Add `cons-of' signature constructor to HtDP languages.

collects/lang/htdp-advanced.rkt

@@ -63,6 +63,7 @@
 
 	   signature : -> mixed one-of predicate combined
 	   Number Real Rational Integer Natural Boolean True False String Symbol Char Empty-list Any
+	   cons-of
 	   Property
 	   check-property for-all ==> expect expect-within expect-member-of expect-range)
 

collects/lang/htdp-beginner-abbr.rkt

@@ -45,6 +45,7 @@
 
 	   signature : -> mixed one-of predicate combined
 	   Number Real Rational Integer Natural Boolean True False String Symbol Char Empty-list Any
+	   cons-of
 	   Property
 	   check-property for-all ==> expect expect-within expect-member-of expect-range)
 

collects/lang/htdp-beginner.rkt

@@ -46,6 +46,7 @@
 
 	   signature : -> mixed one-of predicate combined
 	   Number Real Rational Integer Natural Boolean True False String Symbol Char Empty-list Any
+	   cons-of
 	   Property
 	   check-property for-all ==> expect expect-within expect-member-of expect-range)
 

collects/lang/htdp-intermediate-lambda.rkt

@@ -49,6 +49,7 @@
 
 	   signature : -> mixed one-of predicate combined
 	   Number Real Rational Integer Natural Boolean True False String Symbol Char Empty-list Any
+	   cons-of
 	   Property
 	   check-property for-all ==> expect expect-within expect-member-of expect-range)
 

collects/lang/htdp-intermediate.rkt

@@ -49,6 +49,7 @@
 
 	   signature : -> mixed one-of predicate combined
 	   Number Real Rational Integer Natural Boolean True False String Symbol Char Empty-list Any
+	   cons-of
 	   Property 
 	   check-property for-all ==> expect expect-within expect-member-of expect-range)
 

collects/lang/private/beginner-funs.rkt

@@ -223,14 +223,14 @@
       (null empty
 	"the empty list")
 
-      (first ( (cons Y (listof X)) -> Y )
+      ((beginner-first first) ( (cons Y (listof X)) -> Y )
 	"to select the first item of a non-empty list")
-      (car ( (cons Y (listof X)) -> Y )
+      ((beginner-car car) ( (cons Y (listof X)) -> Y )
 	"to select the first item of a non-empty list")       
-      (rest ((cons Y (listof X)) -> (listof X))
+      ((beginner-rest rest) ((cons Y (listof X)) -> (listof X))
+	"to select the rest of a non-empty list")
+      ((beginner-cdr cdr) ((cons Y (listof X)) -> (listof X))
 	"to select the rest of a non-empty list")
-      (cdr ((cons Y (listof X)) -> (listof X))
-	"to select the rest of a non-empty list")       
     
       (second ( (cons Z (cons Y (listof X))) -> Y )
 	"to select the second item of a non-empty list")

collects/lang/private/teach.rkt

@@ -2882,7 +2882,8 @@
 (provide Integer Number Rational Real Natural 
 	 Boolean True False
 	 String Char Symbol Empty-list
-	 Any Unspecific)
+	 Any Unspecific
+	 cons-of)
 
 (define Integer (signature/arbitrary arbitrary-integer (predicate integer?)))
 (define Number (signature/arbitrary arbitrary-real (predicate number?)))
@@ -2909,6 +2910,9 @@
 
 (define Unspecific (signature (predicate (lambda (_) #t))))
 
+(define (cons-of car-sig cdr-sig)
+  (make-pair-signature car-sig cdr-sig))
+
 ; QuickCheck
 
 (provide for-all ==>

collects/lang/private/teachprims.rkt

@@ -16,7 +16,8 @@ namespace.
 
 (require mzlib/list 
          mzlib/math
-         mzlib/etc)
+         mzlib/etc
+	 deinprogramm/signature/signature)
 
 (define-syntax (define-teach stx)
   (syntax-case stx ()
@@ -178,6 +179,18 @@ namespace.
     (check-second 'cons a b)
     (cons a b)))
 
+(define-teach beginner car
+  (lambda (p) (checked-car p)))
+
+(define-teach beginner first
+  (lambda (p) (checked-car p)))
+
+(define-teach beginner cdr
+  (lambda (p) (checked-cdr p)))
+
+(define-teach beginner rest
+  (lambda (p) (checked-cdr p)))
+
 (define-teach beginner list*
   (lambda x
     (check-last 'list* x)
@@ -382,6 +395,10 @@ namespace.
  beginner-member?
  beginner-remove
  beginner-cons
+ beginner-car
+ beginner-cdr
+ beginner-first
+ beginner-rest
  beginner-list*
  beginner-append
  intermediate-append