Ary Borenszweig Wrote: > Walter Bright wrote: > > In my discussions with companies about adopting D, the major barrier > > that comes up over and over isn't Tango vs Phobos, dmd being GPL, > > debugger support, libraries, bugs, etc., although those are important. > > > > It's the IDE. > > > > So, while I'm not going to be writing an IDE, I figure that dmd can > > help. dmd already puts out .doc and .di files. How about putting out an > > xml file giving all the information needed for an IDE to implement > > autocompletion? There'd be one .xml file generated per .d source file. > > > > What do you think? > > What I think is that even with an xml representing the parse tree (maybe > with some semantic stuff resolved) it'll be still incomplete for a real > IDE (the kind of thing users expect from an IDE). You can see this > video, for example: > > http://www.youtube.com/watch?v=KQbTT605ags > > So you have: > > --- > module one; > > class Foo(T) { > static if (is(T == class)) { > T property; > } else { > T someMethod() { return T.init; } > } > mixin(guessWhat!(T)()); > } > --- > > You want to define an xml for that module that'll help IDEs. Can you > think what it'll look like? > > Now the user writes in another module: > > class Bar { > } > > void x() { > auto foo = new Foo!(Bar)(); > foo. <-- what does the IDE do here? > } > > Now, the correct thing for the IDE to do is to suggest the field "Bar > property". How can the IDE do that just with an xml? It can't. It need > to perform some kind of semantic anlysis to Foo's argument to see if > it's a class, match the static if in the template, replace template > parameters, etc. It also needs to evaluate the string mixin. > > Of course you could say "Bah, just show all the declarations inside the > template in the autocomplete", but that's wrong. That'll lead to files > that don't compile. You could ommit supporting autocompletion or other > nice features, but that's exactly the big features of D. If you don't > support that then it's like using Java or C# from within the IDE: you > could use the advanced features but the IDE won't help you. And in your > discussions with companies adopting D, I'm sure they were talking about > great IDEs like JDT Eclipse or Visual Studio, not just some tool that > helps you a little but not anymore when things get interesting. > > Oh, and you need to have some kind of semantic analysis to know the type > of "auto foo". Again, maybe the IDE can be dummy and see "auto foo = new > Foo!(Bar)" and say "ok, foo's type is Foo!(Bar)", but then you have: > > auto b = foo.property; > b. <-- and here? > // remember "property" is templated and depends on static analysis > // or the IDE could need to resolve alias this or other things > > So... my opinion (like some others, I see) is to either ask things to > the compiler directly (but here the compiler lacks some info, like exact > source range positions), or to have a compiler (not a full-blown one, > just the front-end) built into the IDE, and that's what Descent is. > Unfortunately Descent is sometimes slow, sometimes buggy, but that's > normal: just a few people develop and maintain it (so I can see a > similarity with dmd here, where each day I see two or three new bugs > reported). If more people were into it, more unit tests were written > into it and, most of all, more people would use it, it'll get better. > > Another problem that people see in Descent (maybe also JDT Eclipse and > Visual Studio0 is that it's huge, it consumes a lot of memory and they > don't want to open a huge tool just to hack some lines. My answer is: > memory performance can be improved (but not a lot), but since an IDE is > a huge tool it requires a lof from the computer. And an IDE is not meant > to be used to hack some lines, it's meant to help you write big project, > huge projects without getting lost in the amount of code. > > So my bet would be to start supporting an existing IDE that integrates a > compiler into it. Updating it is easy: just port the diffs between DMD > versions. It's a huge job for one or two people, but if a lot of people > were involved it's not that much. Of course I'd recommend you to try > Descent since I'm one of it's creators and I do believe it can get > pretty good. :-)
A lot of people like me have been waiting for a good IDE for D for a long time. In the field of IDE of D, Descent has already have a good baseline. So I think the community should put more effort in make Descent better, other than create another IDE. For this reason, I think Ary Borenszweig's opinion on in which way can dmd help in building a better IDE may be more valuable than Water's, for he is the author of the currently most advanced IDE of D. Sorry for my poor English.
