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

[Allen Wirfs-Brock]

On Jun 4, 2014, at 2:43 PM, John Lenz <concavelenz at gmail.com> wrote:

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> How does someone write code to make sure it doesn't fall into legacy semantics?  Unless, I misunderstand these rules seem like a refactoring hazard.  It would seem better to say: sloppy mode === no block scoped function declarations.  strict mode === block scoped function declarations.

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.  

Allen