On 17 September 2012 18:37, Luke Hoban lu...@microsoft.com wrote:
'let' is certainly not going to be faster than 'var' in any case
There is at least one very important counterexample to that claim: the
global scope. Assuming lexical global scope (as we tentatively agreed
upon at the last
On Sep 18, 2012, at 7:27 AM, Andreas Rossberg wrote:
On 17 September 2012 19:51, Allen Wirfs-Brock al...@wirfs-brock.com wrote:
On Sep 17, 2012, at 12:37 PM, Luke Hoban wrote:
These are good questions. Paul will be attending the TC39 meeting this
week, and can likely talk to specific
On 18 September 2012 13:41, Allen Wirfs-Brock al...@wirfs-brock.com wrote:
Yes but but there are fairly simple heuristics that approximate that result,
for example:
if no function calls dominate the initialization of x then TDZ checks will
never need to be made for x
Yes, except that in
some comments below
On Sep 16, 2012, at 9:35 PM, Luke Hoban wrote:
We've begun deeper investigations of implementation practicalities related to
let/const, and two significant performance concerns have been raised. I
think these both merit re-opening discussion of two aspects of the
From: Andreas Rossberg [mailto:rossb...@google.com]
On 17 September 2012 03:35, Luke Hoban lu...@microsoft.com wrote:
__Temporal dead zones__
As an experiment, I took the early-boyer test from V8 and changed 'var' to
'let'. In Chrome preview builds with 'let' support, I saw a
(Just one opinion)
I'm all in favor of function-level parse errors. This reminds me an article
of Ian Hickson where he wondered why, to the contrary of CSS, the ECMAScript
language didn't define a generic syntax defining a well-formed program
(tokens, parenthesis+brackets balance, ...) and
Agree with your points in reply to Luke, one clarification here:
Allen Wirfs-Brock wrote:
As stated above, let isn't the motivator for TDZ, it's const. Let could
easily be redefined to not need a TDZ (if that really proved to be a major area
of concern). So, you either need to argument
From: Allen Wirfs-Brock [mailto:al...@wirfs-brock.com]
On Sep 16, 2012, at 9:35 PM, Luke Hoban wrote:
As an experiment, I took the early-boyer test from V8 and changed 'var' to
'let'. In Chrome preview builds with 'let' support, I saw a consistent ~27%
slowdown. That is, the 'let is the
From: Brendan Eich [mailto:bren...@mozilla.org]
Allen Wirfs-Brock wrote:
As stated above, let isn't the motivator for TDZ, it's const. Let could
easily be redefined to not need a TDZ (if that really proved to be a major
area of concern). So, you either need to argument against const
On Sep 17, 2012, at 12:37 PM, Luke Hoban wrote:
These are good questions. Paul will be attending the TC39 meeting this week,
and can likely talk to specific details. High level though, we statically
eliminate the TDZ checks for references to 'let' within the same closure body
as the
2. The stated goal of 'let' is to replace 'var' in common usage (and if
this is not the goal, we should not be adding 'let').
There is actually some disagreement about that statement of the goal. The
goal of let is to provide variable that are scoped to the block level. That
is the
11 matches
Mail list logo
