brainfuck_generator.py

import argparse

# Clears the current and the next cell.
# Uses current cell as a counter for a loop that increments the next cell 10 times. Loop runs for the number given by
# the integer division of the ASCII code by 10.
# The final ASCII code is obtained by further incrementing the cell based on the remainder of the division by 10.


def char_to_bf(char):
    buffer = "[-]>[-]<"
    for i in range(ord(char)//10):
        buffer = buffer + "+"
    buffer = buffer + "[>++++++++++<-]>"
    for i in range(ord(char) % 10):
        buffer = buffer + "+"
    buffer = buffer + ".<"
    return buffer


# Uses a similar algorithm to char_to_bf(), but can also decrement, based on the sign of the given argument.
# Optimizes the final Brainfuck source code by altering the current value in the cell, instead of clearing and
# starting from 0.


def delta_to_bf(delta):
    buffer = ""
    for i in range(abs(delta) // 10):
        buffer = buffer + "+"

    if delta > 0:
        buffer = buffer + "[>++++++++++<-]>"
    else:
        buffer = buffer + "[>----------<-]>"

    for i in range(abs(delta) % 10):
        if delta > 0:
            buffer = buffer + "+"
        else:
            buffer = buffer + "-"
    buffer = buffer + ".<"
    return buffer


# Uses the previous helper functions to generate Brainfuck source that prints the string argument of this function.
# The commented argument puts code that generates one character on a new line and appends the printed character, which
# is considered a comment in Brainfuck. Valid Brainfuck source characters are stripped.


def string_to_bf(string, commented):
    buffer = ""
    if string is None:
        return buffer
    for i, char in enumerate(string):
        if i == 0:
            buffer = buffer + char_to_bf(char)
        else:
            delta = ord(string[i]) - ord(string[i - 1])
            buffer = buffer + delta_to_bf(delta)
        if commented:
            buffer = buffer + ' ' + string[i].strip('+-<>[],.') + '\n'
    return buffer


def main():
    parser = argparse.ArgumentParser(description='Text to Brainfuck generator. (C) Stelian Saracut 2018.')
    parser.add_argument('--string', metavar='S', help='String to be printed by Brainfuck source code.')
    parser.add_argument('--file', metavar='O', help='Brainfuck output file. Leave blank to output to console.')

    args = parser.parse_args()

    source_code = string_to_bf(args.string, True)

    if args.file is None:
        print(source_code)
    else:
        file = open(args.file, 'w')
        file.write(source_code)
        file.close()


if __name__ == '__main__':
    main()