svoid tok_swappableFunctions(LS tok) {

  jreplace(tok, "swappable static", "static swappable");

  jreplace(tok, "pswappable <id>", "persistently swappable $2");

  int i;

  while ((i = jfind(tok, "swappable <id> <id>(")) >= 0) {

    int iModEnd = i;

    bool persistently = eqGet(tok, i-2, "persistently");

    if (persistently) iModEnd -= 2;

    int iMod = leftScanModifiers(tok, iModEnd);

    S modifiers = joinSubList(tok, iMod, iModEnd);

    S returnType = tok.get(i+2), name = tok.get(i+4);

    int iCurly = indexOf(tok, i, "{");

    LS tokArgs = subList(tok, i+7, iCurly-2);

    LPairS args = tok_typesAndNamesOfParams(tokArgs);

    S args1 = join(tokArgs);

    S args2 = joinWithComma(pairsB(args));

    bool isVoidMethod = eq(returnType, "void");

    LS types = pairsA(args);

    if (!isVoidMethod) types.add(returnType);

    S typeParams = joinWithComma(map tok_toNonPrimitiveTypes(types)); // TODO: modifiers

    S base = name + "_base";

    S mods = modifiers + (persistently || containsJavaToken(modifiers, "static") ? "" : "transient ");

    S src;

    if (isVoidMethod)

      if (empty(args))

        src = mods + "Runnable \*name*/;\n" + 

          "\*modifiers*/\*returnType*/ \*name*/(\*args1*/) { if (\*name*/ != null) \*name*/.run(\*args2*/); else \*base*/(\*args2*/); }\n" +

          "\*modifiers*/\*returnType*/ \*base*/(\*args1*/) {";

      else

        src = mods + "IVF\*l(args)*/<\*typeParams*/> \*name*/;\n" + 

          "\*modifiers*/\*returnType*/ \*name*/(\*args1*/) { if (\*name*/ != null) \*name*/.get(\*args2*/); else \*base*/(\*args2*/); }\n" +

          "\*modifiers*/\*returnType*/ \*base*/(\*args1*/) {";

    else

      src = mods + "IF\*l(args)*/<\*typeParams*/> \*name*/;\n" + 

        "\*modifiers*/\*returnType*/ \*name*/(\*args1*/) { ret \*name*/ != null ? \*name*/.get(\*args2*/) : \*base*/(\*args2*/); }\n" +

        "\*modifiers*/\*returnType*/ \*base*/(\*args1*/) {";

    replaceTokens_reTok(tok, iMod, iCurly+1, src);

  }

}