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It is of course always "possible", after all its a mere matter of programming :)
And of course an instantiated class template is just a type, but what is the name of std::vector<int> and std::vector<A> so it can be looked up?
vector<int> and vector<A>, with scope being std (I think trailing scope delimiters are not saved in the scope string of TMTag, just intermediate ones).
Sorry Thomas, I was a little mean and laid a trap.
std::vector has a second parameter, which has a default value so its legal to omit it, but the type you will get from an accurate parser to store in TM will be the complete type which will be something like std::vector<int, std::allocator<int>> not just plain std::vector<int>. This is the type you see printed in g++ and clang++ error messages for template expansions, very messy.
So the way TM does a pure textual comparison of the prefix in the source code `std::vector<int>` simply won't work to find `std::vector<int,std::allocator<int>>`
It also won't work if there are spaces as I showed in a previous post `std::vector< int >` is perfectly legal C++ but won't match `std::vector<int>`. And before you ask, yes lots of code has the spaces so that nested angle bracket closes (as in my ...allocator<int>> above) look like > > not the >> operator. Being able to omit the space and not have it seen as a shift right operator is only a recent addition to the standard.
And for template functions declared as `template<class T>T& f(T& t){ return t<<1; }` they are used as simply `int a = f(1);` not an angle bracket in sight, and a textual comparison to find the declaration for a calltip isn't going to work because no such explicit declaration exists. So how can TM answer whats legal here `f(std::cout).` (answer all of std::ostream) versus here `f(1).` (answer nothing).
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Good point, the FT-Plugin API needs functions for goto declaration and goto definition. Unlike TM, the plugin can take language and scope rules into account when it answers, so you get the right declaration, continuing the theme above, where would you go to find the declaration of std::vector<int> ?
Certainly not the line:
std::vector<int> list_of_ints;
thats the declaration of `list_of_ints` but thats the only place that `std::vector<int>` exists in the code.
Ideally the header which defines std::vector<A> would be found (and maybe opened) right? Currently this isn't possible with TMTag (as var_type can only contain either vector<A> or vector<int>) but it shouldn't be too hard to make it work.
But now you are encoding language specific semantics into TM, and as I noted above its more complicated than just that example.
Please don't get the idea from simple examples posted here that they cover even a fraction of the craziness of languages (and not just C++ either, its simply the one I'm most familiar with).
Like adding a generic_type field which is set for each
template instance (containing vector<A>), then instead of looking up the decl of generic_type if it's not NULL, otherwise var_type.
Of course, the TMTags associated with vector<A> and vector<int> would have to provided by the ft-plugin too (maybe there needs to be a new TMTagType for vector<A> too).
And don't forget that when trying to look up `std::vector<int>::value_type` to see whats next, or to find the declaration, either Geany or TM has to parse it and break it into the elements `std`, `vector<int>` and `value_type`, ie has to know the language syntax for template specialisations and namespaces, `vector<int>` is not a legal name. And as I said before, that syntax varies between languages, so again you are encoding language specifics into Geany or TM.
And in a final real piece of evil C++ for the day, variadic templates with variable numbers of parameters (like C variadic functions with ...).
std::get<1>(std::make_tuple(1 ,std::string("abc"), 3)).size(
ok, lets lookup the return type of std::make_tuple http://en.cppreference.com/w/cpp/utility/tuple/make_tuple thats simple-ish and the type of std::get<1> http://en.cppreference.com/w/cpp/utility/tuple/get hmmmm
And yep its all completely legal and idiomatic C++ and totally static typed so should be no problem analysing it.
Sorry Colomban you didn't want see half the craziness of C++ I know :)
Of course moving the problem to plugin space doesn't mean the plugin can't use Geany facilities where their capabilities fit the requirement. But we should not try to expand Geany to handle all types of functionality.
Like your TM query interface, the plugins should answer the questions like "whats the autocomplete here", "what calltips are relevant here" with a flat list of data relevant to the question.
My TM query interface wants to return all matching tags, including those found by ft-plugins. Can this be done?
Only if your query plugin queries the FT plugin.
So that means
- My plugin contains code specifically for each known ft-plugin (i.e. not
the plugin API)
No, but the implementation inside Geany of the query interface that you have added in your PR may have to know to call the FT-plugin to answer the query, but the plugin using the query interface doesn't need to know about that.
- There needs to be a shared library which my plugin can use to call into
the other plugin
I'm not sure why you would need a third dll even if you were having to call the FT-plugin directly, you probably have to be passed its g_module though. But you shouldn't have to access the FT-plugin directly unless you are doing something Geany doesn't support.
- My plugin needs to know if and when to ask a ft-plugin
As I said unless you are asking a question Geany doesn't know how to answer, then you shouldn't need to.
This is not acceptable.
Be aware that as you say that, the alternative is for you to implement all those language specifics I mentioned above in your plugin itself.
Or are you saying Geany could provide a wrapper for this as Matthew suggested? That might be workable.
Yes, exactly. As Matthew said in a previous post, for each feature where a FT-plugin is involved the function inside Geany that provides that feature is going to have to have an if near the front that makes the decision if it uses the plugin or does it itself. So if your plugin uses that function you get the benefits of both implementations.
Cheers Lex
Best regards.
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