hakorune/src/parser/sugar_gate.rs

use std::cell::Cell;

thread_local! {
    static SUGAR_ON: Cell<bool> = Cell::new(false);
}

pub fn is_enabled_env() -> bool {
    if std::env::var("NYASH_FORCE_SUGAR").ok().as_deref() == Some("1") { return true; }
    matches!(std::env::var("NYASH_SYNTAX_SUGAR_LEVEL").ok().as_deref(), Some("basic") | Some("full"))
}

pub fn is_enabled() -> bool {
    SUGAR_ON.with(|c| c.get()) || is_enabled_env()
}

pub fn with_enabled<T>(f: impl FnOnce() -> T) -> T {
    SUGAR_ON.with(|c| {
        let prev = c.get();
        c.set(true);
        let r = f();
        c.set(prev);
        r
    })
}