Method try_generate_name

src/sql-parser/src/ast/defs/name.rs:163–198

Generate a valid [`Ident`] with the provided `prefix` and `suffix`. # Examples ``` use mz_sql_parser::ast::{Ident, IdentError}; let good_id = Ident::try_generate_name("hello", "_world", |_| Ok::<_, IdentError>(true)).unwrap(); assert_eq!(good_id.as_str(), "hello_world"); // Return invalid once. let mut attempts = 0; let one_failure = Ident::try_generate_name("hello", "_world", |_candidate| { i

(prefix: P, suffix: S, mut is_valid: F)

    /// assert_eq!(one_failure.as_str(), "hello_world_1");
    /// ```
    pub fn try_generate_name<P, S, F, E>(prefix: P, suffix: S, mut is_valid: F) -> Result<Self, E>
    where
        P: Into<String>,
        S: Into<String>,
        E: From<IdentError>,
        F: FnMut(&Ident) -> Result<bool, E>,
    {
        const MAX_ATTEMPTS: usize = 1000;

        let prefix: String = prefix.into();
        let suffix: String = suffix.into();

        // First just append the prefix and suffix.
        let mut candidate = Ident(prefix.clone());
        candidate.append_lossy(suffix.clone());
        if is_valid(&candidate)? {
            return Ok(candidate);
        }

        // Otherwise, append a number to the back.
        for i in 1..MAX_ATTEMPTS {
            let mut candidate = Ident(prefix.clone());
            candidate.append_lossy(format!("{suffix}_{i}"));

            if is_valid(&candidate)? {
                return Ok(candidate);
            }
        }

        // Couldn't find any valid name!
        Err(E::from(IdentError::FailedToGenerate {
            prefix,
            suffix,
            attempts: MAX_ATTEMPTS,
        }))
    }

    /// Append the provided `suffix`, truncating `self` as necessary to satisfy our invariants.
    ///