Type list->tbf.

functions.rkt

@@ -27,7 +27,8 @@
    enumerate-boolean-functions/pv enumerate-boolean-functions/list
    random-boolean-table random-boolean-function random-boolean-function/list
 
-   (struct-out tbf) tbf-w tbf-θ boolean->01/vector apply-tbf apply-tbf/boolean)
+   (struct-out tbf) tbf-w tbf-θ boolean->01/vector apply-tbf apply-tbf/boolean
+   list->tbf)
 
   (module+ test
     (require typed/rackunit))
@@ -394,6 +395,15 @@
       (check-equal? (tabulate/pv/boolean 2 (pvλ (x y) (apply-tbf/boolean f1 (vector x y))))
                     '((#f #f #f) (#f #t #f) (#t #f #t) (#t #t #f)))))
 
+  (: list->tbf (-> (Listof Real) tbf))
+  (define (list->tbf lst)
+    (define-values (w θ) (split-at-right lst 1))
+    (tbf (list->vector w) (car θ)))
+
+  (module+ test
+    (test-case "list->tbf"
+      (check-equal? (list->tbf '(1 2 3)) (tbf #(1 2) 3))))
+
   (module untyped racket
     (module+ test
       (require rackunit))
@@ -480,7 +490,8 @@
  enumerate-boolean-functions/pv enumerate-boolean-functions/list
  random-boolean-table random-boolean-function random-boolean-function/list
 
- (struct-out tbf) tbf-w tbf-θ boolean->01/vector apply-tbf apply-tbf/boolean)
+ (struct-out tbf) tbf-w tbf-θ boolean->01/vector apply-tbf apply-tbf/boolean
+ list->tbf)
 
 (require (rename-in (submod 'typed untyped)
                     [tabulate tabulate/untyped]
@@ -489,7 +500,6 @@
 (provide
  ;; Functions
  (contract-out
-  [list->tbf (-> (cons/c number? (cons/c number? (listof number?))) tbf?)]
   [lists->tbfs (-> (listof (listof number?)) (listof tbf?))]
   [read-org-tbfs (->* (string?) (#:headers boolean?) (listof tbf?))]
   [tbf-tabulate* (-> (listof tbf?) (listof (listof (or/c 0 1))))]
@@ -510,17 +520,6 @@
 ;;; Threshold Boolean functions
 ;;; ===========================
 
-;;; Converts a list of numbers to a TBF.  The last element of the list
-;;; is taken to be the threshold, while the other elements are taken
-;;; to be the weights.
-(define (list->tbf lst)
-  (define-values (w θ) (split-at-right lst 1))
-  (tbf (list->vector w) (car θ)))
-
-(module+ test
-  (test-case "list->tbf"
-    (check-equal? (list->tbf '(1 2 3)) (tbf #(1 2) 3))))
-
 ;;; Reads a list of TBF from an Org-mode table read by
 ;;; read-org-sexp.
 (define lists->tbfs ((curry map) list->tbf))

scribblings/functions.scrbl

@@ -415,6 +415,15 @@ a Boolean value.
 (tabulate/pv/boolean 2 (pvλ (x y) (apply-tbf/boolean simple-tbf (vector x y))))
 ]}
 
+@defproc[(list->tbf [lst (Listof Real)]) tbf]{
+
+Converts a list of numbers to a TBF.  The last element of the list is taken to
+be the threshold, while the other elements are taken to be the weights.
+
+@examples[#:eval functions-evaluator
+(list->tbf '(1 2 3))
+]}
+
 @section[#:tag "fuctions/untyped"]{Untyped definitions}
 
 @defmodule[(submod dds/functions typed untyped)]