macro.py

#!/usr/bin/python3

import turtle

PENUP = "u"
PENDOWN = "d"
FORWARD = "f"
BACKWARD = "b"
LEFT = "l"
RIGHT = "r"
HOME = "h"

def r_arg(dic: dict, sub: str) -> tuple:
    n = 1

    for c in range(len(sub)):
        char = sub[c]

        if char == " ":
            n += 1
            break

        elif char in dic.keys():
            n += 1
            break

        elif not char.isdecimal():
            print("[FATAL] Bad char")
            exit(-1)

        n += 1

    return int(sub[:n-1]), n

def parse_str(s: str, o: object) -> list:
    """
    s: str
    returns a list fot which:
        ret[0] -> returns the method to call
        ret[x] -> argument for the function
    """

    r = []

    # sanity checks

    assert isinstance(s, str), "[FATAL] The argument is not a string !"

    assert len(s) > 0, "[FATAL] The argument is null"

    dic_cmd = {
        PENUP : o.penup,
        PENDOWN : o.pendown,
        FORWARD : o.forward,
        BACKWARD : o.backward,
        LEFT : o.left,
        RIGHT : o.right,
        HOME : o.home
    }

    i = 0

    while i+1 < len(s):

        # Is it a blank char
        if s[i] == " ":
            i += 1
            continue
        elif s[i] not in dic_cmd.keys():
            print("[FATAL] Bad char in the string")
            exit(-1)

        current = s[i]
        # current character

        if current == PENUP:
            r.append([dic_cmd[PENUP]])
        elif current == PENDOWN:
            r.append([dic_cmd[PENDOWN]])
        elif current == FORWARD:
            
            # slice on the argument of the command
            sub = s[i+1:]


            
            if sub[0] == " ":
                print("[FATAL] Bad instruction")
                exit(-1)

            arg, n = r_arg(dic_cmd, sub)

            i += n

            r.append([dic_cmd[FORWARD], arg])
            continue

        elif current == BACKWARD:
            sub = s[i+1:]


            if sub[0] == " ":
                print("[FATAL] Bad instruction")
                exit(-1)

            arg, n = r_arg(dic_cmd, sub)

            i += n

            r.append([dic_cmd[BACKWARD], arg])
            continue

        elif current == LEFT:
            sub = s[i+1:]

            if sub[0] == " ":
                print("[FATAL] Bad instruction")
                exit(-1)

            arg, n = r_arg(dic_cmd, sub)

            i += n

            r.append([dic_cmd[LEFT], arg])
            continue

        elif current == RIGHT:
            sub = s[i+1:]

            if sub[0] == " ":
                print("[FATAL] Bad instruction")
                exit(-1)

            arg, n = r_arg(dic_cmd, sub)

            i += n

            r.append([dic_cmd[RIGHT], arg])
            continue

        elif current == HOME:
            r.append([dic_cmd[HOME]])

        i += 1

    return r

# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=
# Init

s = turtle.Screen()
t = turtle.Turtle()

si = 'b100 r90 f150 '

li = parse_str(si, t)

print(parse_str(si, t))

for l in li:
    if len(l) == 1:
        l[0]()
        continue
    l[0](l[1])


s.mainloop()

# 
# =-=-=-=-=-=-=-=-=-=-=-=-=-=-=