dotfiles/bin/bitwisefun

#!/usr/bin/env python2

from __future__ import print_function

import sys

SYMBOLS = {
    '>>': 'bin_shift_right',
    '<<': 'bin_shift_left',
    '&': 'bin_and',
    '|': 'bin_or',
    '^': 'bin_xor',
    '~': 'bin_not',
}

def format_binary(num):
    """Shows instructive binary format, e.g. 1 byte."""
    return '{:08b}'.format(num)


def bin_not(num):
    """Bitwise OR."""
    return ~num1


def bin_and(num1, num2):
    """Bitwise AND."""
    return num1 & num2


def bin_or(num1, num2):
    """Bitwise OR."""
    return num1 | num2


def bin_xor(num1, num2):
    """Bitwise XOR."""
    return num1 ^ num2


def bin_shift_left(num1, num2):
    """Bitwise left shift."""
    return num1 << num2


def bin_shift_right(num1, num2):
    """Bitwise right shift."""
    return num1 >> num2

if __name__ == '__main__':
    try:
        symbol, num1, num2 = sys.argv[1:]
        num1 = int(num1)
        num2 = int(num2)
        try:
            func = SYMBOLS[symbol.lower()]
            func = globals()[func]
        except KeyError:
            print('Invalid symbol: "{}"'.format(symbol))
            print('\nValid symbols are:')
            for sym in SYMBOLS.keys():
                print('\t' + sym.upper())
            sys.exit(1)

        raw_out = func(num1, num2)
    except ValueError:
        symbol, num1 = sys.argv[1:]
        num2 = None
        if symbol != '~':
            raise
        num1 = int(num1)
        raw_out = bin_not(num1)

    ret = '\t'
    ret += format_binary(num1)
    ret += ' (decimal {})'.format(num1)
    ret += '\n{}\t'.format(symbol.upper())
    if num2:
        ret += format_binary(num2)
        ret += ' (decimal {})'.format(num2)
    ret += '\n----------------\n\t'
    ret += format_binary(raw_out)
    ret += ' (decimal {})'.format(raw_out)
    print(ret)