Function compose 

pub fn compose(
    approach: &Approach,
    constraints: &[Item],
    questions: &[Item],
    session: &str,
    hash: impl Fn(&[u8]) -> String,
) -> Result<Brief, String>

The brief the person’s choice makes, deterministically: the approach verbatim, then the kept constraints and open questions. hash is the hex SHA-256 the runtime supplies; the digest covers the body only, so the header can name it.

Errors

The brief is larger than BRIEF_MAX.