🚀 go-pugleaf

In article <480eio$2uf@news0.rain.rg.net> Paul Long <plong@perf.com> writes:
>Lawrence Kirby <fred@genesis.demon.co.uk> wrote:
>[snip]
>>Writing it as:
>>
>>do outer
>>{
>>} while ()
>>
>>seems to be most consistent with the other constructs.
>
>It's hard to parse. As an experiment, awhile back I added Andrew's
>label to a YACC grammar for Standard C. YACC reported an ambiguity
>with a label after the "do." I believe it had something to do with
>YACC not having enough lookahead. For example, the grammar could
>probably be expressed with an LALR(2) YACC.

Whoops, I remembered wrong! It's not simply that there is a conflict
(specifically, a shift/reduce conflict), the problem is that, as
Charles Fu indicated in another article, the grammar is ambiguous
and no amount of lookahead will help. Expanding on what Charles
wrote, this looks like a labeled do with an empty statement, right?

    do outer
        ;
    while (0);

Okay, but in the following form, it also looks like an unlabeled do
with a statement that contains a single identifier.

    do
        outer;
    while (0);

If I can't figure out what it is, neither can the compiler. Let's
try something else, or better yet, let's give up. :-)

Paul Long         plong@perf.com       http://www.teleport.com/~pciwww/
  "A perfect method should not only be an efficient one, as respects
  the accomplishment of the objects for which it is designed, but
  should in all its parts and processes manifest a certain unity and
  harmony." - George Boole, _An Investigation of the Laws of Thought_