move vips_operation_set_valist_optional() to obj

now a method on object, vips_object_set()

TODO

@@ -1,7 +1,12 @@
-- make vips_operation_set_valist_optional into a general thing on vipsobject
+- have made vips_operation_set_valist_optional into a general thing on 
+  vipsobject
 
 	vips_object_setv( VipsObject, va_list list );
 
+  needs docs
+
+
+
 - should
 
 	vips_image_new_mode ()
@@ -31,8 +36,6 @@
 - update "how it works" to note we are now fully-functional ... there's
   vips_image_write() now to create a sink
 
-- we need to put out that new Windows build of nip2
-
 - im_jpeg2vips() etc, currently use vips_call() and therefore have an extra
   _write() ... this means that
 
@@ -43,6 +46,8 @@
   instead, they could be built on top of VipsFormat and use the compat layer
   there
 
+  check nip2: is it really only decompressing large images once?
+
 blocking bugs
 =============
 

libvips/include/vips/object.h

@@ -541,6 +541,10 @@ typedef void *(*VipsObjectSetArguments)( VipsObject *, void *, void * );
 VipsObject *vips_object_new( GType type, 
 	VipsObjectSetArguments set, void *a, void *b );
 
+int vips_object_set_valist( VipsObject *object, va_list ap );
+int vips_object_set( VipsObject *object, ... )
+	__attribute__((sentinel));
+
 VipsObject *vips_object_new_from_string( VipsObjectClass *object_class, 
 	const char *p );
 void vips_object_to_string( VipsObject *object, VipsBuf *buf );

libvips/include/vips/operation.h

@@ -88,8 +88,10 @@ void vips_operation_class_print_usage( VipsOperationClass *operation_class );
 
 int vips_operation_call_valist( VipsOperation *operation, va_list ap );
 VipsOperation *vips_operation_new( const char *name ); 
-int vips_call( const char *operation_name, ... );
-int vips_call_split( const char *operation_name, va_list optional, ... );
+int vips_call( const char *operation_name, ... )
+	__attribute__((sentinel));
+int vips_call_split( const char *operation_name, va_list optional, ... )
+	__attribute__((sentinel));
 
 void vips_call_options( GOptionGroup *group, VipsOperation *operation );
 int vips_call_argv( VipsOperation *operation, int argc, char **argv );

libvips/iofuncs/object.c

@@ -1770,6 +1770,54 @@ vips_object_new( GType type, VipsObjectSetArguments set, void *a, void *b )
 	return( object );
 }
 
+int
+vips_object_set_valist( VipsObject *object, va_list ap )
+{
+	char *name;
+
+	VIPS_DEBUG_MSG( "vips_object_set_valist:\n" );
+
+	name = va_arg( ap, char * );
+
+	while( name ) {
+		GParamSpec *pspec;
+		VipsArgumentClass *argument_class;
+		VipsArgumentInstance *argument_instance;
+
+		VIPS_DEBUG_MSG( "\tname = '%s' (%p)\n", name, name );
+
+		if( vips_object_get_argument( VIPS_OBJECT( object ), name,
+			&pspec, &argument_class, &argument_instance ) )
+			return( -1 );
+
+		VIPS_ARGUMENT_COLLECT_SET( pspec, argument_class, ap );
+
+		g_object_set_property( G_OBJECT( object ), 
+			name, &value );
+
+		VIPS_ARGUMENT_COLLECT_GET( pspec, argument_class, ap );
+
+		VIPS_ARGUMENT_COLLECT_END
+
+		name = va_arg( ap, char * );
+	}
+
+	return( 0 );
+}
+
+int
+vips_object_set( VipsObject *object, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( required, ap );
+	result = vips_object_set_valist( object, ap );
+	va_end( ap );
+
+	return( result );
+}
+
 /* Set object args from a string. @p should be the initial left bracket and
  * there should be no tokens after the matching right bracket.
  */

libvips/iofuncs/operation.c

@@ -347,41 +347,6 @@ vips_operation_set_valist_required( VipsOperation *operation, va_list ap )
 	return( 0 );
 }
 
-static int
-vips_operation_set_valist_optional( VipsOperation *operation, va_list ap )
-{
-	char *name;
-
-	VIPS_DEBUG_MSG( "vips_operation_set_valist_optional:\n" );
-
-	name = va_arg( ap, char * );
-
-	while( name ) {
-		GParamSpec *pspec;
-		VipsArgumentClass *argument_class;
-		VipsArgumentInstance *argument_instance;
-
-		VIPS_DEBUG_MSG( "\tname = '%s' (%p)\n", name, name );
-
-		if( vips_object_get_argument( VIPS_OBJECT( operation ), name,
-			&pspec, &argument_class, &argument_instance ) )
-			return( -1 );
-
-		VIPS_ARGUMENT_COLLECT_SET( pspec, argument_class, ap );
-
-		g_object_set_property( G_OBJECT( operation ), 
-			name, &value );
-
-		VIPS_ARGUMENT_COLLECT_GET( pspec, argument_class, ap );
-
-		VIPS_ARGUMENT_COLLECT_END
-
-		name = va_arg( ap, char * );
-	}
-
-	return( 0 );
-}
-
 static int
 vips_operation_get_valist_required( VipsOperation *operation, va_list ap )
 {
@@ -506,7 +471,7 @@ vips_call_required_optional( VipsOperation **operation,
 	va_copy( a, required );
 	va_copy( b, optional );
 	result = vips_operation_set_valist_required( *operation, a ) ||
-		vips_operation_set_valist_optional( *operation, b );
+		vips_object_set_valist( *operation, b );
 	va_end( a );
 	va_end( b );