Method depth

crates/kernel/src/tc.rs:334–336

Current logical binding depth. During the FVar transition, some code pushes legacy de-Bruijn locals into `ctx` while newer code opens binders into `lctx`. Most paths use one or the other, but mixed validation code can observe both; the logical depth is the sum of the two stacks.

(&self)

  /// the other, but mixed validation code can observe both; the logical depth
  /// is the sum of the two stacks.
  pub fn depth(&self) -> u64 {
    (self.ctx.len() + self.lctx.len()) as u64
  }

  /// WHNF cache key: (expr_hash, ctx_hash).
  ///