Audio error handling added - first basics, need to be enhanced

audio-decoder.rkt

@@ -6,6 +6,7 @@
            "ffmpeg-decoder.rkt"
            "audio-sniffer.rkt"
            "private/utils.rkt"
+           "audio-errors.rkt"
            racket/contract
            racket/string
            racket/path
@@ -193,13 +194,20 @@
     (let ((file (if (path? audio-file)
                     (path->string audio-file)
                     audio-file)))
-      (unless (audio-file-valid? audio-file)
-        (error (format "Not a valid audio file '~a'" audio-file)))
+
       (unless (file-exists? audio-file)
-        (error (format "File '~a' does not exist" audio-file)))
+        (raise-audio-error 'file-not-found
+                           "File not found: '~a'" audio-file))
+
+      (unless (audio-file-valid? audio-file)
+        (raise-audio-error 'invalid-audio-file
+                           "Not a valid audio file: '~a'" audio-file))
+      
       (let ((reader* (find-reader audio-file)))
         (when (eq? reader* #f)
-          (error (format "Cannot find reader for '~a'" audio-file)))
+          (raise-audio-error 'no-audio-reader
+                             "Cannot find reader for '~a'" audio-file))
+
         (let* ((reader-type (car reader*))
                (reader (cadr reader*))
                (ao-type (audio-reader-ao-type reader))

audio-errors.rkt

@@ -0,0 +1,66 @@
+#lang racket/base
+
+(require (for-syntax racket/base)
+         racket/path)
+
+
+(provide exn:fail:audio
+         exn:fail:audio?
+         exn:fail:audio-code
+         raise-audio-error
+         make-audio-error-code
+         exn-audio-code
+         )
+
+(struct exn:fail:audio exn:fail
+  (code source line)
+  #:transparent)
+
+(define exn-audio-code exn:fail:audio-code)
+
+(define (audio-codes)
+  '(no-decoder no-encoder
+    file-not-found
+    invalid-audio-file
+    no-audio-reader
+    audio-file-corrupt
+    audio-error))
+
+(define (make-audio-code code)
+  (if (symbol? code)
+      (letrec ((f (λ (l)
+                    (if (null? (cdr l))
+                        (car l)
+                        (if (eq? (car l) code)
+                            code
+                            (f (cdr l)))))))
+        (f (audio-codes)))
+      (make-audio-code (string->symbol (format "~a" code)))))
+
+(define (make-audio-error-code c)
+  (make-audio-code c))
+
+
+(define (raise-audio-error* code source line message . args)
+  (let* ((msg (apply format (cons message args)))
+         (src* (file-name-from-path (build-path source)))
+         (msg* (format "~a at ~a, line ~a" msg src* line)))
+      (raise (exn:fail:audio msg*
+                             (current-continuation-marks)
+                             (make-audio-code code)
+                             source
+                             line))))
+
+(define-syntax (raise-audio-error stx)
+  (syntax-case stx ()
+    ((_ code message ...)
+     (let ((src (syntax-source stx))
+           (line (syntax-line stx)))
+       #`(raise-audio-error* code '#,src '#,line message ...)))))
+
+(define (test x)
+  (if (> x 10)
+      (raise-audio-error 'file-notd-found "File not found: ~a" "c:/muziek/a.flac")
+      #t))
+
+