array element assignment returns entire array

[StefanKarpinski]

julia> v = [1]
[1]

julia> v[1] = 2
[2]

This regression has been around for a long time. Not even sure when it was introduced, but it's really annoying.

[JeffBezanson]

Not a regression. This was always intentional.
In the repl at least you usually want to see the whole array after modifying it.

[StefanKarpinski]

This is a regression because we changed this for a long time. It's really, really broken behavior. I do not want to see the array after I assign. Assignment returns the RHS in every single language I can think of.

[JeffBezanson]

Actually, what the assign method returns is independent of what the syntax a[i]=x returns. Should we change all the assign methods, or let assign return whatever it wants and have the front-end arrange for a[i]=x to return x?

[StefanKarpinski]

I think having the front end arrange it is better for chained assignments. If it's based on what assign returns then you can have "accidental" conversions through various types instead of each one converting the RHS separately. Admittedly chained assignment is a bit sketchy, but it's also really common and convenient.

[JeffBezanson]

I agree. I'd rather do it that way.

[StefanKarpinski]

With immutable composites, chained assignment actually becomes a lot less sketchy — it's a harmless shorthand when the RHS is immutable.