Clean up validation of play arguments

modules/ordo/play.scm

@@ -19,12 +19,19 @@
   (tasks play-tasks)
   (handlers play-handlers))
 
-(define* (play description #:key connection tasks (vars '()) (handlers '()))
-  (unless connection (error "connection is required"))
-  (unless (is-a? connection <connection>) (error (format #f "invalid connection: ~a" connection)))
-  (unless (and tasks (not (null? tasks))) (error "tasks are required"))
-  (unless (every task? tasks) (error "invalid tasks"))
-  (unless (every (compose handler? cdr) handlers) (error "invalid handlers"))
+(define (validate-connection connection)
+  (unless (and connection (is-a? connection <connection>))
+    (error (format #f "invalid connection: ~a" connection))))
+
+(define (validate-tasks tasks)
+  (unless (and tasks (not (null? tasks)) (every task? tasks))
+    (error (format #f "invalid tasks: ~a" tasks))))
+
+(define (validate-handlers handlers)
+  (unless (every (lambda (h) (and (pair? h) (handler? (cdr h)))) handlers)
+    (error (format #f "invalid handlers: ~a" handlers))))
+
+(define (validate-triggers tasks handlers)
   (for-each (lambda (task)
               (for-each (lambda (trigger)
                           (unless (assoc-ref handlers trigger)
@@ -32,7 +39,13 @@
                                            (task-description task)
                                            trigger))))
                         (task-triggers task)))
-            tasks)
+            tasks))
+
+(define* (play description #:key connection tasks (vars '()) (handlers '()))
+  (validate-connection connection)
+  (validate-tasks tasks)
+  (validate-handlers handlers)
+  (validate-triggers tasks handlers)
   (make-play description connection (fold (match-lambda* (((k . v) accum) (alist-cons k v accum))) '() vars) tasks handlers))
 
 (define (run-play play)