🐍 I made my own version of Python in C! 🐍 + ⓒ

You know those "Python interpreters" which are really just eval(input()) (or exec(input()))? Well, I decided to make the polar opposite of that — a ground-up custom implementation of Python in C with nothing more than standard libc. 1191 semicolons and 2252 lines later, I've gotten my interpreter to a usable state.

A quick disclaimer: this isn't finished yet! I'm sharing it now since it's in a usable state, but it doesn't (yet) implement things like OOP, dictionaries or arrays. I'll share updates when I make them!

Changes

Of course, what fun would an exact remake be? To shake things up a bit, I've made some changes:

Function calls don't have parens. So function 1, 2, 3 is like function (1, 2, 3) in normal Python. This means that something like (int x + 1) is saying int (x + 1), so be careful with your parentheses! (If you intend that to not happen, do (int x) + 1.)
For a function call with no arguments, use () as the argument. (() is actually a synonym for None.)

Arguments are handled with my. This means that instead of doing:

def myfun(x, y, z):


You do:
```Python
def myfun:
  my x
  my y
  my z
  <actions>

Now, what point does this have you ask? Well, you can put the my statement anywhere. Inside loops, conditionals, you name it. So you could do:


def myfun: 
  i = 1
  while i < 10:
    my x
    print "The #" + (str i) + " argument is: " + (str x)
    i = i + 1

Limitations

No for loops. For loops require iterators, which don't exist yet.
No % or +=, -=, etc.
No elif — use else & if, and no break/continue
No True or False — use 1 and 0
No float

So yeah, it's limited as of now, but it works!

Demo

Here's a demo (look in source.fpy in the repl for more):


def fib:
  my x
  if x < 3:
    return 1
  return (fib x-1) + (fib x-2)

def factorial:
  my x
  if x == 1:
    return x
  return x * (factorial x-1)

userExiting = 0
while userExiting == 0:
  print "Welcome to the calculator!  What would you like to do?\n\
1 - Exit\n\
2 - Calculate factorial\n\
3 - Calculate fibonacci"
  userInput = input ">> "
  if userInput != "1" and userInput != "2" and userInput != "3":
    print "Invalid option!  Try again."
  else:
    userInput = int userInput
    if userInput == 1:
      userExiting = 1
    if userInput == 2:
      userInput = int (input "What number? ")
      print "Factorial of " + (str userInput) + " is " + (str (factorial userInput))
    if userInput == 3:
      userInput = int (input "What number? ")
      print "The #" + (str userInput) + " fibonacci number is " + (str (fib userInput))

How can I get started?

Just fork the repl and edit source.fpy (a demo program is preloaded)! Hit run and you'll be good to go!

I hope you enjoy! There's probably numerous bugs (if you find one please report it!) but so far it's worked fairly well!

Note: It's been asked if the build folder was auto-generated. The answer is no — I wrote all the code in this project! I simply put code in the build folder to make the repl easier to navigate.

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