This is a re-work of the parser included in the SKWEEK project (https://github.com/rburgosnavas/SKWEEK). I'm attempting to make a better implementation by better design and refactoring.

Anyone who comes across this project and wants to lend a hand, feel free to do so!

The parser is now split into three different classes:

• Lexer splits a String of an expression into a List of Symbols;
• Evaluator basically takes a List of Symbols and returns a new List of Symbols converted to postfix;
• Interpreter interprets this List and returns the result

The old README below explains the general purpose of the parser. The Parser class was responsible for splitting to tokens, converting to postfix, and calculating the postfix expression and returning the result. These responsibilities are now divided by the three main classes listed above. As I'm still learning from this project, and as I expect bugs to creep out, I'm leaving the Parser class in the project for now. I feel that Parser works fairly well by itself so it won't hurt. For more info about Parser, read the old README below.

To amend the lack documentation, a Runner class is included to show how the Parser works, as well as the interaction between Lexer, Evaluator, and Interpreter. I do plan to fully document everything once I know everything works well.

This parser is more or less a version of a standard math expression parser. It is used in the SKWEEK app, which takes a math-like expression and turns it into 8-bit sound sequence (what's knows as bytebeat). The parser is capable of handling variables internally hardwired to "t", "x", "y", and "z". A client can build an instance of Parser with the choice of passing values that correspond to this variables.

Internally, the Parser class splits a String of the expression and splits it into a list of "symbols". This list is then processed to be converted to "postfix" list of these symbols, and finally, the "postfix" list is read and calculated into the final result.