A bit confused by B.3.2 - Web Legacy Compatibility for Block-Level Function Declarations

[John Lenz]

Or a link to the discussion that led to the content of this section?


On Thu, Jun 5, 2014 at 9:51 AM, John Lenz <concavelenz at gmail.com> wrote:

> Is there any place that has some concrete examples of the different cases
> we are trying support with this section (and whether the function is block
> scoped or not in each case)?
>
>
> On Thu, Jun 5, 2014 at 9:45 AM, Allen Wirfs-Brock <allen at wirfs-brock.com>
> wrote:
>
>>
>> On Jun 5, 2014, at 8:14 AM, John Lenz <concavelenz at gmail.com> wrote:
>>
>> On Wed, Jun 4, 2014 at 8:52 PM, Allen Wirfs-Brock <allen at wirfs-brock.com>
>> wrote:
>>
>>>
>>> We don’t want to leave the meaning of function declarations in blocks
>>> completely unspecified, as in ES1-5 as we; know there are legacy
>>> compatibility requirements for them.  So, we need to have some semantics
>>> for them.  The easiest way to provide any semantics is to simply use the
>>>  same  block scoping semantics that is used in strict mode (slight
>>> augmented to  over the legacy intersection semantics).  That actually
>>> limits the refactoring hazard because as long as you have no code that
>>> depends upon the legacy intersection there is no difference between the
>>> function in block strict and sloppy semantics.
>>>
>>>
>> It is the slightly augmented part that seems to be the problem here.  It
>> is (1) very confusing and (2) creating the refactoring hazard: introducing
>> a function of the same name in a different block breaks the scoping.  I
>> would be happy to be misunderstanding that section.
>>
>>
>> Nobody likes the augmented part, but it’s what is necessary for web
>> legacy compatibility.
>>
>> Allen
>>
>>
>
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