On 03/16/2011 09:33 PM, bearophile wrote:
Andrei:
No need to blow out of proportion everything that serves a point.
You are right, but probably I am doing that because I see you nearly
deaf to the problems I see in Phobos usages of enforce().
It's not about me. Phobos has several contributors (including
non-committers) who could be receptive to such issues and proactive
about fixing them either in the language or the library.
There are only few places in which use of enforce (or checking in
general) slows things down.
I have hit some of such cases in my code, finding them through
profiling. At first I didn't expect Phobos functions to give those
problems :-(
There are indeed a few places in which using enforce makes things
slower. The principled approach to such things is not to blame enforce,
but to fix the compiler to allow such a simple and effective idiom.
Because I don't condone defining large exception hierarchies.
The WrongArgumentException I am talking about comes from a set of
less than about ten most useful exceptions, and I mean this hierarchy
to be flat, all of them come from Exception. So this is not a large
exception hierarchy.
You may want to add a DIP at
http://prowiki.org/wiki4d/wiki.cgi?LanguageDevel (possibly backed up by
a pull request) and discuss it here. There are always ten "most useful"
exceptions, except not all people think of the same ten.
but that's not an issue that is the charter of enforce or that
enforce prevents.
When you design a language and its standard library you have to keep
a balance between making things very easy but not good enough, and
very hard/fussy but better (see the simplicity of ddoc and D
unittests, ddoc is mostly OK, but unnittests are probably a bit too
much simple, they miss some essential features like a name). In my
opinion a standard library is meant to throw a bit better exceptions
than fully generic ones.
The rhetoric sounds great. Now let's see a concrete proposal.
It makes the standard library writers productive.
enforce() has clearly some disadvantages. I believe the very small
convenience it brings to Phobos writers is not enough to justify its
usage in many cases.
enforce is convenient and leads to short, simple, and correct functions.
Small and large teams have used and are using similar artifacts in
codebases at three other companies I worked and work for. On what basis
are you assessing the amount of convenience it brings?
One of such cases is inside iota(), where I suggest to replace its
usage with a if+throw to allow iota() to be usable in pure functions
too.
I'd almost suggest using bugzilla.
Hoping less and doing more would be great.
You are right. I am sorry. I am trying to help, even if I am not doing enough.
If anything please don't go again the sheepish route. If you were really
sorry you wouldn't have started with something to be sorry about - and
in what tone - in the first place. After the initial self-righteous and
over-confident stance, it always seems awkwardly insincere. Wouldn't a
simple and honest discussion be best? Framing everything as a diatribe
against a two-line function is just ungainly.
Andrei
