minor improvements

day05-hard/main.scm

@@ -378,10 +378,12 @@
 (define symbol-current (quote current))
 (define symbol-previous (quote previous))
 
-(define (mark-state-value-previous state-entry) (cons symbol-previous (cdr state-entry)))
 (define (is-state-value-current state-entry) (equal? symbol-current (car state-entry)))
 (define get-state-value cdr)
-(define create-state-value cons)
+(define (create-state-value state-symbol) (lambda (range) (cons state-symbol range)))
+(define create-state-value-current (create-state-value symbol-current))
+(define create-state-value-previous (create-state-value symbol-previous))
+(define (mark-state-value-previous state-entry) (create-state-value-previous (cdr state-entry)))
 (define swap-state (compose (list
   #!(tee-with-comment "state after swap")!#
   (map mark-state-value-previous)
@@ -395,17 +397,6 @@
 (define get-range-start car)
 (define get-range-end (compose (list car cdr)))
 
-(define parse-initial
-  (compose (list
-    (map (lambda (raw-range) (create-state-value symbol-current (create-range-from-input raw-range))))
-    (chunks 2)
-    (map (compose (list
-      string->number
-      list->string)))
-    cdr
-    (split (is #\space))
-    string->list)))
-
 (define (create-map numbers) (list
   ;; convert it from destination_start, source_start, length
   ;; to source_start, source_end, destination_start
@@ -422,11 +413,11 @@
     (map (lambda (intersection)
       (if
         (equal? symbol-in-both-ranges (car intersection))
-        (create-state-value symbol-current
+        (create-state-value-current
           (create-range
             (+ map-destination-start (- (get-range-start (cdr intersection)) map-source-start))
             (+ map-destination-start (- (get-range-end (cdr intersection)) map-source-start))))
-        (create-state-value symbol-previous (create-range (get-range-start (cdr intersection)) (get-range-end (cdr intersection)))))))
+        (create-state-value-previous (create-range (get-range-start (cdr intersection)) (get-range-end (cdr intersection)))))))
     (filter (lambda (intersection)
       (or
         (equal? symbol-in-second-range (car intersection))
@@ -478,6 +469,19 @@
       raw-seed-maps)
     swap-state)))
 
+(define parse-initial
+  (compose (list
+    (map (compose (list
+      create-state-value-current
+      create-range-from-input)))
+    (chunks 2)
+    (map (compose (list
+      string->number
+      list->string)))
+    cdr
+    (split (is #\space))
+    string->list)))
+
 (define (final-state lines)
   (((compose (list
     compose