from typing import Iterator
import xml.etree.ElementTree as ET

def stop_before_value(iterator: Iterator[str], stop_value: str) -> Iterator[str]:
    """
    Creates an iterator that yields values from the input iterator
    until it encounters the stop_value (exclusive).
    
    Args:
        iterator: The source iterator
        stop_value: The value to stop before
        
    Yields:
        Values from the iterator until stop_value is encountered
        If stop_value is part of an item, yields the part before stop_value
    """
    for item in iterator:
        if stop_value in item:
            split_point = item.index(stop_value)
            if split_point > 0:
                yield item[:split_point]
            break
        yield item

def escape_text_for_xml(text: str) -> str:
    """
    Convert any text value to a properly escaped XML string.
    
    Args:
        text: Text to escape, can be string, number, or None
        
    Returns:
        str: XML-escaped string representation
    """
    if text is None:
        return ''
    
    # Convert numbers to strings
    text_str = str(text)
    
    # Standard XML escaping if string contains CDATA end sequence
    if ']]>' in text_str:
        return text_str.replace('&', '&') \
                      .replace('<', '&lt;') \
                      .replace('>', '&gt;') \
                      .replace('"', '&quot;') \
                      .replace("'", '&apos;')
    
    # Otherwise wrap in CDATA
    return f'<![CDATA[{text_str}]]>'