Are there any languages with "lateral" assignment operators?

Question

I don't know a really good name for what I'm talking about, but, most programming languages use a syntax for assignment statements something like this:

(variable) (assignment operator) (expression)

And some have some special assignment operators, such as var1 += var2 which is equivalent tovar1 = var1 + var2.

My question is basically, is there any language that would treat += like above, but also have an =+ operator so that var1 =+ var2 would be equivalent to var2 = var2 + var1?

Essentially, are there programming languages with "mirrorable" assignment operators, so that the variable on the right is what gets assignment a new variable (as opposed to the one on the left)?

Edit:

I suppose a much better example of what I'm referring to would be a language in which you can have both (variable) (assignment operator) (expression) and (expression) (assignment operator) (variable) as valid statements.

Answer 1

Authors of programming languages usually try to keep their language as simple as possible, without any unnecessary redundancy. So having any kind of two-side evaluation is redundant and unnecessary. It will only make the language specification 20 pages longer. I think there is no language with this feature.

By the way, your "grammar" (syntax rules) is not clear. What if someone writes

var x = 3, y = 2;
x = y;

By the way, Pascal has a "direction" of assignment. Actually, you can write your code as

var x = 3, y = 2;
x := y;
y =: x;

and write your own simple preprocessor for that, but again, I think it is just a complication of "clean" language.

Answer 2

What you propose is just a way to make code harder to read. There is no value in having a =+ operator if it's just synthatic sugar for writing your variables in a different order. But since you're into this weird stuff, you would surely love languages like Befunge and Piet, which, in a somewhat twisted way, do support that.

Answer 3

Some COBOL instructions are like this. E.g. ADD B TO A is the equivalent of "A += B" in other languages.