🚀 go-pugleaf

Fredrik Bredberg (konfrbr@euax7i3c01.eua.ericsson.se) wrote:
: Andrew Dunbar (andrewd@agnus.livewire.com.au) wrote:
: :
: : Has anyone thought of the possibility of 'named' loops?
: :
: : for outer (x = 0; x < MAXX; x++)
: : {
: :    for inner (y = 0; y < MAXY; y++)
: :    {
: :       if (map[y][x] == '*')
: :          break (outer);
: :    }
: : }

: I think that Andrew's `named' loops is the best alternative to this
: problem that I'v seen so far! The main reason for this is that the
: `label' is so closely coupled to the loop constructor.

What I think is wrong with 'named loops':

1) It's a completely new syntax for C. This makes learning it difficult.
2) It's a completely new syntax for C. This makes parsing it difficult.
   Specifically it looks like a function call inner() yet it is actually
   a label. Major grief for the lexer/parser interface. So at a minmum
   there should be a ':' after the label to help the lexer. If you
   do that why not swap the order of the label and the for/while token
   and do it like Java!
3) It gains us virtually nothing. Remember we can't get rid of goto!
   So we are introducing a new construct that duplicates things that
   can be done with goto.

The only benefit would be better error checking, because 'break <label>'
can be used in fewer situations than 'goto <label>'. But what sort of
errors can we catch with this construct?

1) Do it like Java.
2) Leave it as it is.

--
Erik Corry ehcorry@inet.uni-c.dk