Syntax confusion with **

[dronir]

I was porting some Python code into Julia and forgot to change a Python exponentiation with ** into Julia's ^. I didn't notice this at first and the program ran ok, but was wondering why my results were weird.

After some examination, I realized that even though a**b gives a syntax error in Julia, (a)**(b) with the parenthesis is evaluated as a*b. This is because *(x) is a valid function call and *(x) == x so it's parsed as (a)*(*(b)). Not sure if this needs fixing, but it did cause some confusion, which was largely my own fault for not converting the syntax properly.

[StefanKarpinski]

This should definitely raise a helpful error (e.g. "power is written as x^y") because this is going to bite a lot of people. We could conceivably support x**y as an alternate syntax for x^y, but I'm hesitant to do that because it's adding unnecessary syntax — and I've always disliked that syntax for exponentiation.