rational.c: implement `Rational#/` and `#quo` in C.

mrbgems/mruby-rational/mrblib/rational.rb

@@ -7,18 +7,6 @@ class Rational < Numeric
     "#{numerator}/#{denominator}"
   end
 
-  def /(rhs)
-    if rhs.is_a? Rational
-      Rational(numerator * rhs.denominator, denominator * rhs.numerator)
-    elsif rhs.is_a? Integer
-      Rational(numerator, denominator * rhs)
-    elsif rhs.is_a? Numeric
-      numerator / rhs / denominator
-    end
-  end
-
-  alias quo /
-
   def <=>(rhs)
     case rhs
     when Integer, Float

mrbgems/mruby-rational/src/rational.c

@@ -545,6 +545,48 @@ rational_mul(mrb_state *mrb, mrb_value x)
 
 mrb_int mrb_num_div_int(mrb_state *, mrb_int, mrb_int);
 
+static mrb_value
+rational_div(mrb_state *mrb, mrb_value x)
+{
+  struct mrb_rational *p1 = rational_ptr(mrb, x);
+  mrb_value y = mrb_get_arg1(mrb);
+
+  switch (mrb_type(y)) {
+  case MRB_TT_INTEGER:
+    {
+      mrb_int z = mrb_integer(y);
+      if (mrb_int_mul_overflow(p1->denominator, z, &z)) rat_overflow(mrb);
+      return rational_new_i(mrb, p1->numerator, z);
+    }
+  case MRB_TT_RATIONAL:
+    {
+      struct mrb_rational *p2 = rational_ptr(mrb, y);
+      mrb_int a, b;
+
+      if (mrb_int_mul_overflow(p1->numerator, p2->denominator, &a)) rat_overflow(mrb);
+      if (mrb_int_mul_overflow(p2->numerator, p1->denominator, &b)) rat_overflow(mrb);
+      return rational_new_i(mrb, a, b);
+    }
+
+#if defined(MRB_USE_COMPLEX)
+  case MRB_TT_COMPLEX:
+    x = mrb_complex_new(mrb, rat_to_flo(p1), 0);
+    return mrb_funcall_id(mrb, x, MRB_OPSYM(div), 1, y);
+#endif
+
+  default:
+#ifndef MRB_NO_FLOAT
+  case MRB_TT_FLOAT:
+    {
+      mrb_float z = mrb_num_div_flo(mrb, p1->numerator, mrb_to_flo(mrb, y));
+      return mrb_float_value(mrb, mrb_num_div_flo(mrb, z, (mrb_float)p1->denominator));
+    }
+#else
+    mrb_raise(mrb, E_TYPE_ERROR, "non integer division");
+#endif
+  }
+}
+
 /* 15.2.8.3.4  */
 /*
  * redefine Integer#/
@@ -631,6 +673,8 @@ void mrb_mruby_rational_gem_init(mrb_state *mrb)
   mrb_define_method(mrb, rat, "+", rational_add, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, rat, "-", rational_sub, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, rat, "*", rational_mul, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, rat, "/", rational_div, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, rat, "quo", rational_div, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, mrb->integer_class, "to_r", fix_to_r, MRB_ARGS_NONE());
   mrb_define_method(mrb, mrb->integer_class, "/", int_div, MRB_ARGS_REQ(1)); /* overrride */
   mrb_define_method(mrb, mrb->integer_class, "quo", int_quo, MRB_ARGS_REQ(1)); /* overrride */