import base::*; import syntax::ast; import std::io::writer_util; fn expand_syntax_ext(cx: ext_ctxt, sp: codemap::span, arg: ast::mac_arg, _body: ast::mac_body) -> @ast::expr { let arg = get_mac_arg(cx,sp,arg); cx.print_backtrace(); std::io::stdout().write_line(print::pprust::expr_to_str(arg)); //trivial expression ret @{id: cx.next_id(), node: ast::expr_rec([], option::none), span: sp}; }