Communicate on GitHub PRs using only emoji

thumbs.py

#!/bin/env python3
from typing import Callable, TypeVar, TextIO, Iterable
T = TypeVar("T")
chars = ["👍", "👎", "😄", "🎉", "😕", "🧡", "🚀", "👀"]

def chunk(size: int, xs: list[T]) -> Iterable[list[T]]:
    for ix in range(0, len(xs), size):
        yield xs[ix : ix+size]

def thumbs(s: str) -> str:
    def bits(b: bytes) -> list[bool]:
        return [bool(byte & (1 << bit)) for byte in b for bit in range(8)]

    def digit(bits: list[bool]) -> int:
        return sum([1 << ix if bit else 0 for (bit, ix) in zip(bits, range(3))])

    def digits(s: str) -> list[int]:
        b = bytes(s, "utf-8")
        return list(map(digit, chunk(3, bits(b))))

    def char(digit: int) -> str:
        return chars[digit]

    return ''.join(map(char, digits(s)))

def unthumbs(s: str) -> str:
    def digits(s: str) -> list[int]:
        return [chars.index(c) for c in s]

    def bits(digit: int) -> list[bool]:
        return [bool(digit & (1 << bit)) for bit in range(3)]

    def byte(bits: list[bool]) -> int:
        return sum([1 << ix if bit else 0 for (bit, ix) in zip(bits, range(8))])

    allBits = [bit for digit in digits(s.strip()) for bit in bits(digit)]
    allBytes = [byte(b) for b in chunk(8, allBits)]
    return ''.join([chr(byte) for byte in allBytes])

def translate(tr: Callable[[str], str], stdin: TextIO) -> None:
    for line in stdin:
        print(tr(line))

if __name__ == "__main__":
    from sys import argv, stdin
    tr = unthumbs if len(argv) > 1 and argv[1] == "-r" else thumbs
    translate(tr, stdin)