Variable scope and order of parsing vs. operations: Assignment in an “if”

Question

My understanding is that the if statements at the end of the line are evaluated before the code at the front of the line:

\'never shown\' if (fa         


        

Answer 1

My guess is that the order of parsing is different from the (logical) order of execution. In particular, given

array << error if (error = some_function)

Then logically, execution should go something like

1. call some_function
2. if error not defined, define error
3. assign return value of some_function to error
4. evaluate if
5. if if evaluates to true, append value of error to array

However, parsing wise (assuming typical LR parser), it goes

1. Got token array (identifier). Is this defined? Yes. Is it a variable? Yes.
2. Got token << (operator). Does array respond to <<? Yes (otherwise, output "undefined method" error).
3. Got token error (identifier). Is this defined? No. Output "undefined local variable or method".