On Sun, 15 Nov 2015 09:53 am, Random832 wrote: > Marko Rauhamaa <ma...@pacujo.net> writes: >> Actually, the real question is, is the unary - *really* so useful that >> it merits existence or is it just something that was mindlessly copied >> into programming languages from elementary school arithmetics? > > The alternative, if you want to be able to specify negative numbers at > all, is to put - in the literal syntax. So what's "x-1"? > > I suppose you could use some *different* symbol in the literal syntax > for negative numbers. I had a calculator once that used a different > symbol (looked like a small superscript minus sign) for it. But Python > is limited to ASCII for basic syntax elements for good reasons.
I have a textbook for Pascal programming which includes a project to write an "arithmetic evaluator". It uses ~ for unary minus and - for binary subtraction, and doesn't include unary plus. The reason was to simplify the parser, so that every symbol had exactly one meaning. So in an alternate universe where Guido was less influenced by C, or where he wasn't as good as writing parsers as the real GvR is, we may have ended up with ~ for unary minus and no unary plus. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
