[cffi-devel] Error with translate-to-foreign

[Greg Pfeil]

If I change the foreign-alloc to this, things seem to be alright:

(foreign-alloc :pointer
                :initial-contents (mapcar (lambda (list)
                                            (translate-to-foreign list
                                                                  
'string-list))
                                          value)
                :count (1+ (length value)))

Here I'm manually doing the nested translation, but I would have 
figured this was done for me just fine.

On Feb 23, 2006, at 4:36 PM, Greg Pfeil wrote:

> This is using the latest darcs cffi on SBCL 0.9.5 ...
>
> I have a list of lists of strings and have created the translations 
> below (the arrays end up null-terminated):
>
> (defctype string-list :pointer)
> (defctype string-lists :pointer)
>
> (defmethod translate-to-foreign (value (type (eql 'string-list)))
>   (let ((foreign (foreign-alloc :string
>                                 :initial-contents value
>                                 :count (1+ (length value)))))
>     (setf (mem-aref foreign :pointer (length value)) (null-pointer))
>     foreign))
>
> (defmethod translate-to-foreign (value (type (eql 'string-lists)))
>   (let ((foreign (foreign-alloc 'string-list
>                                 :initial-contents value
>                                 :count (1+ (length value)))))
>     (setf (mem-aref foreign :pointer (length value)) (null-pointer))
>     foreign))
>
> I get an error on the call to t-t-f for string-list, because the value 
> is a pointer and not a sequence. If I change the foreign-alloc type to 
> :pointer instead of string-list, it compalains that ("foo" "bar") is 
> not a pointer (which makes sense).
>
> So, using 'string-list seems to try to double-convert (which I don't 
> expect), :pointer seems to not convert at all (which I do expect). So, 
> any idea what I'm doing wrong?
>
> Here's the error:
>
>   0: (LENGTH #.(SB-SYS:INT-SAP #X082CCA70))
>   1: ((SB-PCL::FAST-METHOD CFFI:TRANSLATE-TO-FOREIGN (T (EQL (QUOTE 
> PRODUCT-DISC
> OVERY::STRING-LIST)))) #<unavailable argument> #<unavailable argument> 
> #.(SB-SYS
> :INT-SAP #X082CCA70) #<unavailable argument>)
>   2: ((SB-PCL::FAST-METHOD CFFI::TRANSLATE-TYPE-TO-FOREIGN (T 
> CFFI::FOREIGN-TYPE
> DEF)) #<unavailable argument> #<unavailable argument> 
> #.(SB-SYS:INT-SAP #X082CCA
> 70) #<CFFI::FOREIGN-TYPEDEF PRODUCT-DISCOVERY::STRING-LIST>)
>   3: (CFFI::MEM-SET #.(SB-SYS:INT-SAP #X082CCA70) #.(SB-SYS:INT-SAP 
> #X082CD488)
> PRODUCT-DISCOVERY::STRING-LIST 0)
>   4: (CFFI:FOREIGN-ALLOC PRODUCT-DISCOVERY::STRING-LIST 
> :INITIAL-ELEMENT NIL :IN
> ITIAL-CONTENTS (("ASIN" "B0002E3MRW")) :COUNT 2)
>   5: ((SB-PCL::FAST-METHOD CFFI:TRANSLATE-TO-FOREIGN (T (EQL (QUOTE 
> PRODUCT-DISC
> OVERY::STRING-LISTS)))) #<unavailable argument> #<unavailable 
> argument> (("ASIN"
>  "B0002E3MRW")) #<unavailable argument>)
>   6: ((SB-PCL::FAST-METHOD CFFI::TRANSLATE-TYPE-TO-FOREIGN (T 
> CFFI::FOREIGN-TYPE
> DEF)) #<unavailable argument> #<unavailable argument> (("ASIN" 
> "B0002E3MRW")) #<
> CFFI::FOREIGN-TYPEDEF PRODUCT-DISCOVERY::STRING-LISTS>)
>
> _______________________________________________
> cffi-devel mailing list
> cffi-devel at common-lisp.net
> http://common-lisp.net/cgi-bin/mailman/listinfo/cffi-devel