@Ichoran My suggestion is in practice, your codestyle is going to be "No trailing comma", so for your codebase, all of the code is going to be written as such.
Even when it comes to libraries, I would say most of the time, single line uses will not have a trailing comma, only when multiline is the trailing comma going to see large amounts of use.
Just because it compiles, doesn't mean it will become the "norm" , and your going to have to read
List(atan2(why, eks), 4, false, ) everyday
TBH I'm not fussed either way (I guess it would make my diffs cleaner)
f(x,y,z)has nothing to do with IDEs, either extant or idealized. In the SIP meeting, Adriaan took the stance that it's an editor issue. I would say that comment folding is an editor issue; or #ifdef as an editor action to pull source from two git branches is an editor issue. Here, the equivalence of two syntactic forms has nothing to do with tooling; all syntax is trivially just some tooling paraphernalia. Unless the trailing comma form is demonstrably ambiguous in a way that harms error reporting, then it's no different from the presence or absence of semicolons.