CODEWITHSUNDEEP
pythonswig
Andrew Miller
Andrew Miller

Reputation: 143

Handling arrays of structures in SWIG

I am trying to wrap a C function that requires an array of structures to be passed to it.

The function definition in my .i file is:

extern HRESULT WINAPI ScriptItemize(
const WCHAR           *pwcInChars,    // In   Unicode string to be itemized
int                   cInChars,       // In   Codepoint count to itemize
int                   cMaxItems,      // In   Max length of itemization array
const SCRIPT_CONTROL  *psControl,     // In   Analysis control (optional)
const SCRIPT_STATE    *psState,       // In   Initial bidi algorithm state (optional)
SCRIPT_ITEM           *pItems,        // Out  Array to receive itemization
int                   *pcItems);      // Out  Count of items processed (optional)

The structs SCRIPT_CONTROL, SCRIPT_STATE and SCRIPT_ITEM have all been previously defined in the .i file.

I can indicate that pcItems is a return values by including the following lines:

%include <typemaps.i>
%apply int *OUTPUT {int *pcItems};

However, attempting to do the same with with pItems:

%apply SCRIPT_ITEM *OUTPUT {SCRIPT_ITEM *pItems};

I get this warning:

Can't apply (SCRIPT_ITEM *OUTPUT). No typemaps are defined.

How do I indicate that pItems is a return value?

Also, how do I create the array of SCRIPT_ITEM structures from within Python?

Upvotes: 1

Views: 888

Answers (1)

Andrew Miller
Andrew Miller

Reputation: 143

I've managed to find the way to do this by changing my .i file as follows:

%include <carrays.i>

%array_class(SCRIPT_ITEM, SCRIPT_ITEM_ARRAY);

extern HRESULT WINAPI ScriptItemize(
const WCHAR           *pwcInChars,    // In   Unicode string to be itemized
int                   cInChars,       // In   Codepoint count to itemize
int                   cMaxItems,      // In   Max length of itemization array
const SCRIPT_CONTROL  *psControl,     // In   Analysis control (optional)
const SCRIPT_STATE    *psState,       // In   Initial bidi algorithm state (optional)
SCRIPT_ITEM_ARRAY     *pItems,        // Out  Array to receive itemization
int                   *pcItems);      // Out  Count of items processed (optional)

Upvotes: 2

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