Fix foldable interfaces

1 files changed, 27 insertions, 27 deletions

diff --git a/algebraic-structures.foldable.scm b/algebraic-structures.foldable.scm
index 3ab1f6e..be3d615 100644
--- a/algebraic-structures.foldable.scm
+++ b/algebraic-structures.foldable.scm
@@ -1,39 +1,39 @@
-(functor ((algebraic-structures foldable) (F (foldl foldr)))
-    (foldl foldr length find any every ->list)
-  (import (except scheme length) F
+(functor ((algebraic-structures foldable) (F (fold)))
+    (fold
+     length
+     count
+     any
+     every)
+  (import (except scheme length)
+          F
           (only (chicken base) add1 call/cc))
 
   (define (length xs)
-    (foldl (lambda (acc _) (add1 acc))
-           0
-           xs))
+    (fold (lambda (_ acc) (add1 acc))
+          0
+          xs))
 
-  (define (find p? xs)
-    (call/cc
-     (lambda (k)
-       (foldl (lambda (acc e)
-                (if (p? e)
-                    (k e)
-                    acc))
-              #f
-              xs))))
+  (define (count p? xs)
+    (fold (lambda (e acc)
+            (if (p? e)
+                (add1 acc)
+                acc))
+          0
+          xs))
 
   (define (any pred xs)
     (call/cc
      (lambda (return)
-       (foldl (lambda (acc e)
-                (cond ((pred e) => return)
-                      (else acc)))
-              #f
-              xs))))
+       (fold (lambda (e acc)
+               (cond ((pred e) => return)
+                     (else acc)))
+             #f
+             xs))))
 
   (define (every pred xs)
     (call/cc
      (lambda (return)
-       (foldl (lambda (acc e)
-                (or (pred e) (return #f)))
-              #t
-              xs))))
-
-  (define (->list xs)
-    (foldr cons '() xs)))
+       (fold (lambda (e acc)
+               (or (pred e) (return #f)))
+             #t
+             xs)))))