Add basic applications (calculator)

[leo-aa88]

[vinsdragonis]

Proposal

4 functions to perform simple arithmetic calculations

Proposed changes

• add(x, y)
• sub(x, y)
• mul(x, y)
• div(x, y)

Files changed

• /include/math.h
• /src/math.c

Pull requests have been generated for the 2 files. Please do have a look.

[leo-aa88]

The basic arithmetic calculations given by the command line will be parsed in a manner similar to how printf handles a variable number of arguments. For example, an expression like:
1+2*3-5
Will have the tokens +, * and - as well as the numbers parsed into the required operations.
Therefore, I am closing this pull request.