Include +inf.0 and -inf.0 in conversions of Rational to SCM and back

[lilypond.git] / lily / lily-guile.cc

diff --git a/lily/lily-guile.cc b/lily/lily-guile.cc
index 7985b35d90e850a9f67152f7a22e4d22e83bbc13..6ddcad079ba749924f0a6d93cd4b56253e48675d 100644 (file)
--- a/lily/lily-guile.cc
+++ b/lily/lily-guile.cc
@@ -580,6 +580,12 @@ robust_scm2vsize (SCM k, vsize o)
 SCM
 ly_rational2scm (Rational r)
 {
+  if (r.is_infinity ())
+    if (r > Rational(0))
+      return scm_inf ();
+    else
+      return scm_difference (scm_inf (), SCM_UNDEFINED);
+
   return scm_divide (scm_from_int64 (r.numerator ()),
                      scm_from_int64 (r.denominator ()));
 }
@@ -587,6 +593,22 @@ ly_rational2scm (Rational r)
 Rational
 ly_scm2rational (SCM r)
 {
+  if (scm_is_true (scm_inf_p (r)))
+    {
+      if (scm_is_true (scm_positive_p (r)))
+       {
+         Rational r;
+         r.set_infinite (1);
+         return r;
+       }
+      else
+       {
+         Rational r;
+         r.set_infinite (-1);
+         return r;
+       }
+    }
+
   return Rational (scm_to_int64 (scm_numerator (r)),
                    scm_to_int64 (scm_denominator (r)));
 }
@@ -594,7 +616,9 @@ ly_scm2rational (SCM r)
 Rational
 robust_scm2rational (SCM n, Rational rat)
 {
-  if (ly_is_fraction (n))
+  if (scm_is_real (n)
+      && (scm_is_true (scm_exact_p (n))
+         || scm_is_true (scm_inf_p (n))))
     return ly_scm2rational (n);
   else
     return rat;