refactoring

parking.scm

@@ -9,9 +9,18 @@
   (lambda (b)
     (fn a b)))
 
+(define (curry2 fn a b)
+  (lambda (c)
+    (fn a b c)))
+
 (define (perhaps fn a)
   (if a (fn a) a))
 
+(define (upon pred? fn a)
+  (if (pred? a)
+      (fn a)
+      a))
+
 (define (member? a ln)
   (if (member a ln) #t #f))
 
@@ -43,10 +52,7 @@
     
 (define (format-assoc statement ln)
   (apply string-append
-         (map (lambda (directive)
-                (if (symbol? directive)
-                    (->string (value directive ln))
-                    directive)) statement)))
+         (map (curry2 upon symbol? (compose ->string (curry (flip value) ln))) statement)))
 
 (define (simple-json-request uri)
   (with-input-from-request uri #f read-json))