Replaces all instances of try! in a rust codebase with the ? operator. I used this because I can't use rustfmt.

rust_try_replacer.py

import os
import re
import sys

TRY_PATTERN = re.compile(r"try!\(")

def replace_try(contents):
    match = TRY_PATTERN.search(contents)

    if match:
        span = match.span(0)
        before = contents[:span[0]]
        after = contents[span[1]:]
        paren_count = 0

        for i, c in enumerate(after):
            if c == "(":
                paren_count += 1
            elif c == ")":
                if paren_count == 0:
                    after = after[:i] + "?" + after[i+1:]
                    break
                elif paren_count < 0:
                    raise Exception()
                else:
                    paren_count -= 1

        return replace_try(before + after)
    else:
        return contents

def main(dir):
    for root, _, files in os.walk(dir):
        for filename in files:
            if filename.endswith(".rs"):
                with open(os.path.join(root, filename), "r") as f:
                    contents = f.read()

                contents = replace_try(contents)

                with open(os.path.join(root, filename), "w") as f:
                    f.write(contents)

if __name__ == "__main__":
    # To run: python3 rust_try_replacer.py <root dir of rust codebase>
    main(sys.argv[1])