grass/src/builtin/meta.rs

use std::collections::BTreeMap;

use super::Builtin;
use crate::value::Value;

pub(crate) fn register(f: &mut BTreeMap<String, Builtin>) {
    f.insert(
        "if".to_owned(),
        Box::new(|args| {
            let cond: &Value = arg!(args, 0, "condition");
            let if_true = arg!(args, 1, "if-true").clone();
            let if_false = arg!(args, 2, "if-false").clone();
            if cond.is_true() {
                Some(if_true)
            } else {
                Some(if_false)
            }
        }),
    );
}