Re: [Chicken-users] easyffi virtual=0 methods

[felix winkelmann]

On 3/12/07, Carlos Pita <address@hidden> wrote:
> I was thinking a bit more about this and concluded that it wouldn't be
> possible to derive from an abstract C++ class in tinyclos anyway
> (because of the impossibility of constructing an instance of that class
> from anywhere but a subclass C++ constructor). So I decided to subclass
> the problematic class from C++ providing default dummy implementations
> for the abstract methods. Now I must call the (non-default) constructor
> of the subclass and I'm having trouble with the easyffi parser for the
> syntax: ctor(...) : base-ctor(..) {}. One thing I can do to solve this
> is to put the definition inside a #> <# block and the declaration inside
> a #>? <# block (instead of putting the definition once in-between #>!
> <#). But in any case, the easyffi documentation in
> http://galinha.ucpel.tche.br:8080//easyffi#foreign-include-path states
> that the grammar supports calling base constructors:
>
> CONSTRUCTOR = ["___callback" | "___safe"] ["explicit"] ID "(" ARGTYPE
> "," ... ")" [BASECONSTRUCTORS] [CODE]
>
> Specifically, the problematic line is:
>
>   ScmStkFrames( unsigned int nFrames, unsigned int nChannels, bool
> interleaved ) : StkFrames(nFrames, nChannels, interleaved) {}
>
> And the reported error is:
>
> Error: during expansion of (foreign-parse ...) - unexpected tokens: ((op
> ":") (id "StkFrames") open-paren (id "nFrames") comma (id "nChannels")
> comma (id "interleaved") close-paren (scope))

This works for me:

#>?
class ScmStkFrames {
ScmStkFrames( unsigned int nFrames, unsigned int nChannels, bool
interleaved ) : StkFrames(nFrames, nChannels, interleaved) {}
};
<#


Can you provide a complete example?


cheers,
felix