Type list-enabled.

rs.rkt

@@ -5,7 +5,7 @@
 
   (provide
    Species (struct-out reaction) Reaction ReactionSystem
-   make-reaction enabled?)
+   make-reaction enabled? list-enabled)
 
   (module+ test
     (require typed/rackunit))
@@ -42,6 +42,19 @@
                              (set 'b 'e)))))
 
   (define-type ReactionSystem (HashTable Symbol Reaction))
+
+  (: list-enabled (-> ReactionSystem (Setof Species) (Listof Symbol)))
+  (define (list-enabled rs s)
+    (for/list ([(name reaction) (in-hash rs)]
+               #:when (enabled? reaction s))
+      name))
+
+  (module+ test
+    (test-case "list-enabled"
+      (define rs (hash 'a (make-reaction '(x) '(y) '(z))
+                       'b (make-reaction '(x y) '() '(z))))
+      (check-equal? (list-enabled rs (set 'x 'y)) '(b))
+      (check-equal? (list-enabled rs (set 'x)) '(a))))
   )
 
 (require graph "utils.rkt" "generic.rkt")

scribblings/rs.scrbl

@@ -80,6 +80,19 @@ A reaction system is a dictionary mapping reaction names
 
 }
 
+@defproc[(list-enabled [rs ReactionSystem] [s (Setof Species)]) (Listof Symbol)]{
+
+Returns the list of the names of reactions of @racket[rs] enabled on
+@racket[s].
+
+@ex[
+(let ([rs (hash 'a (make-reaction '(x) '(y) '(z))
+                'b (make-reaction '(x y) '() '(z)))])
+  (values (list-enabled rs (set 'x 'y))
+          (list-enabled rs (set 'x))))
+]}
+
+
 
 @section{Org-mode interaction}