From 749d4b6a0ceb4855b55bfbdf9e5f23802a4ca6b7 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Sun, 7 Jan 2024 19:29:20 -0800
Subject: [PATCH] Issue #519 - Properly handle doubles in remainder

---
 runtime.c      | 24 ++++++++++++++++++------
 tests/base.scm |  8 +++-----
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/runtime.c b/runtime.c
index 195cac19..fa16c719 100644
--- a/runtime.c
+++ b/runtime.c
@@ -4629,6 +4629,7 @@ void Cyc_bignum_remainder(void *data, object cont, object num1, object num2, obj
 void Cyc_remainder(void *data, object cont, object num1, object num2)
 {
   int i = 0, j = 0;
+  double ii = 0, jj = 0;
   object result;
   if (obj_is_int(num1)) {
     if (obj_is_int(num2)){
@@ -4641,8 +4642,9 @@ void Cyc_remainder(void *data, object cont, object num1, object num2)
       Cyc_bignum_remainder(data, cont, bn, num2, bn);
     }
     else if (is_object_type(num2) && type_of(num2) == double_tag){
-      i = obj_obj2int(num1);
-      j = ((double_type *)num2)->value; 
+      ii = obj_obj2int(num1);
+      jj = ((double_type *)num2)->value; 
+      goto handledouble;
     }
     else {
       goto typeerror;
@@ -4658,6 +4660,7 @@ void Cyc_remainder(void *data, object cont, object num1, object num2)
       Cyc_bignum_remainder(data, cont, num1, num2, rem);
     }
     else if (is_object_type(num2) && type_of(num2) == double_tag){
+      // TODO: correct to convert bignum to double here
       j = ((double_type *)num2)->value; 
       alloc_bignum(data, bn);
       Cyc_int2bignum(obj_obj2int(j), &(bn->bn));
@@ -4668,18 +4671,21 @@ void Cyc_remainder(void *data, object cont, object num1, object num2)
     }
   } else if (is_object_type(num1) && type_of(num1) == double_tag){
     if (obj_is_int(num2)){
-      i = ((double_type *)num1)->value; 
-      j = obj_obj2int(num2);
+      ii = ((double_type *)num1)->value; 
+      jj = obj_obj2int(num2);
+      goto handledouble;
     }
     else if (is_object_type(num2) && type_of(num2) == bignum_tag){
+      // TODO: convert bignum to double here
       i = ((double_type *)num1)->value; 
       alloc_bignum(data, bn);
       Cyc_int2bignum(obj_obj2int(i), &(bn->bn));
       Cyc_bignum_remainder(data, cont, bn, num2, bn);
     }
     else if (is_object_type(num2) && type_of(num2) == double_tag){
-      i = ((double_type *)num1)->value; 
-      j = ((double_type *)num2)->value; 
+      ii = ((double_type *)num1)->value; 
+      jj = ((double_type *)num2)->value; 
+      goto handledouble;
     } 
     else {
       goto typeerror;
@@ -4690,6 +4696,12 @@ void Cyc_remainder(void *data, object cont, object num1, object num2)
   if (j == 0) { Cyc_rt_raise_msg(data, "Divide by zero"); }
   result = obj_int2obj(i % j);
   return_closcall1(data, cont, result); 
+handledouble:
+{
+  if (jj == 0) { Cyc_rt_raise_msg(data, "Divide by zero"); }
+  make_double(dresult, fmod(ii, jj));
+  return_closcall1(data, cont, &dresult); 
+}
 typeerror:
   {
     make_string(s, "Bad argument type");
diff --git a/tests/base.scm b/tests/base.scm
index 48aa601a..3fea3896 100644
--- a/tests/base.scm
+++ b/tests/base.scm
@@ -75,8 +75,7 @@
   (test (values -2 -1) (truncate/ -5 2))
   (test (values -2 1) (truncate/ 5 -2))
   (test (values 2 -1) (truncate/ -5 -2))
-; TODO:
-;  (test (values 2.0 -1.0) (truncate/ -5.0 -2))
+  (test (values 2.0 -1.0) (truncate/ -5.0 -2))
 
   (test 4 (gcd 32 -36))
   (test 0 (gcd))
@@ -95,9 +94,8 @@
   (test 4.0  (round 7/2)) ;; Rationals not supported, so result is inexact
   (test 7    (round 7))
 
-  ; TODO: 
-  ;(test 3 (numerator (/ 6 4)))
-  ;(test 2 (denominator (/ 6 4)))
+  (test 3.0 (numerator (/ 6 4))) ;; Inexact because we don't support rationals yet
+  (test 2.0 (denominator (/ 6 4))) ;; Inexact because we don't support rationals yet
   (test 2.0 (denominator (inexact (/ 6 4))))
 )