PROPOSAL: Underscores in numbers (original) (raw)

Daniel Cheng j16sdiz at gmail.com
Tue Mar 31 01:07:49 PDT 2009

On Tue, Mar 31, 2009 at 3:14 PM, Bruce Chapman <brucechapman at paradise.net.nz> wrote:

Derek, thanks for writing this up, it saved me doing it. (and it would complement my integer literal proposals nicely)

A couple of comments: 1. I don't really like most of your decimal examples because (apart from the money one) although we talk about these as numbers, they are not numbers really, just identifiers whose significant elements consist solely of digits. As an explanation, prepending 00 to the front of any of these would yield a different (or invalid) phone/credit card/SS number, whereas prepending 00 to a number does not (but not in java where it makes an octal or a compiler error :), similarly add two together or subtracting them makes no sense. Real countable number examples that could be useful are populations, national debt, Long.MAXVALUE etc, as well as the hex and binary examples you use later. I am not convinced of the utility of multiple consecutive underscore separators, and I think the example that uses that is confusing and asking for trouble.

I am in favour of consecutive underscore -- I can use them to align digits over lines and this make parsing a bit easier

IMHO it would add to the value if you removed that option, but you might have some good use case you are thinking about. Similarly for underscore at either end seems strange. It might take more effort to describe it such that these are illegal, but I don't think anyone would complain at the absence of that form.

Any reason why in the syntax you didn't just add underscore to the various XXXXDigits forms (and maybe change the name a little) rather than the more complex approach, then describe the erasure of the underscore in the description of each form? Bruce

More information about the coin-dev mailing list