[kijin]

An object-oriented version (assuming mutable strings) might be:

    A$.REP("123", 4, 0)

So the syntax is weird, but the concept isn't totally unusual.

[pedasmith]

Exactly. It's a perfectly reasonable concept with a completely outlandish syntax. I don't know of any current programming language where the RHS of an assignment will even know what the LHS is.