message: Rename _ctx to eval when it refers to an evaluator
  Summary: Consitency
diff: @@ -47,7 +47,7 @@ enum Next {
  Fail, // Stop running
  }
  -fn cmd_help(_ctx: &mut Evaluator) -> anyhow::Result<Next> {
  +fn cmd_help(_eval: &mut Evaluator) -> anyhow::Result<Next> {
  for (name, msg, _) in COMMANDS {
  eprintln!("* :{}, {}", name[0], msg)
  }
  @@ -76,11 +76,11 @@ fn cmd_stack(eval: &mut Evaluator) -> anyhow::Result<Next> {
  Ok(Next::Again)
  }
  -fn cmd_resume(_ctx: &mut Evaluator) -> anyhow::Result<Next> {
  +fn cmd_resume(_eval: &mut Evaluator) -> anyhow::Result<Next> {
  Ok(Next::Resume)
  }
  -fn cmd_fail(_ctx: &mut Evaluator) -> anyhow::Result<Next> {
  +fn cmd_fail(_eval: &mut Evaluator) -> anyhow::Result<Next> {
  Ok(Next::Fail)
  }
  