On 7/17/2014 1:44 PM, Justin Whear wrote:
On Thu, 17 Jul 2014 12:28:33 -0700, Andrei Alexandrescu wrote:
On 7/8/14, 2:31 PM, Brian Schott wrote:
http://wiki.dlang.org/DIP65
tldr: There are parser and specification bugs and I want to fix them.
It will break some poorly-written code, but I think I can automate the
upgrade process.
I vote we reject this DIP. It has clear appeal but there's also the
issue with putting currently correct code on a deprecation path, with no
obvious win in quality.
I think Walter's fix eliminates the problem during the semantic pass
even though there's a grammar ambiguity. It's a judgment call, and by
definition someone has to make it.
Andrei
My understanding (and this is supported by hard numbers from Brian's
survey of Phobos), is that Walter's proposal will perpetuate a bad design
choice that is rarely if ever used (never in Phobos) in favor of
deprecating a better syntax that is used (in Phobos and elsewhere).
That is to say, we have hard numbers to prove that Walter's fix will
deprecate currently working code while leaving us with the less-desirable
syntax, while Brian's proposal will transition us to the more desirable
syntax without breaking code written in the currently used idiom.
And, as Brian pointed out[1], the current idiom of `catch (Throwable)`
_is described_ in the spec, albeit not in the formal grammar. Ergo,
Walter's fix also deprecates currently-working, correct syntax. Given
that both are correct, but one is nearly completely unused and error
prone, I vote yes on this DIP.
[1] http://forum.dlang.org/thread/[email protected]?
page=2#post-zsvbxhtbwevsrrflxzyr:40forum.dlang.org
Did you see my response?
I suggested recognizing in the parser:
( Identifier )
as a special case, in addition to using Parser::isDeclaration(). Gradually we
can turn that special case into a warning, then deprecation.
