Issue 2692: Let ly:make-moment accept rationals for main and grace timing

For compatibility reasons, it remains possible to write two numbers
specifying numerator and denominator instead of the rationals.  These
forms cannot be mixed, and the two-argument form is disambiguated by
the sign of the second argument: if it is positive, it can only be a
denominator and not a grace timing.

diff --git a/lily/moment-scheme.cc b/lily/moment-scheme.cc
index 3347c4da23ae0c077b84819f98762b1f36e4d92f..2d81e8075e6c554c8544cfe76a82b0d61f78ab17 100644 (file)
--- a/lily/moment-scheme.cc
+++ b/lily/moment-scheme.cc
@@ -21,33 +21,53 @@
 
 /* TODO: add optional factor argument. */
 LY_DEFINE (ly_make_moment, "ly:make-moment",
-           2, 2, 0, (SCM n, SCM d, SCM gn, SCM gd),
-           "Create the rational number with main timing @var{n}/@var{d},"
-           " and optional grace timing @var{gn}/@var{gd}.\n"
+           1, 3, 0, (SCM m, SCM g, SCM gn, SCM gd),
+           "Create the moment with rational main timing @var{m},"
+           " and optional grace timing @var{g}.\n"
            "\n"
            "A @dfn{moment} is a point in musical time.  It consists of"
            " a pair of rationals (@var{m},@tie{}@var{g}), where @var{m} is"
            " the timing for the main notes, and @var{g} the timing for"
-           " grace notes.  In absence of grace notes, @var{g}@tie{}is zero.")
+           " grace notes.  In absence of grace notes, @var{g}@tie{}is zero.\n"
+          "\n"
+          "For compatibility reasons, it is possible to write two"
+          " numbers specifying numerator and denominator instead of"
+           " the rationals.  These forms cannot be mixed, and the two-"
+          "argument form is disambiguated by the sign of the second"
+          " argument: if it is positive, it can only be a denominator"
+          " and not a grace timing."
+)
 {
-  LY_ASSERT_TYPE (scm_is_integer, n, 1);
-  LY_ASSERT_TYPE (scm_is_integer, d, 2);
+  LY_ASSERT_TYPE (ly_is_rational, m, 1);
+  if (SCM_UNBNDP (g))
+    return Moment (ly_scm2rational (m)).smobbed_copy ();
 
-  int grace_num = 0;
-  if (gn != SCM_UNDEFINED)
+  if (SCM_UNBNDP (gn))
     {
-      LY_ASSERT_TYPE (scm_is_integer, gn, 3);
-      grace_num = scm_to_int (gn);
+      LY_ASSERT_TYPE (ly_is_rational, g, 2);
+      if (scm_is_true (scm_positive_p (g)))
+       {
+         LY_ASSERT_TYPE (scm_is_integer, m, 1);
+         LY_ASSERT_TYPE (scm_is_integer, g, 2);
+         return Moment (Rational (scm_to_int64 (m),
+                                  scm_to_int64 (g))).smobbed_copy ();
+       }
+      return Moment (ly_scm2rational (m),
+                    ly_scm2rational (g)).smobbed_copy ();
     }
 
-  int grace_den = 1;
-  if (gd != SCM_UNDEFINED)
+  LY_ASSERT_TYPE (scm_is_integer, m, 1);
+  LY_ASSERT_TYPE (scm_is_integer, g, 2);
+  LY_ASSERT_TYPE (scm_is_integer, gn, 3);
+  I64 grace_num = scm_to_int64 (gn);
+  I64 grace_den = 1;
+  if (!SCM_UNBNDP (gd))
     {
       LY_ASSERT_TYPE (scm_is_integer, gd, 4);
-      grace_den = scm_to_int (gd);
+      grace_den = scm_to_int64 (gd);
     }
 
-  return Moment (Rational (scm_to_int (n), scm_to_int (d)),
+  return Moment (Rational (scm_to_int64 (m), scm_to_int64 (g)),
                  Rational (grace_num, grace_den)).smobbed_copy ();
 }