acalejos / CS560Project

A simple Python-to-Scala transpiler

A Simple Python-to-Scala Transpiler

You should have Python 3.5+ as your default python in your command line environment.

You can use sbt test to run all the tests inside our project.

You can also use the project as a command-line tool. Usage (either way is fine):

• sbt "run <inputFile>.py", the output filename will be <inputFile>.scala
• sbt "run (--input-file | -i) <inputFile>.py (--output-file | -o) <outputFile>"

Example by running sbt "run test/quicksort.py":

Python

def quicksort(a: List[int]) -> List[int]:
    if len(a) < 2:
        return a
    else:
        pivot = a[len(a) // 2]
        return quicksort([_ for _ in a if pivot > _]) + \
            [_ for _ in a if pivot == _] + \
            quicksort([_ for _ in a if pivot < _])


quicksort([10, 6, 8, 1, 0, 9]) == [0, 1, 6, 8, 9, 10]

Scala

def quicksort(a: List[Int]): List[Int] = {
  if (a.length < 2) {
    a
  } else {
    var pivot = a(a.length / 2)
    quicksort(a.filter(pivot > (_))) ++ a.filter(pivot == (_)) ++ quicksort(a.filter(pivot < (_)))
  }
}
quicksort(List(10, 6, 8, 1, 0, 9)) == List(0, 1, 6, 8, 9, 10)

Currently, our project supports the following features of Python:

• Arithmetic/Boolean expressions
• Variable assignments
• if/for statements
• Function definitions/calls
• List operations
• List comprehension

Notice:

• Parameters of a function declaration have to be explicitly typed
• A single variable cannot be assigned to values with different types