Now you are forgetting the argument that TCP-conforming block-lambdas
*should* look quite different from ...(params) {body} functions. This
implies that shorter function syntax ought to follow the (params) {body}
plan.
/be
Herby Vojčík <mailto:[email protected]>
January 19, 2012 11:40 AM
Brendan Eich wrote:
Axel Rauschmayer <mailto:[email protected]>
January 19, 2012 9:31 AM
Rationale: wouldn’t freezing by default be OK for 98% of the cases? If
you want anything else, you can use a traditional function. Then the
above syntax as the only function shorthand would be OK.
First, #(params) { body } was proposed by Arv and Alex:
http://wiki.ecmascript.org/doku.php?id=strawman:shorter_function_syntax
Arv and Alex feel strongly that the shorter function syntax (anything
shortening 'function' syntax) must not freeze by default.
Well, if #(x, y) {x+y} is not good because of # is used for freezing
and freezing is not good (it is not, metadata is good argument for
that), and if something-like-lambda-block is ok, some variation of
lambda-block could be the shorter replacement for functions. These
come to mind:
{*a, b* a+b}
{/a, b/ a+b}
{^a, b^ a+b}
{%a, b% a+b}
and there is still more infix operators...
maybe even {`a, b` a+b} if it does not create conflict in this context.
/be
Herby
Brendan Eich <mailto:[email protected]>
January 19, 2012 11:27 AM
Axel Rauschmayer <mailto:[email protected]>
January 19, 2012 9:31 AM
Rationale: wouldn’t freezing by default be OK for 98% of the cases? If
you want anything else, you can use a traditional function. Then the
above syntax as the only function shorthand would be OK.
First, #(params) { body } was proposed by Arv and Alex:
http://wiki.ecmascript.org/doku.php?id=strawman:shorter_function_syntax
Arv and Alex feel strongly that the shorter function syntax (anything
shortening 'function' syntax) must not freeze by default.
There was lack of clarity about whether completion value as implicit
return value was part of the proposal. If so, controvery, since there
is a completion value leak hazard. TC39 seems to agree the solution
there is something with different look & feel, such as block-lambdas.
But, making a one-char grawlix shorthand for 'function' while still
requiring 'return' is not considered enough of a shorthand. A possible
cure here is to support an alternative body syntax: #(params) expr.
However, this inverts precedence if done naively. It also runs into
trouble trying to prefer an object literal over a block statement.
I've worked on both of these in the context of
http://wiki.ecmascript.org/doku.php?id=strawman:arrow_function_syntax
This superseded shorter_function_syntax, but ran into grammatical
issues that have vexed it.
But notice that throughout this, no one advancing a proposal advocated
freezing by default. JS developers use function objects as mutable
objects. Not just to set .prototype, also to decorate with ad-hoc and
meta-data properties. Freezing is not wanted by default.
I agree that for block-lambdas it's easier to say "freeze by default".
For merely "shorter function syntax", no. Functions are mutable
objects by default in JS. This matters for minifiers, which may not be
able to see all the mutations but would love to use shorter syntax for
'function' syntax, blindly.
/be
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Axel Rauschmayer <mailto:[email protected]>
January 19, 2012 9:31 AM
Rationale: wouldn’t freezing by default be OK for 98% of the cases? If
you want anything else, you can use a traditional function. Then the
above syntax as the only function shorthand would be OK.
--
Dr. Axel Rauschmayer
[email protected] <mailto:[email protected]>
home: rauschma.de <http://rauschma.de>
twitter: twitter.com/rauschma <http://twitter.com/rauschma>
blog: 2ality.com <http://2ality.com>
Brendan Eich <mailto:[email protected]>
January 19, 2012 9:25 AM
I'm not sure what you mean. I proposed this a while ago ("Harmony of
My Dreams") but we don't want frozen by design, and without the # the
result is ambiguous without restricted productions, and hazardous on
that account.
The idea that any grawlixy preifx will do is false. Hash is wanted for
consistent freeze/seal prefixing. Arrow is better and putting it at
the front solves the grammar problems with arrow function syntax as
current drafted.
/be
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Axel Rauschmayer <mailto:[email protected]>
January 19, 2012 12:06 AM
Couldn’t one always freeze such a function shorthand and then get
syntax such as:
#(x, y) { x + y }
--
Dr. Axel Rauschmayer
[email protected] <mailto:[email protected]>
home: rauschma.de <http://rauschma.de>
twitter: twitter.com/rauschma <http://twitter.com/rauschma>
blog: 2ality.com <http://2ality.com>
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