Just to add my two cents, I would like to let you remember that the arrow
syntax should not be viewn as the only way to avoid the 'return' statement
and the brackets. "function(x) x*x;" does the trick too, whithout
introducing any new keyword. To those that think that the arrow syntax is
easier to type because there's less characters to type, it may be
disappointing to notice it's not the case : "(x) -> x*x;" is only 5
characters shorter than the other form but :
- You don't beneficiate from autocompletion anymore (in most IDE, typing
'fun+TAB' brings up 'function' arlready)
- The '-' and the '>' characters are more complex to type (on my
keyboard, both then - and the > char requires me to move my hand away from
its standards position, and the time it takes to type ' -> ' equals or is
more important than the time I need to type 'function' in *full* word, which
I usually don't need to).
- The syntax is less clear. CSharp originally introduced something like
that in the past, and I never liked the syntax. (It's to notice that the
VB.NET language later implemented the lambda feature using the "Function(X)
X*X" syntax). Okay, if I could really choose, I would prefer the "@(x) x*x;"
syntax, which is already implemented "as-is" in other scripting languages
such as MatLAB (but I already hear the concerns about other possible usages
of the @ sign).
- It introduces ambiguities in the code (Sample: var z = (x) -> x || y)
Regards,
François
-----Message d'origine-----
From: Brendan Eich
Sent: Saturday, May 07, 2011 3:39 AM
To: Peter Michaux
Cc: es-discuss@mozilla.org
Subject: Re: arrow syntax unnecessary and the idea that "function" is too
long
On May 6, 2011, at 5:04 PM, Peter Michaux wrote:
The only possible category is "be a better language" but the arrow
syntax won't make JavaScript a better language for complex
applications or libraries in comparison to any other kind of
JavaScript code.
Usability is always on the top three lists of programming language success
factors. 'function' and 'return' are too long.
I would argue that the arrow syntax will make
JavaScript a worse language anyway as there are already perfectly good
forms using the "function" keyword now.
Eight characters is at least six too many.
We don't need new syntax and
we don't need multiple ways to do the same thing just for the sake 6
Wrong, 14. You are not counting 'return'.
characters. Please keep JavaScript simple.
Sorry, this is a bogus argument. "Simple" does not mean "fewest productions
in all possible grammars" or "fewest ways of saying any given sentence."
That is simpler by some measures, more complex by others. In particular,
writing and (lesser but still material) reading 'function' over and over is
not a win.
Consider the destructuring object shorthand: let {x, y} = pt; instead of let
{x:x, y:y} = pt;
Look at all the complex/subtle edge cases mentioned in the wiki page
about arrow function syntax. Do we really want to have that much
trickiness added to the language?
The wiki page is a work in progress. I have updates coming, which should
address the parenthesization burden. But again, you can use 14 characters if
you want. This is shorthand, and only shorthand. And usability counts, so
shorthands are in Harmony (e.g., destructuring)
Gzip is not the issue (although stats I've seen from Steve Souders show too
may scripts not being compressed at the Transfer-encoding layer). Human
usability is.
/be
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