Some(expr_tt({expander: exp, span: exp_sp})) => {
let expanded = match exp(cx, mac.span, tts) {
mr_expr(e) => e,
+ mr_expr_or_item(expr_maker,_) => expr_maker(),
_ => cx.span_fatal(
pth.span, fmt!("non-expr macro in expr pos: %s",
*extname))
mr_expr(_) => cx.span_fatal(pth.span,
~"expr macro in item position: " +
*extname),
+ mr_expr_or_item(_, item_maker) =>
+ option::chain(item_maker(), |i| {fld.fold_item(i)}),
mr_def(mdef) => {
exts.insert(mdef.name, mdef.ext);
None
-use base::{ext_ctxt, mac_result, mr_expr, mr_def, expr_tt};
+use base::{ext_ctxt, mac_result, mr_expr_or_item, mr_def, expr_tt};
use codemap::span;
use ast::{ident, matcher_, matcher, match_tok,
match_nonterminal, match_seq, tt_delim};
// rhs has holes ( `$id` and `$(...)` that need filled)
let trncbr = new_tt_reader(s_d, itr, Some(named_matches),
~[rhs]);
- let p = Parser(cx.parse_sess(), cx.cfg(),
- trncbr as reader);
- let e = p.parse_expr();
- return mr_expr(e);
+ let p = @Parser(cx.parse_sess(), cx.cfg(),
+ trncbr as reader);
+
+ // Let the context choose how to interpret the result.
+ // Weird, but useful for X-macros.
+ return mr_expr_or_item(|| p.parse_expr(),
+ || p.parse_item(~[/* no attrs*/]));
}
failure(sp, msg) => if sp.lo >= best_fail_spot.lo {
best_fail_spot = sp;