convertor.py

import math

defaultbits = 8

def char_to_int(s):
    return int(s, 36)

def int_to_char(i):
    if 0 <= i <= 9:
        return str(i)
    elif 10 <= i <= 36:
        return chr(ord('a') + i - 10)
    else:
        print("error trying to convert", i, "to a character.")
        return " <x> "

def invert_bitstring(s):
    inverted = ""
    for char in s:
        if char == "0": inverted += "1"
        else: inverted += "0" # interpreting every character but "0" as a "1"
    return inverted

def Radix(base):
    class Number:
        def base(self):
            return base
        
        def __init__(self, value):
            self.val = 0
            if type(value) == str:
                self.from_string(value)
            elif type(value) == int:
                self.val = value
            else:
                self.val = value.val
        
        def from_string(self, s):
            self.val = int(s, base)
        
        def to_string(self, minlength = 0):
            s = ""
            sign = ""
            value = self.val
            if self < 0:
                sign = "-"
                value = abs(self.val)
            
            remainders = []
            while value != 0:
                remainders.append(int_to_char(value % base))
                value = value // base
            # inverting the remainders
            s += "".join(remainders[::-1])
            
            return sign + "0"*max(minlength-len(s), 0) + s
            
        def __lt__(self, other):
            if int(self) < int(other):
                return True
            return False
        
        def __le__(self, other):
            if int(self) <= int(other):
                return True
            return False
        
        def __eq__(self, other):
            if int(self) == int(other):
                return True
            return False
        
        def __int__(self):
            return self.val
        
        def __str__(self):
            return self.to_string()
        
        def __repr__(self):
            return self.to_string()
    
    return Number


Bin = Radix(2)
Oct = Radix(8)
Hex = Radix(16)


class TwoCom(Bin):
    def __init__(self, value, length = defaultbits):
            self.val = 0
            if type(value) == str:
                self.from_string(value)
                self.length = len(value)
            elif type(value) == int:
                self.val = value
                self.length = length
            else:
                self.val = value.val
                self.length = length
        
    def from_string(self, s):
        if s[0] == "1":
            self.val = -(int(Bin(invert_bitstring(s)))+1)
        else:
            self.val = Bin(s).val
        
    def to_string(self):
        # length is the fixed this time!
        
        if not -(2**self.length-1) <= self.val <= (2**self.length-1)-1:
            print("Not enough bits. A better choice would be",math.ceil(math.log(abs(self.val), 2)),"instead of",self.length)
            return "----"
        s = ""
        if self.val < 0:
            s = "1" + invert_bitstring(Bin(abs(self.val)-1).to_string(self.length-1))
        else:
            s = "0" + Bin(self.val).to_string(self.length-1)
        
        return s