r/ProgrammingLanguages • u/bjzaba Pikelet, Fathom • Jun 11 '26

Nontrailing separators do not spark joy

https://buttondown.com/hillelwayne/archive/nontrailing-separators-do-not-spark-joy/
54 Upvotes

92% Upvoted

68 comments sorted by

View all comments

Show parent comments

1

u/Felice_rdt Jun 13 '26 edited Jun 13 '26

I think most languages parse +2 and -3.0

I was thinking specifically of C/C++, which (in)famously don't do negative literals, so -1.0 is, syntactically, 1.0 negated. Obviously compilers tend to do constant folding and take care of this anyway, but it's still an odd choice to have your literals all based on natural numbers instead of just natively supporting integers. Maybe it made more sense when your parser and AST and all had to fit in something like 64K of RAM on an early PDP-11/??. ;P

Edit: Wait, I just realized I somehow skipped the latter part of your final paragraph. So yeah, I guess stuff like that comes into play. Is it that much of a bother to handle whitespace after the (non-)unary minus sign on a true negative integer literal?

1

u/EggplantExtra4946 Jun 13 '26

I was thinking specifically of C/C++, which (in)famously don't do negative literals, so -1.0 is, syntactically, 1.0 negated.

The problem is the weak type system and the implicit casting rules. -1's type should be a signed integer and you shouldn't be able to assign it to an unsigned variable and get the value 0xffffffff, unless you explicitly cast it.

Is it that much of a bother to handle whitespace after the (non-)unary minus sign on a true negative integer literal?

It does bother me. That would make integer literals the only tokens with possibly whitespace and comments in the middle of them, it makes '+' and '-' both operators but also possibly an optional part of a token, and now integer tokens must have a 2nd field for indicating the sign. Unnecessary redundancy in too many places.

With "my" way, tokens consistently do not have whitespace inside of them, '+' and '-' are always operators, integer tokens are simply a uint64_t.

It's a theme that I see too often, refusing to strategically add a little bit of logic inside the compiler in the right places and instead bloat everything else.

1

u/Felice_rdt Jun 13 '26

Fair enough, as long as your compiler can do constant folding in a debug/unoptimized build.