! In the code below, I want wand, fill and bordercolor to be passed in ! as tuple types, which each have a c-wand>> method defined on them, ! which turns them into alien types. ! ! MagickFloodfillPaintImage-safe expects alien types like that. It ! looks so horrible because it's generated by a parsing word from the ! (slightly) nicer thing below. ! ! So my question came about because, while most of ImageMagick's ! functions expect just one pointer to an object as the first argument ! and then stuff that gets converted automatically, some have more ! complicated arguments. The ::-based approach below has to be done by ! hand, which is boring and messy, so I was wondering whether there ! was a neater way. ! ! Incidentally, if what I was asking was a bit unclear on IRC, what I ! was hoping for is called a "foreign type translator" ! (http://tinyurl.com/6ud45e) in Lisp's CFFI. I assumed (wrongly) that ! that sort of functionality was what was being used to make the char* ! conversion magic work. ! ! Anyway, essay over. I wondered if you had any suggestions for how I ! could abstract out the sort of transformations one needs. ! This one hand-written :: floodfill-paint ( wand channel fill fuzz bordercolor x y invert -- wand ) wand dup c-wand>> channel fill c-wand>> fuzz bordercolor c-wand>> x y invert MagickFloodfillPaintImage-safe ; ! This generated by a parser word. USING: generalizations kernel magickwand.libmagickwand.syntax ; IN: magickwand.libmagickwand : MagickFloodfillPaintImage-safe ( wand channel, fill, fuzz, bordercolor, x, y, invert -- ) 8 npick [ MagickFloodfillPaintImage ] [ call 0 = ] curry dip swap [ throw-magick-error ] [ drop ] if ; ! This hand (and regexp!) written. BOOL-WAND-FUN: FloodfillPaintImage ( int channel, void* fill, double fuzz, void* bordercolor, long x, long y, int invert ) ;