On Fri, Dec 14, 2012 at 04:08:09PM +0100, Paulo Pinto wrote: > On Friday, 14 December 2012 at 08:40:59 UTC, Walter Bright wrote: > >On 12/13/2012 11:34 PM, Jacob Carlborg wrote: > >>On 2012-12-13 22:26, Walter Bright wrote: > >> > >>>CTFE would catch it. > >> > >>Didn't you just say that flow analysis is needed for that? > >> > > > >CTFE executes at compile time, no flow analysis is needed for > >that. DFA is something very different - it "executes" all paths > >simultaneously. > > What is the issue with flow analysis and D? > > Even on the toy compiler I had to create back in the university we > implemented flow analysis for a few use cases. > > So the question is if toy university compilers have flow analysis > why not having it in D? [...]
Yeah I'm curious about this too. I also have implemented basic flow analysis in a compiler project in university. For the simple cases, it doesn't complicate the compiler that much at all. For a sophisticated compiler such as DMD, basic flow analysis would almost seem trivial. (But then again, it may add performance bottlenecks that I'm unaware of -- this was before I learnt the hard way that hotspots often aren't actually where you think they are.) T -- Acid falls with the rain; with love comes the pain.
