Splits

Splits is an esoteric programming language invented by Dr Laurie Tratt in 2024.

Overview

The language uses reverse polish notation and supports literal integers, as well as operators +, -, * and comparison >=.

Every line is either a variable assignment, or a while loop start or end. While loop starts with while condition where condition is an expression evaluating to 1 or 0. While loop ends with keyword end.

Examples

Factorial

This program computes the factorial of number 5.

n = 5
r = 1
while n 1 >=
  r = r n *
  n = n 1 -
end

Implementation

Implementation in Python provided by the author.

import sys
class Ev:
  def ev(self, s):
    self.vars = {}
    lines = [x for x in s.split("\n") if x.strip() != ""]
    pc = 0
    while pc < len(lines):
      line = lines[pc]
      match line.split(maxsplit=1)[0]:
        case 'while':
          if self.ev_expr(line.split(maxsplit=1)[1]) == 1: pc += 1
          else:
            while lines[pc].split(maxsplit=1)[0] != 'end': pc += 1
            pc += 1
        case 'end':
          while lines[pc].split(maxsplit=1)[0] != 'while': pc -= 1
        case _:
          (name, _, expr) = line.split(maxsplit=2)
          self.vars[name] = self.ev_expr(expr)
          pc += 1
    print(self.vars)
  def ev_expr(self, s):
    toks = s.split()
    stack = []
    for tok in toks:
      if tok.isdigit(): stack.append(int(tok))
      elif tok in self.vars: stack.append(self.vars[tok])
      else:
        rhs = stack.pop()
        lhs = stack.pop()
        if tok == "+": stack.append(lhs + rhs)
        elif tok == "*": stack.append(lhs * rhs)
        elif tok == "-": stack.append(lhs - rhs)
        elif tok == ">=":
          if lhs >= rhs: stack.append(1)
          else: stack.append(0)
    return stack[0]
Ev().ev(open(sys.argv[1]).read())