Function decode_line 

pub fn decode_line(line: &str, line_number: u64) -> Result<Message, Error>

Parse one stream-json line into a Message.

line must not include a trailing newline. line_number is used only for error reporting and should be 1-based.

Errors

• Error::JsonDecode when the line is not valid JSON.
• Error::MessageParse when the JSON parses but doesn’t match any known message shape.