A small command line calculator built on scala which accepts operations in Reverse Polish Notation.
Someone posted the equivalent version of this in Ruby, and asked anyone who was up for the challenge to produce their own using a language of their choice. Since I'm not the kind of person to let an opportunity to code in Scala go by, I sat down and wrote this out after brushing up on my parser combinators.
To run this, you'll need scala and sbt installed, which on OSX is as simple as:
brew install scala sbt
Then, from the project directory, run sbt assembly to produce the executable jar, and finally, to use the calculator:
java -jar ./target/scala-2.XX/RPNCalculator-assembly-X.X.jar "3 4 - 5 + 2 *"
Alternatively you can use sbt "run \"3 4 - 5 + 2 *\"", to compile and run the code directly using your scala installation.
Of course, you can put whatever expression you want as the argument, but the above is a simple example.