Re: Lua and composition

[Dirk Laurie <dirk.laurie@...>]

2017-03-01 15:11 GMT+02:00 Soni L. <fakedme@gmail.com>:
>
Apropos [2] http://lua-users.org/lists/lua-l/2016-04/msg00184.html
There is a typo in the original, so just read here.

> I mean, do you want arguments about the order the arguments
> should show up in? Because there are just as many arguments for
>
> x:y:z() -> x.y.z(x,x.y)
>
> as there are for:
>
> x:y:z() -> x.y.z(x.y,x)
>
> Here's how the latter is better:
>
> local x = {}
>
> x.y = {}
>
> function x.y:z(obj)
>   assert(self == x.y)
> end
>
> x:y:z() --> In your variant, we get assertion failed,
>         --> With reverse order, the assertion passes.
>
> Your variant would probably be bad for composition.

No, it is purely a typographical issue. Instead of ":.",
two characters, I want the colon to be movable.

At present:

a.b.c(...)   -- no implied argument
a:b.c(...)   -- illegal
a.b:c(...)   --> a.b.c(a.b,...)

I want the illegal construction to become legal.

a:b.c(...)   -- a.b(a,...)

And in general, one colon allowed, and the object
found up to just before that colon is the one passed.

a.b.c:d.e.f(...) --> a.b.c.d.e.f(a.b.c, ...)
a.b.c.d:e.f(...) --> a.b.c.d.e.f(a.b.c.d, ...)

Unless I misread your post, that is what you mean too,
just different notation.