utils: Move drop-first-last from rs and add list-sets->list-strings.

rs.rkt

@@ -110,10 +110,6 @@
 ;;; A shortcut to read-context-sequence.
 (define-syntax-rule (read-ctx str) (read-context-sequence str))
 
-;;; Removes the first and the last symbol of a given string.
-(define (drop-first-last str)
-  (substring str 1 (- (string-length str) 1)))
-
 ;;; Converts a reaction to a triple of strings.
 (define/match (reaction->str-triple r)
   [((reaction r i p))

utils-tests.rkt

@@ -61,7 +61,10 @@
     (check-equal? (hash-ref m1 'b) '(or b (not a)))
     (check-equal? (hash-ref m2 'b) '(or b (not a)))
     (check-equal? (hash-ref m3 'b) '(or b (not a))))
-  (check-equal? (read-symbol-list "a b c") '(a b c)))
+  (check-equal? (read-symbol-list "a b c") '(a b c))
+  (check-equal? (drop-first-last "(a b)") "a b")
+  (check-equal? (list-sets->list-strings (list (set 'x 'y) (set 'z) (set) (set 't)))
+                '("y x" "z" "" "t")))
 
 (test-case "Additional graph utilities"
   (let* ([gr1 (directed-graph '((a b) (b c)))]

utils.rkt

@@ -20,6 +20,8 @@
                                       (listof (general-pair/c symbol? any/c)))]
                [read-org-variable-mapping (-> string? variable-mapping?)]
                [read-symbol-list (-> string? (listof symbol?))]
+               [drop-first-last (-> string? string?)]
+               [list-sets->list-strings (-> (listof (set/c any/c)) (listof string?))]
                [update-vertices/unweighted (-> graph? (-> any/c any/c) graph?)]
                [update-graph (->* (graph?)
                                   (#:v-func (-> any/c any/c)
@@ -224,6 +226,18 @@
 (define (read-symbol-list str)
   (string->any (string-append "(" str ")")))
 
+;;; Removes the first and the last symbol of a given string.
+;;;
+;;; Useful for removing the parentheses in string representations of
+;;; lists.
+(define (drop-first-last str)
+  (substring str 1 (- (string-length str) 1)))
+
+;;; Converts a list of sets of symbols to a list of strings containing
+;;; those symbols.
+(define (list-sets->list-strings lst)
+  (map (compose drop-first-last any->string set->list) lst))
+
 
 ;;; ==========================
 ;;; Additional graph utilities