updates

coerce/contract.rkt

@@ -1,7 +1,9 @@
 #lang racket/base
+(require (for-syntax racket/base racket/syntax))
 (require racket/contract "../define/provide.rkt" "value.rkt")
 
 
+
 (define-syntax-rule (make-blame-handler try-proc expected-sym)
   (λ(b)
     (λ(x)
@@ -12,35 +14,28 @@
                                     expected-sym x))])
         (try-proc x)))))
 
-(define+provide coerce/integer?
-  (make-contract
-   #:name 'coerce/integer?
-   #:projection (make-blame-handler ->int 'can-be-integer?)))
-
 
-(define+provide coerce/string?
+(provide make-coercion-contract)
+(define-syntax (make-coercion-contract stx)
+  (syntax-case stx ()
+    [(_ stem)
+     (let ([stem-datum (syntax->datum #'stem)])
+       (with-syntax ([coerce/stem? (format-id stx "coerce/~a?" #'stem)]
+                     [->stem (format-id stx "->~a" #'stem)]
+                     [can-be-stem? (format-id stx "can-be-~a?" #'stem)])
+         #'(define+provide coerce/stem?
              (make-contract
-   #:name 'coerce/string?
-   #:projection (make-blame-handler ->string 'can-be-string?)))
-
-
-(define+provide coerce/symbol?
-  (make-contract
-   #:name 'coerce/symbol?
-   #:projection (make-blame-handler ->symbol 'can-be-symbol?)))
-
-
-(define+provide coerce/path?
-  (make-contract
-   #:name 'coerce/path?
-   #:projection (make-blame-handler ->path 'can-be-path?)))
-
-
-(define+provide coerce/boolean?
-  (make-contract
-   #:name 'coerce/boolean?
-   #:projection (make-blame-handler ->boolean 'can-be-boolean?)))
-
+              #:name 'coerce/stem?
+              #:projection (make-blame-handler ->stem 'can-be-stem?)))))]))
 
 
+(make-coercion-contract int)
+(make-coercion-contract string)
+(make-coercion-contract symbol)
+(make-coercion-contract path)
+(make-coercion-contract boolean)
 
+#|
+(define/contract (foo x)
+  (coerce/string? . -> . any/c)
+  x)|#

list.rkt

@@ -52,6 +52,6 @@
       (let* ([duplicate-keys (filter-not empty? (hash-map (count-incidence x) 
                                                           (λ(k v) (if (> v 1) k '()))))])
         (error (string-append (if (= (len duplicate-keys) 1) 
-                                  "Item isn’t"
-                                  "Items aren’t") " unique:") duplicate-keys))
+                                  "item isn’t"
+                                  "items aren’t") " unique:") duplicate-keys))
       result))