Re: [q-lang-users] Memory management in libqint

[Albert G. <Dr....@t-...>]

John Cowan wrote:
> The comments in qint.h saying which arguments and results belong to Q
> (that is, the calling application must not free them) and which must
> be freed by the application are incomplete.  For qexprs, I can control
> Q's behavior by using the qnewref, qfreeref, and qdispose functions,
> but for other argument types I need more details.

This isn't explicitly mentioned in the qint.h file, but all char* 
parameters flagged as const belong to the caller and are not modified by 
the API functions in any way. This should resolve all the "unknowns" in 
your list. The only actual error I spotted is here:

> 	qget* family: argument string belongs to Q

No, the strings passed are const char* so they belong to the caller.

> 	Unicode helpers: no information

You shouldn't have to wrap the unicode helper functions in your Scheme 
interface, these are just provided as convenience functions to be used 
if you need to convert/from Q's UTF-8 string encoding when constructing 
or inspecting string qexprs (if your Scheme dialect has UTF-8 strings 
then no conversion will be necessary). Anyway, the const char* args of 
these functions, again, belong to the caller and are not modified, and 
the returned result strings are dynamically allocated and have to be 
freed by the caller (unless, of course, the result string is to be 
passed to qmkstr() and thus becomes owned by the Q interpreter).

HTH,
Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikinformatik.uni-mainz.de/ag