Method whnf_core

crates/kernel/src/whnf.rs:352–357

Structural WHNF: beta, iota, zeta. NO delta. FULL flags. This is the standard structural normalizer used outside the def-eq lazy-delta path. With `WhnfFlags::FULL`, recursive sub-reductions and `try_iota` use full delta on majors and projected values, matching pre-`WhnfFlags` behavior of `whnf_core`.

(
    &mut self,
    e: &KExpr<M>,
  )

    let key = self.whnf_key(e);
    let use_cache = nat_succ_mode == NatSuccMode::Collapse;
    let transient_nat_work = self.is_transient_nat_literal_work(e)?;
    if use_cache && !transient_nat_work {
      if let Some(cached) = self.env.whnf_cache.get(&key) {
        self.env.perf.record_whnf_hit();
        return Ok(cached.clone());
      }
      // Both probes missed.
      self.env.perf.record_whnf_miss();
      self.record_hot_miss("whnf", e);