//! What the rigs need and none of them should spell its own way. Every
//! fuzzer and measurement here is run by hand with its parameters in the
//! environment, so one reader is shared rather than copied into each target.

/// A rig's parameter from the environment, or its default. A switch is
/// `env("NAME", 0_u8) != 0`, so `NAME=1` turns it on.
pub fn env<T: std::str::FromStr>(name: &str, fallback: T) -> T {
    std::env::var(name)
        .ok()
        .and_then(|value| value.parse().ok())
        .unwrap_or(fallback)
}

/// The seeds a scan runs: the one `one` names on its own, or `1..=` the
/// count `many` gives. One seed replaces the range rather than narrowing
/// it, which is how a tree a scan failed on is run again by itself.
// This module is compiled into each rig target separately, so a helper the
// measurement rigs have no seeds to choose is dead code in those builds.
#[allow(dead_code)]
pub fn seeds(one: &str, many: &str, count: u64) -> Vec<u64> {
    match std::env::var(one).ok().and_then(|seed| seed.parse().ok()) {
        Some(seed) => vec![seed],
        None => (1..=env(many, count)).collect(),
    }
}