From 093ac69a6a7dfc8476d295a03ca18e930f8fae29 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Wed, 21 Dec 2016 11:57:15 -0800
Subject: [PATCH] br/indent adjustments

---
 beautiful-racket-lib/br/indent.rkt            | 15 ++++++--
 .../br/demo/jsonic-2/indenter.rkt             | 34 +++++++++++--------
 2 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/beautiful-racket-lib/br/indent.rkt b/beautiful-racket-lib/br/indent.rkt
index 9415bb0..a51a54a 100644
--- a/beautiful-racket-lib/br/indent.rkt
+++ b/beautiful-racket-lib/br/indent.rkt
@@ -121,6 +121,14 @@
   (check-equal? (line-start-visible t 2) 10)
   (check-equal? (line-start-visible t 3) #f))
 
+(define/contract (line-first-visible-char text line)
+  ((is-a?/c text%) (or/c exact-nonnegative-integer? #f) . -> . (or/c char? #f))
+  (char text (line-start-visible text line)))
+
+(define/contract (line-last-visible-char text line)
+  ((is-a?/c text%) (or/c exact-nonnegative-integer? #f) . -> . (or/c char? #f))
+  (char text (line-end-visible text line)))  
+
 (define/contract (line-end-visible text line)
   ((is-a?/c text%) (or/c exact-nonnegative-integer? #f) . -> . (or/c exact-nonnegative-integer? #f))
   (define start+1 (line-end text line)) ; start before newline
@@ -185,9 +193,10 @@
   (send indented-t get-text))
 
 (define/contract (string-indents str)
-  (string? . -> . (listof exact-nonnegative-integer?))
+  (string? . -> . (listof (or/c exact-positive-integer? #f)))
   (for/list ([line (in-list (string-split str "\n"))])
-            (length (takef (string->list line) space-char?))))
+            (define len (length (takef (string->list line) space-char?)))
+            (and (exact-positive-integer? len) len)))
 
 (module+ test
-  (check-equal? (string-indents t-str) '(0 1 2)))
\ No newline at end of file
+  (check-equal? (string-indents t-str) '(#f 1 2)))
\ No newline at end of file
diff --git a/beautiful-racket/br/demo/jsonic-2/indenter.rkt b/beautiful-racket/br/demo/jsonic-2/indenter.rkt
index 426b2b6..23a2ba7 100644
--- a/beautiful-racket/br/demo/jsonic-2/indenter.rkt
+++ b/beautiful-racket/br/demo/jsonic-2/indenter.rkt
@@ -3,32 +3,33 @@
 (provide indent-jsonic)
 
 (define indent-width 2)
-
-(define (left-bracket? c) (member c '(#\{ #\[)))
-(define (right-bracket? c) (member c '(#\} #\])))
+(define (left-bracket? c) (member c (list #\{ #\[)))
+(define (right-bracket? c) (member c (list #\} #\])))
 
 ;; if this line begins with } or ], outdent.
 ;; if last line begins with { or [, indent.
 ;; otherwise use previous indent
-(define/contract (indent-jsonic textbox [tbpos 0])
+(define/contract (indent-jsonic tbox [posn 0])
   ((is-a?/c text%) exact-nonnegative-integer?  . -> .
                    (or/c exact-nonnegative-integer? #f))
-  (define this-line (line textbox tbpos))
-  (define prev-line (previous-line textbox tbpos))
-  (define prev-indent (or (line-indent textbox prev-line) 0))
-  (define this-indent
+  (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
     (cond
-      [(left-bracket? (char textbox (line-start-visible textbox prev-line)))
+      [(left-bracket?
+        (line-first-visible-char tbox prev-line))
        (+ prev-indent indent-width)]
-      [(right-bracket? (char textbox (line-start-visible textbox this-line)))
+      [(right-bracket?
+        (line-first-visible-char tbox current-line))
        (- prev-indent indent-width)]
       [else prev-indent]))
-  (and (exact-positive-integer? this-indent) this-indent))
+  (and (exact-positive-integer? current-indent) current-indent))
 
 (module+ test
   (require rackunit)
-  (define test-str #<<here
-#lang br/demo/jsonic
+  (define test-str #<<HERE
+#lang jsonic
 {
 "value",
 "string":
@@ -40,6 +41,9 @@
 ]
 // "bar"
 }
-here
+HERE
     )
-  (display (apply-indenter indent-jsonic test-str)))
+  (check-equal?
+   (string-indents (apply-indenter indent-jsonic test-str))
+   '(#f #f 2 2 2 4 6 6 4 2 2 #f)))
+