Re: Is intellisense features integration in Emacs technically possible?

[David Engster <deng@randomsample.de>]

Dmitry Gutov writes:
> David Engster <deng@randomsample.de> writes:
>
>>> Writing a C++ parser and semantic analyzer from scratch requires several
>>> man-years of work for world-class compiler writers.
>>
>> You don't need a full parser. For providing completions, it is
>> sufficient to parse only a small subset of the code (declarations, most
>> importantly).
>
> You may not have to parse every line of code, but you should be able to, no?
>
> Otherwise, how would you know which type the variable at point has,

By scanning the function's body for local variable declarations, and
simply ignore everything else. The C++ grammar simply has a bunch of
pretty generic expression rules without any actions, so we can skip over
the uninteresting stuff.

So yes, I wasn't specific enough: technically, we do parse function
bodies. But practically, we ignore most of it.

Of course there's a drawback that we don't fully parse the body - we
might get the local context wrong, for instance. But at least from my
experience it's working very well.

> or the return type of the method it calls

By parsing the declaration of the method.

-David