Equality predicate optional, start testing.

src/util-set-list.scm

@@ -31,22 +31,28 @@
   TAG-LSET
 
   make-lset
-  lset-add
-  lset-remove
+
+  lset-empty?
 
   lset-member?
   
+  lset-add
+  lset-remove
+
   list->lset
   lset->list
 
   lset-merge
   lset-intersect
   lset-subtract
+
+  lset-tests!
   )
 
  (import scheme
 	 (chicken string)
-	 (chicken random))
+	 (chicken random)
+	 testing)
 
  ;; Tag used for identifying list sets from this module
  (define TAG-LSET
@@ -64,15 +70,22 @@
     ""))
 
  ;; Creates new list set using given equality procedure
- (define (make-lset equality?)
-   (list TAG-LSET
-	 (list equality?)))
+ (define (make-lset . equality?)
+   (let ((equality? (if (null? equality?)
+			equal?
+			(car equality?))))
+     (list TAG-LSET
+	   (list equality?))))
 
  ;; Convenience accessors
  (define lset-meta cadr)
  (define lset-equality? caadr)
  (define lset-list cddr)
 
+ ;; Returns true if the list set is empty
+ (define (lset-empty? ls)
+   (null? (lset-list ls)))
+
  ;; Returns true if given element is in the list
  (define (lset-member? ls el)
    (let ((equality? (lset-equality? ls)))
@@ -155,20 +168,14 @@
 	 (loop (cdr lst)
 	       (lset-remove ls (car lst))))))
 
+ ;; Module self-tests
+ (define (lset-tests!)
+   (run-tests
+    lset
+    (test-true make-lset/lset-empty? (lset-empty? (make-lset)))
+    ))
+
  )
 
 (import util-set-list)
-
-(print TAG-LSET)
-(print (make-lset string=?))
-(define ls (make-lset string=?))
-(print ls)
-(define ls1 (lset-add ls "a"))
-(print ls1)
-(define ls2 (lset-add ls1 "a"))
-(print ls2)
-(define ls3 (lset-add ls2 "b"))
-(print ls3)
-(define ls4 (lset-remove ls3 "a"))
-(print ls4)
-(print (list->lset '("asdf" "qwer" "asdf" "xcvv" "asdf" "qwer" "lkjh") string=?))
+(lset-tests!)