sS gazelle_deepReplaceVars(SS map, S s, O... _) {
  SS map2 = mapValues roundIfMultipleTokensUnlessCurlyBracketed(map);
  ret gazelle_deepReplaceVars_impl(map2, s, _);
}

sS gazelle_deepReplaceVars_impl(SS map, S s, O... _) {
  LS tok = javaTokWithBrackets(s);
  ret join(mapCodeTokens(tok, t -> {
    //bool round = tok_isRoundBracketed(t);
    //bool curly = tok_isCurlyBracketed(t);
    S t2 = tok_deRoundOrCurlyBracket(t);
    S t3 = map.get(t2);
    ifdef gazelle_deepReplaceVars_debug
    print("sub lookup: " + quote(t2) + " => " + quote(t3));
    endifdef
    if (t3 != null) ret t3;
    if (l(tok) == 3) ret t;
    S t4 = gazelle_deepReplaceVars_impl(map, t2, _);
    if (eq(t4, t2)) ret t;
    //ret round ? roundBracket(t4) : curlyBracket(t4);
    ret roundBracketOptIfMoreThanOneToken(t4);
  }));
}

Began life as a copy of #1025738