This is a multi-part message in MIME format.

------extPart_000_0001_01C20044.520439E0
Content-Type: text/plain;
	charsets-ascii"
Content-Transfer-Encoding: 7bit

"Yukihiro Matsumoto" <matz / ruby-lang.org> wrote in
...
> |  module Comparable
> |    def <(other)
> |      result  elf <other
> |      return result.nil? ? false : result
> |    end
> |  end
> |
> |Thus <could have five possible results:
> |    -1       less than
> |     0       equal
> |     1       greater than
> |    nil      none of the above
> |  exception  an exceptional condition (error) occurred
>
> Hmm, I like this one.  Let me consider.

Yes please;-)  The included patch for ``compare.c'' implements
this. The cosmetic object.c patch is for consistency only and
not necessary  (Module#<is not a partial order anyway).


/Christoph


------extPart_000_0001_01C20044.520439E0
Content-Type: application/octet-stream;
	name
ompar.diff"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment;
	filename
ompar.diff"

--- compar.c.1.11	Mon May 20 15:48:27 2002
+++ compar.c	Mon May 20 18:28:08 2002
@@ -17,32 +17,13 @@
tatic ID cmp;
0Atatic VALUE
-cmp_eq(a)
-    VALUE *a;
-{
-    VALUE c = rb_funcall(a[0], cmp, 1, a[1]);
-    int t = NUM2INT(c);
-
-    if (t == 0) return Qtrue;
-    return Qfalse;
-}
-
-static VALUE
-cmp_failed()
-{
-    return Qfalse;
-}
-
-static VALUE
mp_equal(x, y)
ALUE x, y;

-    VALUE a[2];
-
-    if (x == y) return Qtrue;
+    VALUE c = rb_funcall(x, cmp, 1, y);
0A-    a[0] = x; a[1] = y;
-    return rb_rescue(cmp_eq, (VALUE)a, cmp_failed, 0);
+    if (!NIL_P((c)) && NUM2LONG(c) == 0) return Qtrue;
+    return Qfalse;

0Atatic VALUE
@@ -50,9 +31,8 @@
ALUE x, y;

ALUE c = rb_funcall(x, cmp, 1, y);
-    int t = NUM2INT(c);
0A-    if (t > 0) return Qtrue;
+    if (!NIL_P(c) && NUM2LONG(c) > 0) return Qtrue;
eturn Qfalse;

0A@@ -61,9 +41,8 @@
ALUE x, y;

ALUE c = rb_funcall(x, cmp, 1, y);
-    int t = NUM2INT(c);
0A-    if (t >= 0) return Qtrue;
+    if (!NIL_P(c) && NUM2LONG(c) >= 0) return Qtrue;
eturn Qfalse;

0A@@ -72,9 +51,8 @@
ALUE x, y;

ALUE c = rb_funcall(x, cmp, 1, y);
-    int t = NUM2INT(c);
0A-    if (t < 0) return Qtrue;
+    if (!NIL_P(c) && NUM2LONG(c) < 0) return Qtrue;
eturn Qfalse;

0A@@ -83,9 +61,8 @@
ALUE x, y;

ALUE c = rb_funcall(x, cmp, 1, y);
-    int t = NUM2INT(c);
0A-    if (t <= 0) return Qtrue;
+    if (!NIL_P(c) && NUM2LONG(c) <= 0) return Qtrue;
eturn Qfalse;

0A@@ -94,14 +71,22 @@
ALUE x, min, max;

ALUE c = rb_funcall(x, cmp, 1, min);
-    long t = NUM2LONG(c);
-    if (t < 0) return Qfalse;
+    VALUE d = rb_funcall(x, cmp, 1, max);
0A-    c = rb_funcall(x, cmp, 1, max);
-    t = NUM2LONG(c);
-    if (t > 0) return Qfalse;
+    if (NIL_P(c)) {
+      if (NIL_P(d) || NUM2LONG(d)) return Qfalse;
+    } else {
+      long s = NUM2LONG(c);
+      if (NIL_P(d)) {
+        return Qfalse;
+      } else {
+        long t = NUM2LONG(d);
+        if (s <= 0 || t >= 0) return Qfalse;
+      }
+    }
eturn Qtrue;
-}
+};
+
0Aoid
nit_Comparable()
-----extPart_000_0001_01C20044.520439E0
Content-Type: application/octet-stream;
	namebject.diff"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment;
	filenamebject.diff"

--- object.c.1.78	Mon May 20 15:47:10 2002
+++ object.c	Mon May 20 15:53:56 2002
@@ -604,7 +604,6 @@
return INT2FIX(1);
arg = RCLASS(arg)->super;

-    rb_raise(rb_eArgError, "non related class/module");
eturn Qnil;		/* not reached */

0A@@ -872,7 +871,7 @@
NIL_P(val) ? "nil" :
val == Qtrue ? "true" :
val == Qfalse ? "false" :
-		     rb_class2name(CLASS_OF(val)), 
+		     rb_class2name(CLASS_OF(val)),
tname);
}
else {
@@ -1232,7 +1231,7 @@
b_define_method(rb_mKernel, "nil?", rb_false, 0);
b_define_method(rb_mKernel, "==", rb_obj_equal, 1);
b_define_method(rb_mKernel, "equal?", rb_obj_equal, 1);
-    rb_define_method(rb_mKernel, "===", rb_obj_equal, 1); 
+    rb_define_method(rb_mKernel, "===", rb_obj_equal, 1);
b_define_method(rb_mKernel, "=~", rb_false, 1);
0Ab_define_method(rb_mKernel, "eql?", rb_obj_equal, 1);
-----extPart_000_0001_01C20044.520439E0
Content-Type: application/octet-stream;
	name
omp_test.rb"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment;
	filename
omp_test.rb"

class A
def initialize(a)
@a = a
end
include Comparable
attr_reader :a
def <=> (other)
@a <=> other.a rescue nil 
end
end

x = A.new -10
y = A.new 4.5
z = A.new 'z'

p  ([x < y,x <=y, x == y, x >= y, x > y] == \
[true, true, false,false,false ])

p  ([y < x,y <=x, y == x, y >= x, y > x] == \
[false,false,false, true, true])

p  ([-10.0,1,4.5,'a'].collect {|n| (A.new n).between? (x,y) } == \
[false,true,false,false])

p ([-10.0,1,4.5,'a'].collect {|n| (A.new n).between? (y,x) } == \
false,false,false,false])


x = A.new 'x'

p  ([x < y,x <=y, x == y, x >= y, x > y] == \
[false, false, false,false,false ])


def x.<=>(other) 
'42' unless other.a == 'z' 
end
0A
p [ proc { x < y  },
proc { x <=y  },
proc { x == y }, 
proc { x >= y },
proc { x > y  },
proc { x.between?(z,y) },
proc { x.between?(y,z) }
].collect {|l| 
begin 
l.call
rescue => mes
mes.type 
end
} == Array.new(7) {TypeError} 
-----extPart_000_0001_01C20044.520439E0--