Change printed representation of inf/nan to match R7RS.

diff --git a/src/runtime/dragon4.scm b/src/runtime/dragon4.scm
index 35883f18be6d50358aead0b80f10176068c4a76d..14e13a5dbb7e4fede08f33e888d3c9ecd382d8b3 100644 (file)
--- a/src/runtime/dragon4.scm
+++ b/src/runtime/dragon4.scm
@@ -66,11 +66,7 @@ not much different to numbers within a few orders of magnitude of 1.
   unspecific)
 \f
 (define (flo:->string x radix)
-  (let ((inf?
-        (lambda (x)
-          (and (flo:> x 1.)
-               (flo:= x (flo:/ x 2.)))))
-       (x>0
+  (let ((x>0
         (lambda (x)
           (let ((p flo:significand-digits-base-2))
             (call-with-values (lambda () (dragon4-normalize x p))
@@ -90,20 +86,21 @@ not much different to numbers within a few orders of magnitude of 1.
                           (display-procedure digits k radix))))))))))))
     (or (and flonum-unparser-hook
             (flonum-unparser-hook x radix))
-       (cond ((flo:positive? x)
-              (if (inf? x)
-                  (string-copy "#[+inf]")
+       (cond ((flo:nan? x)
+              (string-copy "+nan.0"))
+             ((flo:positive? x)
+              (if (flo:inf? x)
+                  (string-copy "+inf.0")
                   (x>0 x)))
              ((flo:negative? x)
               (let ((x (flo:negate x)))
-                (if (inf? x)
-                    (string-copy "#[-inf]")
+                (if (flo:inf? x)
+                    (string-copy "-inf.0")
                     (string-append "-" (x>0 x)))))
              ((flo:zero? x)
-              ;; XXX Kludgey test for zero sign.
-              (string-copy (if (flo:negative? (flo:atan2 x -1.)) "-0." "0.")))
+              (string-copy (if (flo:safe-negative? x) "-0." "0.")))
              (else
-              (string-copy "#[NaN]"))))))
+              (string-copy "+nan.0"))))))
 
 (define (flonum-unparser:normal-output digits k radix)
   (let ((k+1 (+ k 1)))