complex.c: implement `Complex` addition and subtraction in C.

1 files changed, 44 insertions, 0 deletions

diff --git a/mrbgems/mruby-complex/src/complex.c b/mrbgems/mruby-complex/src/complex.c
index b4217d4d6..5243ac1cc 100644
--- a/mrbgems/mruby-complex/src/complex.c
+++ b/mrbgems/mruby-complex/src/complex.c
@@ -172,6 +172,48 @@ complex_eq(mrb_state *mrb, mrb_value x)
 }
 
 static mrb_value
+complex_add(mrb_state *mrb, mrb_value x)
+{
+  mrb_value y = mrb_get_arg1(mrb);
+  struct mrb_complex *p1 = complex_ptr(mrb, x);
+
+  switch (mrb_type(y)) {
+  case MRB_TT_COMPLEX:
+    {
+      struct mrb_complex *p2 = complex_ptr(mrb, y);
+      return mrb_complex_new(mrb, p1->real+p2->real, p1->imaginary+p2->imaginary);
+    }
+
+  default:
+    {
+      mrb_float z = mrb_to_flo(mrb, y);
+      return mrb_complex_new(mrb, p1->real+z, p1->imaginary);
+    }
+  }
+}
+
+static mrb_value
+complex_sub(mrb_state *mrb, mrb_value x)
+{
+  mrb_value y = mrb_get_arg1(mrb);
+  struct mrb_complex *p1 = complex_ptr(mrb, x);
+
+  switch (mrb_type(y)) {
+  case MRB_TT_COMPLEX:
+    {
+      struct mrb_complex *p2 = complex_ptr(mrb, y);
+      return mrb_complex_new(mrb, p1->real-p2->real, p1->imaginary-p2->imaginary);
+    }
+
+  default:
+    {
+      mrb_float z = mrb_to_flo(mrb, y);
+      return mrb_complex_new(mrb, p1->real-z, p1->imaginary);
+    }
+  }
+}
+
+static mrb_value
 complex_mul(mrb_state *mrb, mrb_value x)
 {
   mrb_value y = mrb_get_arg1(mrb);
@@ -386,6 +428,8 @@ void mrb_mruby_complex_gem_init(mrb_state *mrb)
   mrb_define_method(mrb, comp, "to_f", complex_to_f, MRB_ARGS_NONE());
   mrb_define_method(mrb, comp, "to_i", complex_to_i, MRB_ARGS_NONE());
   mrb_define_method(mrb, comp, "to_c", complex_to_c, MRB_ARGS_NONE());
+  mrb_define_method(mrb, comp, "+", complex_add, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, comp, "-", complex_sub, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, comp, "*", complex_mul, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, comp, "/", complex_div, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, comp, "quo", complex_div, MRB_ARGS_REQ(1));