reecocho / math-parser

A simple mathematical expression parser written in C.

Math Parser

Math Parser is a small little mathematical expression parser I wrote in C to test my language skills. It uses no external libraries other than the standard C library. The parser works in two stages. Lexical analysis and parsing. The lexical analysis stage reads the user's input and breaks it up into a set of tokens. These tokens contain a type (Number, addition, subtraction...) and in the case of a number, a string containing their value. These tokens are fed into the parser. The parser takes the tokens and converts them into reverse polish notation using the shunting yard algorithm. These new tokens are fed into the final parser which evaluates the expressions and spits out the results.

Building

CMake is used for the build system, but you could just as easily compile it directly from the command line since there aren't many files.

Usage

After executing the program in the command line, you can enter any standard mathematical expression. For example 11 + (5 - 6) / - 2. Would result in the output, 11.5. supported features are listed below.

Features

1. Real number Ex. 1.0
2. Addition (+)
3. Subtraction (-)
4. Multiplication (*)
5. Division (/)
6. Negation Ex. -1.0
7. Exponentiation (^)
8. Variables Ex. x = 3.14159 * 4^2

Planned Features

A list of planned features is given below.

1. Standard functions
2. Custom functions
3. Comparisons