static bool ctxProcessIf(L<S> tok) {

  int i;

  if ((i = jfind(tok, "if (")) == 1) {

    int iEnd = findEndOfBracketPart(tok, i+2)-1;

    S cond = join(subList(tok, i+4, iEnd-1));

    bool yes = ctxEvalCondition(cond);

    assertEquals("{", tok.get(iEnd+2));

    int iEndYes = findEndOfBlock(tok, iEnd+2)-1;

    S yesCode = join(subList(tok, iEnd+4, iEndYes-1));

    int j = iEndYes+2;

    S noCode = "";

    if (eqGet(tok, iEndYes+2, "else")) {

      int iNo = iEndYes+4;

      assertEquals("{", tok.get(iNo));

      int iEndNo = findEndOfBlock(tok, iNo)-1;

      j = iEndNo+2;

      noCode = join(subList(tok, iNo+2, iEndNo-1));

    }

    replaceTokens_reTok(tok, i, j, yes ? yesCode : noCode);

    true;

  }

  false;

}