//! 停止指令 —— 对应 Java `freemarker.core.StopInstruction`
//! (accept :43-49:抛 StopException;消息经 evalAndCoerceToPlainText)
use crate::core::exec::{eval_to_string, ExecOutcome};
use crate::core::Expr;
use crate::error::Result;
/// `<#stop>` / `<#stop "msg">` 指令(对应 StopInstruction.java)
pub struct StopInstruction {
pub msg: Option<Expr>,
}
impl StopInstruction {
/// 构造(Java 构造器;Rust 侧由解析器产生)
pub fn new(msg: Option<Expr>) -> Self {
StopInstruction { msg }
}
/// 执行(Java accept → StopException)
pub(crate) fn exec(&self, env: &mut crate::core::Environment) -> Result<ExecOutcome> {
let message = match &self.msg {
Some(e) => Some(eval_to_string(env, e)?),
None => None,
};
Ok(ExecOutcome::Stop(message))
}
}