Crude MIU System Simulator

miu.py

#!/usr/bin/python -tt

import sys

def rule1(s):
    if s[-1:] == 'i':
        return [s + 'u']
    return [s]

def rule2(s):
    if s[0:1] == 'm':
        return ['m' + s[1:] + s[1:]]
    return [s]

def rule3(s):
    stack = ''
    results = [s]
    for i,c in enumerate(s):
        stack = stack + c
        if stack[-3:] == 'iii':
            results.append(s[:i-2] + 'u' + s[i+1:])
    return results

def rule4(s):
    stack = ''
    results = [s]
    for i,c in enumerate(s):
        stack = stack + c
        if stack[-2:] == 'uu':
            results.append(s[:i-1] + s[i+1:])
    return results


def main():

    rules = [rule1, rule2, rule3, rule4]
    ours = set(['mi'])
    
    while True:
        initial_size = len(ours)
        for r in rules:
            new = [r(x) for x in ours]
            for n in new:
                [ours.add(x) for x in n]
                for x in n:
                    if len(x) <= 4:
                        print(x)
                if 'mu' in n:
                    print('generated mu')
                    break

if __name__ == '__main__':
    sys.exit(main())