception). That way, after the input is tokenized, an expression tree is constructed for each expression entered by the user. - The most important member fuction of each derived class is
virtual Expression* simplify(), which each class uses to simplify its expression.simplify()of one class (almost always) calls asimply()of another class. That way, the whole expression tree can be simplified recursively.
While this implementation did meet the specs set by the professor of the class, more work needs to be done to ensure a more elegant and correct implementation to this "symbolic calculator" project:
- Implement the tokenizer using regex so that the user won't need to enter a space between each two consecutive tokens.
- Clean up the design and improve code quality
- Deal with memory leaks issues (perhaps consider using smart pointers)