From 89dac0bc8cf7c40e0ddb626a4af5b3782905265d Mon Sep 17 00:00:00 2001
From: akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 5 Dec 2007 09:12:58 +0000
Subject: * numeric.c (int_odd_p): new method Integer#odd?.   (int_even_p): new
 method Integer#even?.   (int_pred): new method Integer#pred.   (fix_odd_p):
 new method Fixnum#odd?.   (fix_even_p): new method Fixnum#even?.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@14111 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 numeric.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 90 insertions(+), 9 deletions(-)

(limited to 'numeric.c')

diff --git a/numeric.c b/numeric.c
index 9d2c4508ac..b588081f23 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1784,6 +1784,39 @@ int_int_p(num)
     return Qtrue;
 }
 
+/*
+ *  call-seq:
+ *     int.odd? -> true or false
+ *
+ *  Returns <code>true</code> if <i>int</i> is an odd number.
+ */
+
+static VALUE
+int_odd_p(VALUE num)
+{
+    if (rb_funcall(num, '%', 1, INT2FIX(2)) != INT2FIX(0)) {
+        return Qtrue;
+    }
+    return Qfalse;
+}
+
+/*
+ *  call-seq:
+ *     int.even? -> true or false
+ *
+ *  Returns <code>true</code> if <i>int</i> is an even number.
+ */
+
+static VALUE
+int_even_p(VALUE num)
+{
+    if (rb_funcall(num, '%', 1, INT2FIX(2)) == INT2FIX(0)) {
+        return Qtrue;
+    }
+    return Qfalse;
+}
+
+
 /*
  *  call-seq:
  *     int.next    => integer
@@ -1806,6 +1839,26 @@ int_succ(num)
     return rb_funcall(num, '+', 1, INT2FIX(1));
 }
 
+/*
+ *  call-seq:
+ *     int.pred    => integer
+ *
+ *  Returns the <code>Integer</code> equal to <i>int</i> - 1.
+ *
+ *     1.pred      #=> 0
+ *     (-1).pred   #=> -2
+ */
+
+static VALUE
+int_pred(VALUE num)
+{
+    if (FIXNUM_P(num)) {
+        long i = FIX2LONG(num) - 1;
+        return LONG2NUM(i);
+    }
+    return rb_funcall(num, '-', 1, INT2FIX(1));
+}
+
 /*
  *  call-seq:
  *     int.chr    => string
@@ -2262,15 +2315,6 @@ int_pow(x, y)
     return LONG2NUM(z);
 }
 
-static VALUE
-int_even_p(VALUE num)
-{
-    if (rb_funcall(num, '%', 1, INT2FIX(2)) == INT2FIX(0)) {
-	return Qtrue;
-    }
-    return Qfalse;
-}
-
 /*
  *  call-seq:
  *    fix ** other         => Numeric
@@ -2907,6 +2951,38 @@ fix_zero_p(num)
     return Qfalse;
 }
 
+/*
+ *  call-seq:
+ *     fix.odd? -> true or false
+ *
+ *  Returns <code>true</code> if <i>fix</i> is an odd number.
+ */
+
+static VALUE
+fix_odd_p(VALUE num)
+{
+    if (num & 2) {
+        return Qtrue;
+    }
+    return Qfalse;
+}
+
+/*
+ *  call-seq:
+ *     fix.even? -> true or false
+ *
+ *  Returns <code>true</code> if <i>fix</i> is an even number.
+ */
+
+static VALUE
+fix_even_p(VALUE num)
+{
+    if (num & 2) {
+        return Qfalse;
+    }
+    return Qtrue;
+}
+
 void
 Init_Numeric()
 {
@@ -2961,12 +3037,15 @@ Init_Numeric()
     rb_undef_method(CLASS_OF(rb_cInteger), "new");
 
     rb_define_method(rb_cInteger, "integer?", int_int_p, 0);
+    rb_define_method(rb_cInteger, "odd?", int_odd_p, 0);
+    rb_define_method(rb_cInteger, "even?", int_even_p, 0);
     rb_define_method(rb_cInteger, "upto", int_upto, 1);
     rb_define_method(rb_cInteger, "downto", int_downto, 1);
     rb_define_method(rb_cInteger, "times", int_dotimes, 0);
     rb_include_module(rb_cInteger, rb_mPrecision);
     rb_define_method(rb_cInteger, "succ", int_succ, 0);
     rb_define_method(rb_cInteger, "next", int_succ, 0);
+    rb_define_method(rb_cInteger, "pred", int_pred, 0);
     rb_define_method(rb_cInteger, "chr", int_chr, 0);
     rb_define_method(rb_cInteger, "ord", int_ord, 0);
     rb_define_method(rb_cInteger, "to_i", int_to_i, 0);
@@ -3020,6 +3099,8 @@ Init_Numeric()
     rb_define_method(rb_cFixnum, "to_f", fix_to_f, 0);
     rb_define_method(rb_cFixnum, "size", fix_size, 0);
     rb_define_method(rb_cFixnum, "zero?", fix_zero_p, 0);
+    rb_define_method(rb_cFixnum, "odd?", fix_odd_p, 0);
+    rb_define_method(rb_cFixnum, "even?", fix_even_p, 0);
 
     rb_cFloat  = rb_define_class("Float", rb_cNumeric);
 
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