Type sbf.

functions.rkt

@@ -31,7 +31,7 @@
 
    (struct-out tbf) tbf-w tbf-θ boolean->01/vector apply-tbf apply-tbf/boolean
    list->tbf lists->tbfs read-org-tbfs tbf-tabulate* tbf-tabulate
-   tbf-tabulate*/boolean sbf?)
+   tbf-tabulate*/boolean sbf? sbf)
 
   (module+ test
     (require typed/rackunit))
@@ -548,6 +548,14 @@
       (check-false (sbf? (tbf #(1 2) 3)))
       (check-true (sbf? (tbf #(1 2) 0)))))
 
+  (: sbf (-> (Vectorof Real) tbf))
+  (define (sbf w)
+    (tbf w 0))
+
+  (module+ test
+    (test-case "sbf"
+      (check-equal? (sbf #(1 -1)) (tbf '#(1 -1) 0))))
+
   (module untyped racket
     (module+ test
       (require rackunit))
@@ -638,7 +646,7 @@
 
  (struct-out tbf) tbf-w tbf-θ boolean->01/vector apply-tbf apply-tbf/boolean
  list->tbf lists->tbfs read-org-tbfs tbf-tabulate* tbf-tabulate
- tbf-tabulate*/boolean sbf?)
+ tbf-tabulate*/boolean sbf? sbf)
 
 (require (rename-in (submod 'typed untyped)
                     [tabulate tabulate/untyped]
@@ -647,7 +655,6 @@
 (provide
  ;; Functions
  (contract-out
-  [sbf (-> (vectorof number?) tbf?)]
   [list->sbf (-> (listof number?) sbf?)]
   [read-org-sbfs (->* (string?) (#:headers boolean?) (listof sbf?))]))
 
@@ -659,13 +666,6 @@
 ;;; Threshold Boolean functions
 ;;; ===========================
 
-;;; Creates a TBF which is an SBF from a vector of weights.
-(define (sbf w) (tbf w 0))
-
-(module+ test
-  (test-case "sbf"
-    (check-equal? (sbf #(1 -1)) (tbf '#(1 -1) 0))))
-
 ;;; Converts a list of numbers to an SBF.  The elements of the list
 ;;; are taken to be the weights of the SBF.
 (define list->sbf (compose sbf list->vector))

scribblings/functions.scrbl

@@ -574,6 +574,14 @@ A sign Boolean function (SBF) is a TBF whose threshold is 0.
 (sbf? (tbf #(1 2) 0))
 ]}
 
+@defproc[(sbf [w (Vectorof Real)]) tbf]{
+
+Creates a TBF which is an SBF from a vector of weights.
+
+@ex[
+(sbf #(1 -1))
+]}
+
 @section[#:tag "fuctions/untyped"]{Untyped definitions}
 
 @defmodule[(submod dds/functions typed untyped)]