GST FFI binding

gst.rkt

#lang racket/base

(require ffi/unsafe
         ffi/unsafe/define
         racket/stxparam
         racket/splicing
         (for-syntax racket/base
                     syntax/parse
                     racket/syntax
                     racket/string))

(provide (all-defined-out))

(define gstreamer-lib (ffi-lib "libgstreamer-1.0" '("0")))
(define-ffi-definer define-gst gstreamer-lib)
(define-syntax-parameter current-func-name #f)
(define-syntax (define-gst* stx)
  (syntax-parse stx
    [(_ name:id args ...)
     #:with c-name (format-id stx "~a" (string-replace (symbol->string (syntax-e #'name)) "-" "_"))
     (syntax/loc stx
       (splicing-syntax-parameterize ([current-func-name (make-rename-transformer #'name)])
         (define-gst name args ...
           #:c-id c-name)))]))

;; Types
(define _gquark _uint32)
(define-cstruct _gerror
  ([domain _gquark]
   [code _int]
   [message _string]))

(define-gst* gst-init (_fun [_int = (length vec)] [vec : (_list i _string)] -> _void))
(define-gst* gst-init-check (_fun [_int = (length vec)] [vec : (_list i _string)] _gerror-pointer
                                  -> [v : _bool]
                                  ));-> (ret-error v)))