From 3adae7d2375e21e2009c93ff9f3690d1ebaca51f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?fn=20=E2=8C=83=20=E2=8C=A5?=
 <70830482+FnControlOption@users.noreply.github.com>
Date: Wed, 26 Oct 2022 08:55:29 -0700
Subject: [PATCH 1/2] mruby-compar-ext/compar.rb (clamp): fix range support.

Also, raise error if any comparison among min, max, and self
returns nil.
---
 mrbgems/mruby-compar-ext/mrblib/compar.rb | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/mrbgems/mruby-compar-ext/mrblib/compar.rb b/mrbgems/mruby-compar-ext/mrblib/compar.rb
index 3b1fdb7f8..18bba7919 100644
--- a/mrbgems/mruby-compar-ext/mrblib/compar.rb
+++ b/mrbgems/mruby-compar-ext/mrblib/compar.rb
@@ -43,13 +43,13 @@ module Comparable
   def clamp(min, max=nil)
     if max.nil?
       if min.kind_of?(Range)
-        max = min.begin
+        max = min.end
         if max.nil?
           max = self
         elsif min.exclude_end?
           raise ArgumentError, "cannot clamp with an exclusive range"
         end
-        min = min.end
+        min = min.begin
         if min.nil?
           min = self
         end
@@ -57,17 +57,24 @@ module Comparable
         raise TypeError, "wrong argument type #{min.class}"
       end
     end
-    if (min <=> max) > 0
+    c = min <=> max
+    if c.nil?
+      raise ArgumentError, "comparison of #{min.class} with #{max.class} failed"
+    elsif c > 0
       raise ArgumentError, "min argument must be smaller than max argument"
     end
     c = self <=> min
-    if c == 0
+    if c.nil?
+      raise ArgumentError, "comparison of #{self.class} with #{min.class} failed"
+    elsif c == 0
       return self
     elsif c < 0
       return min
     end
     c = self <=> max
-    if c > 0
+    if c.nil?
+      raise ArgumentError, "comparison of #{self.class} with #{max.class} failed"
+    elsif c > 0
       return max
     else
       return self

From c1697a9c4e1c82fec53b499e0e2d76271f8b351a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?fn=20=E2=8C=83=20=E2=8C=A5?=
 <70830482+FnControlOption@users.noreply.github.com>
Date: Wed, 26 Oct 2022 08:57:30 -0700
Subject: [PATCH 2/2] kernel.c (mrb_cmp_m): implement `Kernel#<=>`

---
 src/kernel.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/kernel.c b/src/kernel.c
index 73e28f468..59bdf1f9c 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -78,6 +78,16 @@ mrb_equal_m(mrb_state *mrb, mrb_value self)
   return mrb_bool_value(mrb_equal(mrb, self, arg));
 }
 
+static mrb_value
+mrb_cmp_m(mrb_state *mrb, mrb_value self)
+{
+  mrb_value arg = mrb_get_arg1(mrb);
+
+  if (mrb_obj_equal(mrb, self, arg))
+    return mrb_fixnum_value(0);
+  return mrb_nil_value();
+}
+
 /* 15.3.1.3.3  */
 /* 15.3.1.3.33 */
 /*
@@ -534,6 +544,7 @@ mrb_init_kernel(mrb_state *mrb)
 
 
   mrb_define_method(mrb, krn, "===",                        mrb_equal_m,                     MRB_ARGS_REQ(1));    /* 15.3.1.3.2  */
+  mrb_define_method(mrb, krn, "<=>",                        mrb_cmp_m,                       MRB_ARGS_REQ(1));
   mrb_define_method(mrb, krn, "block_given?",               mrb_f_block_given_p_m,           MRB_ARGS_NONE());    /* 15.3.1.3.6  */
   mrb_define_method(mrb, krn, "class",                      mrb_obj_class_m,                 MRB_ARGS_NONE());    /* 15.3.1.3.7  */
   mrb_define_method(mrb, krn, "clone",                      mrb_obj_clone,                   MRB_ARGS_NONE());    /* 15.3.1.3.8  */