@Kha I implemented the optional `,` at structure instances.
You have suggested it a few weeks/months ago. F# also implements this
feature. I got back to it while write documentation for Lean.
It looks quite nice when we are packing many functions into a structure.
BTW, F# also has optional separators for list literals :)
This is a much simpler change for us since `[...]` is defined using
the `syntax/macro_rules` commands, but I didn't find optional ','
would very useful since our list literals are usually in a single
line.
c9cbe35916