correct contract on indenter

beautiful-racket-demo/jsonic-demo-2/indenter.rkt

@@ -8,8 +8,7 @@
 (define (indent-jsonic tbox [posn 0])
   (define prev-line (previous-line tbox posn))
   (define current-line (line tbox posn))
-  (define prev-indent (or (line-indent tbox prev-line) 0))
-  (define current-indent
+  (define prev-indent (line-indent tbox prev-line))
   (cond
     [(left-bracket?
       (line-first-visible-char tbox prev-line))
@@ -18,13 +17,11 @@
       (line-first-visible-char tbox current-line))
      (- prev-indent indent-width)]
     [else prev-indent]))
-  (and (exact-positive-integer? current-indent)
-       current-indent))
 (provide
  (contract-out
   [indent-jsonic (((is-a?/c text%)) 
                   (exact-nonnegative-integer?) . ->* .
-                  (or/c exact-positive-integer? #f))]))
+                  exact-nonnegative-integer?)]))
 
 (module+ test
   (require rackunit)
@@ -45,4 +42,4 @@ HERE
     )
   (check-equal?
    (string-indents (apply-indenter indent-jsonic test-str))
-   '(#f #f 2 2 2 4 6 6 4 2 2 #f)))
+   '(0 0 2 2 2 4 6 6 4 2 2 0)))

beautiful-racket-demo/jsonic-demo-3/indenter.rkt

@@ -8,8 +8,7 @@
 (define (indent-jsonic tbox [posn 0])
   (define prev-line (previous-line tbox posn))
   (define current-line (line tbox posn))
-  (define prev-indent (or (line-indent tbox prev-line) 0))
-  (define current-indent
+  (define prev-indent (line-indent tbox prev-line))
   (cond
     [(left-bracket?
       (line-first-visible-char tbox prev-line))
@@ -18,12 +17,11 @@
       (line-first-visible-char tbox current-line))
      (- prev-indent indent-width)]
     [else prev-indent]))
-  (and (exact-positive-integer? current-indent) current-indent))
 (provide
  (contract-out
   [indent-jsonic (((is-a?/c text%)) 
                   (exact-nonnegative-integer?) . ->* .
-                  (or/c exact-nonnegative-integer? #f))]))
+                  exact-nonnegative-integer?)]))
 
 (module+ test
   (require rackunit)
@@ -44,5 +42,4 @@ HERE
     )
   (check-equal?
    (string-indents (apply-indenter indent-jsonic test-str))
-   '(#f #f 2 2 2 4 6 6 4 2 2 #f)))
-  
+   '(0 0 2 2 2 4 6 6 4 2 2 0)))

beautiful-racket-lib/br/indent.rkt

@@ -149,11 +149,10 @@
   (and (valid-line? text line)
        (let ([lsv (line-start-visible text line)])
          (and lsv ; could be #f
-              (let ([li (- (line-start-visible text line) (line-start text line))])
-                (and (positive? li) li))))))
+              (- (line-start-visible text line) (line-start text line))))))
 
 (module+ test
-  (check-equal? (line-indent t 0) #f)
+  (check-equal? (line-indent t 0) 0)
   (check-equal? (line-indent t 1) 1)
   (check-equal? (line-indent t 2) 2)
   (check-equal? (line-indent t 3) #f))
@@ -198,10 +197,9 @@
   (send indented-t get-text))
 
 (define/contract (string-indents str)
-  (string? . -> . (listof (or/c exact-positive-integer? #f)))
+  (string? . -> . (listof exact-nonnegative-integer?))
   (for/list ([line (in-list (string-split str "\n"))])
-            (define len (length (takef (string->list line) space-char?)))
-            (and (exact-positive-integer? len) len)))
+            (length (takef (string->list line) space-char?))))
 
 (module+ test
-  (check-equal? (string-indents t-str) '(#f 1 2)))
+  (check-equal? (string-indents t-str) '(0 1 2)))

beautiful-racket-lib/br/scribblings/br.scrbl

@@ -620,7 +620,7 @@ Convenient notation for @racket[(char textbox (line-end-visible textbox line-idx
 [textbox (is-a?/c text%)]
 [line-idx (or/c exact-nonnegative-integer? #f)])
 (or/c exact-nonnegative-integer? #f)]{
-Get the length of the indent of line @racket[line-idx] in @racket[textbox] (or @racket[#f] the line has no indent).
+Get the length of the indent of line @racket[line-idx] in @racket[textbox].
 }
 
 
@@ -634,7 +634,7 @@ Apply @racket[indenter-proc] to the text in @racket[textbox-or-str] and return a
 
 @defproc[(string-indents
 [str string?])
-(listof (or/c exact-positive-integer? #f))]{
+(listof exact-nonnegative-integer?)]{
 Lists the indents at the beginning of each line in @racket[str]. Useful for unit testing.
 }