I've used moonscript a lot, and don't particularly like the \ syntax. However, you get used to it quickly, and it stops seeming like such a big deal.
It would be hard to have both be '.', because of lua semantics: '.' means "get the property from the table", while ':' in lua and '\' in moonscript mean "get the function from this table, with the first parameter for that function bound to the table itself".
Javascript/Coffeescript can get away with both being '.' because of the horrible mess that is implicit 'this'. All functions have an implicit first parameter, that non-method functions usually ignore, and '.' in javascript does the equivalent of ':' and '\' in moonscript (for functions). I find the lua approach much simpler and cleaner, and think it is actually more approachable than the javascript way, because the difference between '.' and ':' or '\' is conceptually simpler than all the rules behind 'this' in javascript.
Programming in Lua explains ':' in http://www.lua.org/pil/16.html , and probably has a better explanation that I wrote :).
I learned them concurrently, translating lua in Programming in Lua into the equivalent moonscript. It's a pretty strait-forward translation and is definitely doable. I already had experience with a reasonable variety of languages before learning it though, and for people still getting into programming, I think Lua is a simpler and still awesome language.
I don't think it's possible to learn moonscript without learning lua concurrently, since lua makes up so much of the underlying semantics. So I think the choice is either (a) learn lua, or (b) learn lua and moonscript for some nice syntactic sugar.
It would be hard to have both be '.', because of lua semantics: '.' means "get the property from the table", while ':' in lua and '\' in moonscript mean "get the function from this table, with the first parameter for that function bound to the table itself".
Javascript/Coffeescript can get away with both being '.' because of the horrible mess that is implicit 'this'. All functions have an implicit first parameter, that non-method functions usually ignore, and '.' in javascript does the equivalent of ':' and '\' in moonscript (for functions). I find the lua approach much simpler and cleaner, and think it is actually more approachable than the javascript way, because the difference between '.' and ':' or '\' is conceptually simpler than all the rules behind 'this' in javascript.
Programming in Lua explains ':' in http://www.lua.org/pil/16.html , and probably has a better explanation that I wrote :).