def main():
    stack = []
    state = 0x00
    ds = [] # data stack
    ss = [] # string stack
    es = [] # escape stack
    for ch in read_file("test.json").strip():
        cat = catcode[min(ord(ch), 0x7E)]
        state = parse_ch(cat, ch, stack, state, ds, ss, es)
    state = parse_ch(0, u'', stack, state, ds, ss, es)
    if state != 0x00:
        raise Exception("JSON decode error: truncated")
    if len(ds) != 1:
        raise Exception("JSON decode error: too many objects")
    val = ds.pop()
    print val

def parse_ch(cat, ch, stack, state, ds, ss, es):
    while True:
        code = states[state][cat]
        action = code >> 8 & 0xFF
        code   = code      & 0xFF
        if action == 0xFF: # reduce
            if code == 0xFF:
                raise Exception("JSON decode error: syntax")
            state = stack.pop()
            action = code
            if action > 0:
                do_action(action, ch, ds, ss, es)
        else:
            if action >= 0x80: # shift
                stack.append(gotos[state])
                action -= 0x80
            if code != 0xFF: # nop
                state = code
            if action > 0:
                do_action(action, ch, ds, ss, es)
            break
    return state

def do_action(action, ch, ds, ss, es):
    if action == 0x1:
        ds.append([])
    elif action == 0x2:
        ds.append({})
    elif action == 0x3:
        val = ds.pop()
        ds[len(ds)-1].append(val)
    elif action == 0x4:
        val = ds.pop()
        key = ds.pop()
        ds[len(ds)-1][key] = val
    elif action == 0x10:
        ds.append(None)
    elif action == 0x20:
        ds.append(True)
    elif action == 0x30:
        ds.append(False)
    elif action == 0x40:
        val = u"".join(ss)
        ds.append(val)
        ss[:] = []
        es[:] = []
    elif action == 0x50:
        val = int(u"".join(ss))
        ds.append(val)
        ss[:] = []
    elif action == 0x60:
        val = float(u"".join(ss))
        ds.append(val)
        ss[:] = []
    elif action == 0xA:
        ss.append(ch)
    elif action == 0xB:
        es.append(ch)
    elif action == 0xC:
        ss.append(unichr(escape_characters[ch]))
    elif action == 0xD:
        ss.append(unichr(int(u"".join(es), 16)))
        es[:] = []
    else:
        assert False, "JSON decoder bug"

def read_file(filename):
    with open(filename, "rb") as fd:
        return fd.read().decode('utf-8''b': 8, 't': 9, 'n': 10, 'f': 12, 'r': 13}


if __name__=="__main__":
    main()