A small program to teach myself Haskell. It reads a simple expression from the command line and evaluates it.

Haskell Stack version 1.9 or later is needed to build the project.
Run stack setup in the repo to install and configure the correct Haskell compiler.

Run stack run -- '1 + 1' to try it. You can insert any expression, whitespaces are automatically ignored.

Run stack install, it will install the calc executable in your PATH.

Here is a list of supported expressions. Unmarked lines are not yet implemented.

• the four basic operations +, -, *, /
• nested expressions with parenthesis (1 + 2) * 3
• power 2^2
• power with exponent expression 2^(3-2)
• square root sqrt(4)
• percentage operations 100 - 20%