change 18386a9 to use a different strategy to get the end point of the #lang line

Author: rfindler

drracket/drracket/private/rep.rkt

@@ -2419,69 +2419,8 @@ TODO
     (check-equal? (simplify-history-element in #t)
                   (old-conversion-code in))))
 
-(define (fetch-hash-lang-str text)
-  (define special-tp (open-input-text-editor text))
-  (define (special-filter f bytes)
-    ;; @ is not accepted anywhere in the regexp below
-    (bytes-set! bytes 0 (char->integer #\@))
-    1)
-  (define tp (special-filter-input-port special-tp special-filter))
-  (port-count-lines! tp)
-  (skip-past-comments tp)
-  (define-values (_1 _2 pos-before) (port-next-location tp))
-  (cond
-    [(regexp-match? #rx"^#lang [a-zA-Z0-9+_/-]+" tp)
-     (define c (peek-char tp))
-     (cond
-       [(eof-object? c)
-        (define-values (line col pos-after) (port-next-location tp))
-        (send text get-text (- pos-before 1) pos-after)]
-       [(char-whitespace? c)
-        (define-values (line col pos-after) (port-next-location tp))
-        (send text get-text (- pos-before 1) (- pos-after 1))]
-       [else #f])]
-    [else #f]))
-
-(module+ test
-  (check-equal? (let ([t (new text%)])
-                  (send t insert "blah")
-                  (fetch-hash-lang-str t))
-                #f)
-  (check-equal? (let ([t (new text%)])
-                  (send t insert "#lang racket")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert " #lang racket")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert "#lang racket ")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert "#lang racket\n")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert "#lang racket fjd ej ej")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert ";; a\n#lang racket fjd ej ej")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert ";; a")
-                  (define es (new editor-snip%))
-                  (send t insert es)
-                  (send t insert "\n#lang racket")
-                  (fetch-hash-lang-str t))
-                "#lang racket")
-  (check-equal? (let ([t (new text%)])
-                  (send t insert "#lang rac")
-                  (define es (new editor-snip%))
-                  (send t insert es)
-                  (send t insert "ket\n")
-                  (fetch-hash-lang-str t))
-                #f))
+(define (fetch-hash-lang-str definitions-text)
+  (define the-irl (send definitions-text get-irl))
+  (define-values (before after)
+    (get-read-language-port-start+end (send definitions-text get-irl)))
+  (and after (send definitions-text get-text 0 after)))