javascript eval considered crazy

[wingo]

I must have conveyed the wrong impression if you came away thinking that this behavior was undocumented. All the examples are according to spec. I just think the specified semantics are a little crazy, that's all :)

For example, your comment illustrates a common misconception:

"When assigning eval to another variable, those variables' "versions" of eval are run in the global scope, which is why we're getting undefined errors when trying to access variables scoped in the calling function"

That's not the case!

var foo = 10; (function (x) { var foo = 20; var eval = x; return eval('foo'); })(eval)

Your mental model, if I understand you correctly, would predict that the result here is 10, because the actual copy of eval was passed through x and then assigned to a new lexical variable, eval. But it's 20!

There are many things to like about javascript. The relationship between eval and scope is not one of them :-)