(syn \\ (s base share)
  (list (pcase (peek s)
          no     (err 'escape-without-char)
          breakc (rdc s)
                 (let cs (charstil s breakc)
                   (if (cdr cs)
                       (aif (get (sym cs) namecs)
                            (cdr it)
                            (err 'unknown-named-char))
                       (car cs))))
        share))

(syn \' (s base share)
  (rdwrap s 'quote base share))

(syn \` (s base share)
  (rdwrap s 'bquote base share))

(syn \, (s base share)
  (case (peek s)
    \@ (do (rdc s)
           (rdwrap s 'comma-at base share))
       (rdwrap s 'comma base share)))

(def rdwrap (s token base share)
  (let (e newshare) (hard-rdex s base share 'missing-expression)
    (list (list token e) newshare)))

(syn \" (s base share)
  (list (rddelim s \") share))

(syn \¦ (s base share)
  (list (sym (rddelim s \¦)) share))

(def rddelim (s d (o esc))
  (let c (rdc s)
    (if (no c)   (err 'missing-delimiter)
        esc      (cons c (rddelim s d))
        (= c \\) (rddelim s d t)
        (= c d)  nil
                 (cons c (rddelim s d)))))

(syn \# (s base share)
  (let name (charstil s ~digit)
    (if (= (peek s) \=)
        (do (rdc s)
            (rdtarget s base name (join) share))
        (aif (get name share)
             (list (cdr it) share)
             (err 'unknown-label)))))

(def rdtarget (s base name cell oldshare)
  (withs (share        (cons (cons name cell) oldshare)
          (e newshare) (hard-rdex s base share 'missing-target))
    (if (simple e)
        (err 'bad-target)
        (do (xar cell (car e))
            (xdr cell (cdr e))
            (list cell newshare)))))

(def rdword (s c base)
  (parseword (cons c (charstil s breakc)) base))