の with ステートメント

kuzha

をどうするか考えるために Ecma-262 を読んでみた。

The production WithStatement : with ( Expression ) Statement is evaluated as follows:
1. Evaluate Expression.
2. Call GetValue(Result(1)).
3. Call ToObject(Result(2)).
4. Add Result(3) to the front of the scope chain.
5. Evaluate Statement using the augmented scope chain from step 4.
6. Let C be Result(5). If an exception was thrown in step 5, let C be (throw, V, empty), where V is the
exception. (Execution now proceeds as if no exception were thrown.)
7. Remove Result(3) from the front of the scope chain.
8. Return C.

Standard ECMA-262

Expression 計算してその値をオブジェクトに直してスコープチェインの一番手前に置いてから Statement を評価するのか。