On 09/12/2013 05:39 PM, Timon Gehr wrote:
Lookahead is realized as follows in the parser:
(assume 'code' is the circular buffer range.)
auto saveState(){muteerr++; return code.pushAnchor();} // saves the
state and mutes all error messages until the state is restored
void restoreState(Anchor state){ muteerr--; code.popAnchor(state); }
The 'Anchor' is a trivial wrapper around a size_t. The circular buffer
grows automatically to keep around tokens still reachable by an anchor.
(The range only needs small constant space besides the buffer to support
this functionality, though it is unable to detect usage errors.)
Do you think it's possible to use CircularBufferRange itself as anchor.
Then calling save() would return a CircularBufferRange and you canould
scratch the two functions above. I had some promising experiments in
that direction, but the implicit save on copy is annoying because you
end up with anchors from temporary copies.
