fix port-bol? return type

cisco · Nov 7, 2023 · 3743324 · 3743324
1 parent ccdd5ec
commit 3743324
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Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/mats/6.ms b/mats/6.ms
@@ -713,6 +713,15 @@
   (call-with-input-file "testfile.ss"
     (lambda (p)
       (string=? (get-string-all p) "a\n\nbc\n")))
+  (let ([op (open-output-string)])
+    ;; disguise boolean? check just enough to prevent cp0 from folding
+    ;; based on the declared return type; we need to actually check it
+    (define (check) (assert (memq (port-bol? op) '(#t #f))) #t)
+    (check)
+    (fprintf op "okay\n")
+    (check)
+    (write-char #\x op)
+    (check))
  )
 
 (mat char-ready?

diff --git a/s/io.ss b/s/io.ss
@@ -214,7 +214,7 @@ implementation notes:
 
   (define eol-char?
     (lambda (c)
-      (memv c '(#\newline #\return #\nel #\ls))))
+      (and (memv c '(#\newline #\return #\nel #\ls)) #t)))
 
   (define-syntax port-gz-mode
     (syntax-rules ()