... at least at first. You can get so bogged down in editing as you go that you end up doing very little writing. I find that that has a negative effect on my mood. I prefer to have written a fair amount, rather than not very much.
In any case, it's not easy to write and edit at the same time and do both tasks well.
So, my advice, to myself as well as everyone else, is: write now, edit later.