 How to reduce sloppy mistakes?
pg: Making fewer mistakes isn't the only solution.  You can also make them cost less.For example, I make a lot more typing mistakes typing into text editors than I used to do when typing on a typewriter.  But I type net faster, by a lot, because fixing mistakes is so easy.There are several ways to make mistakes cost less in programs: writing functional code; using a very abstract language; writing programs in layers; testing every change as you make it, in a repl.You can switch modes, too.  I sometimes start by writing something rapidly and comparatively carelessly, and then later when I reach a natural stopping point, I'll reread it carefully.