> I have no idea how to make sense of this. Maybe I should have used a different phrase. I meant that an expression consisting of a variable (e.g. "x") may be

> I have no idea how to make sense of this. Maybe I should have used a different phrase. I meant that an expression consisting of a variable (e.g. "x") may be evaluated as if it were a dynamically-dispatched function call (e.g. "x.valueOf()"), so even the most innocent-looking expression may contain hooks to which someone may have attached an effect. Even though JS is call-by-value, implicitly-called methods like "valueOf" allow values in normal form to act like thunks with arbitrary side-effects, which causes a dependence on evaluation order even for such innocent-looking expressions as "x".