Waldemar Horwat wrote: > Mark S. Miller wrote: [Kona 15.3.4.5] >> 11. If the [[Class]] property of /G/ is *"Function"*, then >> 1. Get the *length* property of /G/. >> 2. Let /L/ be Result(11a) minus the length of /A/.
[These substeps are actually labelled a. and b.] > What does "minus" mean here? Result(11a) could be anything. The 'length' property of a built-in object with [[Class]] "Function" is not Writable or Configurable [Kona 15.3.5.1], so it must be equal to the number it was set to in either [Kona 13.2 step 7] or [Kona 15.3.4.5 step 11c or 12], which are the only places where built-in objects of [[Class]] "Function" are created (and [[Class]] cannot be changed after creation). But that should be explained in a NOTE section. Caveat: [section 15] # The value of the [[Class]] property of a host object may be any value, # even a value used by a built-in object for its [[Class]] property. So any random host object might have [[Class]] "Function" (which is a bug). If that is the case, all bets are off (and in that case steps 11 and 15 of the 'bind' algorithm are broken anyway -- for example, the 'length' or 'prototype' properties of G might not exist). Incidentally, the following sentence in section 15: # Unless specified otherwise, the [[Class]] property of a built-in # object is "Function" if that built-in object has a [[Call]] # property [...] is misleading because: # The value of the [[Class]] property is defined by this specification # for every kind of built-in object. i.e. there is no default for [[Class]] in the case of built-in objects. That is what allowed me to make the above assertions for built-in objects, otherwise I'd have had to read the entire spec rather than just searching for "Function". The sentence that implies that there are defaults for [[Class]] should be removed. -- David-Sarah Hopwood _______________________________________________ Es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
