Compile new lset.

src/util-bst-lset.scm

@@ -0,0 +1,65 @@
+
+(declare (unit util-bst-lset))
+
+(import duck)
+
+(module*
+ util-bst-lset
+ #:doc ("Reimplementation of old lset using new BST backend.")
+ (
+  make-lset
+  lset?
+  lset-empty?
+  lset-member?
+  lset-count
+  lset-add
+  lset-remove
+  list->lset
+  lset->list
+  lset-merge
+  lset-intersect
+  lset-subtract
+  lset=?
+  )
+ (import scheme
+	 util-bst
+	 racket-kwargs
+	 util-bst-ldict
+	 util-list)
+
+ (define* (make-lset (equality? equal?))
+   (make-bst 'lset equality? ldict<?))
+
+ (define lset? (bst? 'lset))
+
+ (define lset-empty? bst-empty?)
+ (define lset-member? bst-contains?)
+ (define lset-count bst-count)
+
+ (define (lset-add ls e)
+   (bst-set ls e #t))
+
+ (define lset-remove bst-remove)
+
+ (define* (list->lset lst (equality? equal?))
+   (foldl lset-add (make-lset equality?) lst))
+ 
+ (define lset->list bst-keys)
+
+ (define (lset=? ls1 ls2)
+   (bst-equal? ls1 ls2))
+
+ (define (lset-merge ls1 ls2)
+   (foldl lset-add ls1 (lset->list ls2)))
+
+ (define (lset-intersect ls1 ls2)
+   (list->lset
+    (filter (lambda (el)
+	      (lset-member? ls2 el))
+	    (lset->list ls1))
+    (bst-EQ? ls1)))
+
+ (define (lset-subtract ls1 ls2)
+   (foldl lset-remove ls1 (lset->list ls2)))
+
+ )