Re: [Opencxx-users] parse error on valid code

[Stefan S. <se...@sy...>]

Grzegorz Jakacki wrote:

>> Ah, now I understand again ! So, the solution is to add a type dictionary
>> ('Environment' ?) to the Parser and then let the 'isTypeSpecifier' use 
>> that
>> instead of just detecting built-in types. Right ?
> 
> 
> For many cases this should work. However in general it will not.

understood. Putting a type dictionary right into the parser means
that the type recovery can't be done in a second pass, but instead
has to be done as soon as a new type declaration has been detected.

The separation between parser and mop libraries doesn't make sense
in that context any more...

> The top-level environment is maintained by ClassWalker. Driver in the 
> main loop runs Parser::rProgram() and feeds the obtained AST into 
> ClassWalker. Parser::rProgram() returns AST representing one top-level 
> construct (definition or declaration), so one iteration analyzes one 
> top-level construct. Only when ClassWalker traverses the AST, the 
> information about types defined in it are stuffed into Environment.

what does 'ClassWalker' do ? The name suggests it is only inspecting
class definitions, but not you are suggesting it deals with arbitrary
type recovery.

> This is fair enough when there is no namespaces or nested templates. 
> However, if top-level construct is a namespace, then Environment does 
> not have a clue about anything defined in it until it is fully parsed.

hmm, I don't understand the design of Environment et al. yet. Why doesn't
it 'have a clue' until it is 'fully parsed' ? In the example

namespace Foo
{
typedef int Int;
typedef std::vecor<Int> IntVector;
}

Shouldn't it know 'Int' when it sees the typedef for IntVector ?

> I don't think there is an easy and complete solution. I have one 
> solution in mind, but it is neither cheap, nor easy.

Please document the current design and the solutions you envision. It will
help a lot to work out the remaining issues to make opencxx a very powerful
tool that supports all standard C++.
More and more people use synopsis, and the bug reports about parse errors
I get become more and more sophisticated, indicating that it becomes more
and more important to make the parser work correct not only for the most
used C++ features, but really covering the full standard.

Regards,
		Stefan