; A compact semantic regression for the compiler facilities used by the emitter.
(def feature-probe (flag symbol)
  (if (id flag 'pair)
      (wasm-bootstrap-copy (wasm-bootstrap-next (wasm-list-name
        (feature-protected-parameter symbol symbol symbol symbol symbol symbol symbol symbol symbol symbol))))
      (if flag
      (join (nom symbol) (join (feature-literal) (feature-quoted)))
      (join (id (feature-literal) (feature-literal))
            (join (id "same" "same")
                  (join (id \a (car "a")) (id symbol (feature-symbol))))))))
(def feature-literal () "literal")
(def feature-quoted () '"quoted")
(def feature-symbol () 'unknown)
(def feature-protected-parameter (no list append cons reduce scope globe map hug letu) no)
; Compiler-private names are outside the published bootstrap snapshot.
(def wasm-list-name (x) x)
(def wasm-bootstrap-next (x) x)
(def wasm-bootstrap-copy (x) x)