prefix "forth"

simply.py

class Simply:
    def __init__(self, input):
        self.input = input
    
    def next(self):
        end =  self.input.index(" ")
        token = self.input[:end]
        self.input = self.input[end+1:]
        return token

    def one(self):
        token = self.next()
        return self.eval(token)
    
    def eval(self, token):
       f =  d[token]
       return f(self) 

d = {
    "add": lambda s: s.one() + s.one(),
    "mult": lambda s:  s.one() * s.one(), 
    "print": lambda s: print(s.one()),
    "int":  lambda s: int(s.next()),
}

s = Simply('''print mult int 2 add int 3 int 5 ''')

s.one()