code.py

"""
This module contains 3 functions that do the actual conversion of
mnemonics to binary code
"""


def computation(cmp):
    """
    This function computes the computation mnemonic
    :param cmp: assembly code of the computation mnemonic
    :return:  binary equivalent of the mnemonic
    """
    mnem = {
        # a == 0
        "0":    "0101010",
        "1":    "0111111",
        "-1":   "0111010",
        "D":    "0001100",
        "A":    "0110000",
        "!D":   "0001101",
        "!A":   "0110001",
        "-D":   "0001111",
        "-A":   "0110011",
        "D+1":  "0011111",
        "A+1":  "0110111",
        "D-1":  "0001110",
        "A-1":  "0110010",
        "D+A":  "0000010",
        "D-A":  "0010011",
        "A-D":  "0000111",
        "D&A":  "0000000",
        "D|A":  "0010101",
        # a == 1
        "M":    "1110000",
        "!M":   "1110001",
        "-M":   "1110011",
        "M+1":  "1110111",
        "M-1":  "1110010",
        "D+M":  "1000010",
        "D-M":  "1010011",
        "M-D":  "1000111",
        "D&M":  "1000000",
        "D|M":  "1010101"
    }
    return mnem.get(cmp)


def destination(dest):
    """
    This function computes the destination mnemonic
    :param dest: assembly code of destination
    :return: binary code of mnemonic
    """
    mnem = {
        "M":    "001",
        "D":    "010",
        "MD":   "011",
        "A":    "100",
        "AM":   "101",
        "AD":   "110",
        "AMD":  "111"
    }
    return mnem.get(dest, "000")


def jump(jmp):
    """
    This function computes the machine code equivalent jump mnemonic
    :param jmp: the jump assembly mnemonic
    :return: the binary code equivalent, if @jmp is null return 000
    """
    mnem = {
        "JGT":  "001",
        "JEQ":  "010",
        "JGE":  "011",
        "JLT":  "100",
        "JNE":  "101",
        "JLE":  "110",
        "JMP":  "111",
    }
    return mnem.get(jmp, "000")