In this case, it's more complicated then a single with-destructor scope,
because I use the destructors to call libyaml's destroy function on the
struct, so that the same memory can be reused between the calls to libyaml
for this struct. So I really need to destroy it right away before the next
call the libyaml, hence the nested with-destructors.
I could allocate new memory for those structs every time and destroy them
only at the end of the parsing. But in most cases, only one struct is
needed at a given time, so I thought reusing them was a good thing.
Jon
On Tue, Mar 18, 2014 at 12:21 PM, Björn Lindqvist <bjou...@gmail.com> wrote:
> Hi Jon,
>
> 2014-03-17 21:57 GMT+01:00 Jon Harper <jon.harpe...@gmail.com>:
> > Hi list,
> > I am working with libyaml, a C library to parse yaml docs. Some libyaml
> > functions give string results by malloc'ing memory and giving back
> pointers
> > to those strings in a struct. They then require the caller to call a
> libyaml
> > "destroy" function on the struct that frees the strings.
> >
> > I would like to make a deep copy of the manually managed struct to a
> garbage
> > collected struct so that I can keep some data after I called the libyaml
> > destroy function and not worry about freeing it. Does anyone know how to
> do
> > this simply ?
>
> Let me preface this by saying that I'm far from an expert neither on
> libyaml or factor... But this is what I think I've figured out about
> how alien memory management works.
>
> What I think you are doing wrong is worrying to much about freeing the
> memory you are allocating. The ?scalar-value word is only an
> intermediate step in the doc parsing process. Since the yaml> words
> body already is wrapped in a with-destructors block, and it is the
> main entry point for your parser, you don't need to call
> with-destructors anywhere else.
>
> Just remember to pair every allocation (or resource acquisition) with a
> &destructor word (which you already are doing) and factor should work
> it out fine.
>
>
> --
> mvh/best regards Björn Lindqvist
>
>
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