from core.environment import IGNORE, MEANINGFUL
import re

def processString(source: str) -> str:
    """Remove blank characters and comments from source code.

    Args:
        source: The source code string.

    Returns:
        The cleaned source code.
    """
    source = source.lstrip(IGNORE)

    while source and source[0] == ";":
        line_end: int = source.find("\n")

        if line_end < 0:
            return ""

        source = source[line_end:].lstrip(IGNORE)

    return source


def findPrefix(source: str, separators: str = IGNORE + MEANINGFUL) -> str:
    """Find a meaningful prefix (token) in the source string.

    Args:
        source: The source code string.
        separators: Characters that mark token boundaries.

    Returns:
        The prefix token found, or empty string if none.
    """
    pattern: str = rf"^[^{separators}]*"
    match = re.match(pattern, source)
    return match.group(0) if match else ""