* ext/bigdecimal/bigdecimal.c (BigDecimal_save_exception_mode,

BigDecimal_save_rounding_mode, BigDecimal_save_limit): added.
* test/bigdecimal/test_bigdecimal.rb: added tests for the above
  features.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29127 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,11 @@
+Sat Aug 28 17:39:33 2010  Kenta Murata  <mrkn@mrkn.jp>
+
+	* ext/bigdecimal/bigdecimal.c (BigDecimal_save_exception_mode,
+	  BigDecimal_save_rounding_mode, BigDecimal_save_limit): added.
+
+	* test/bigdecimal/test_bigdecimal.rb: added tests for the above
+	  features.
+
 Sat Aug 28 08:11:05 2010  Tanaka Akira  <akr@fsij.org>
 
 	* ext/pathname/pathname.c (path_blockdev_p): Pathname#blockdev?

ext/bigdecimal/bigdecimal.c

@@ -1800,6 +1800,48 @@ BigDecimal_sign(VALUE self)
     return INT2FIX(s);
 }
 
+/* call-seq:
+ * BigDecimal.save_exception_mode { ... }
+ */
+static VALUE
+BigDecimal_save_exception_mode(VALUE self)
+{
+    unsigned short const exception_mode = VpGetException();
+    int state;
+    VALUE ret = rb_protect(rb_yield, Qnil, &state);
+    VpSetException(exception_mode);
+    if (state) rb_jump_tag(state);
+    return ret;
+}
+
+/* call-seq:
+ * BigDecimal.save_rounding_mode { ... }
+ */
+static VALUE
+BigDecimal_save_rounding_mode(VALUE self)
+{
+    unsigned short const round_mode = VpGetRoundMode();
+    int state;
+    VALUE ret = rb_protect(rb_yield, Qnil, &state);
+    VpSetRoundMode(round_mode);
+    if (state) rb_jump_tag(state);
+    return Qnil;
+}
+
+/* call-seq:
+ * BigDecimal.save_limit { ... }
+ */
+static VALUE
+BigDecimal_save_limit(VALUE self)
+{
+    size_t const limit = VpGetPrecLimit();
+    int state;
+    VALUE ret = rb_protect(rb_yield, Qnil, &state);
+    VpSetPrecLimit(limit);
+    if (state) rb_jump_tag(state);
+    return Qnil;
+}
+
 /* Document-class: BigDecimal
  * BigDecimal provides arbitrary-precision floating point decimal arithmetic.
  *
@@ -1926,6 +1968,10 @@ Init_bigdecimal(void)
     rb_define_singleton_method(rb_cBigDecimal, "_load", BigDecimal_load, 1);
     rb_define_singleton_method(rb_cBigDecimal, "ver", BigDecimal_version, 0);
 
+    rb_define_singleton_method(rb_cBigDecimal, "save_exception_mode", BigDecimal_save_exception_mode, 0);
+    rb_define_singleton_method(rb_cBigDecimal, "save_rounding_mode", BigDecimal_save_rounding_mode, 0);
+    rb_define_singleton_method(rb_cBigDecimal, "save_limit", BigDecimal_save_limit, 0);
+
     /* Constants definition */
 
     /*

test/bigdecimal/test_bigdecimal.rb

@@ -77,6 +77,42 @@ class TestBigDecimal < Test::Unit::TestCase
     end
   end
 
+  def test_save_exception_mode
+    BigDecimal.mode(BigDecimal::EXCEPTION_OVERFLOW, false)
+    mode = BigDecimal.mode(BigDecimal::EXCEPTION_OVERFLOW)
+    BigDecimal.save_exception_mode do
+      BigDecimal.mode(BigDecimal::EXCEPTION_OVERFLOW, true)
+    end
+    assert_equal(mode, BigDecimal.mode(BigDecimal::EXCEPTION_OVERFLOW))
+
+    BigDecimal.mode(BigDecimal::ROUND_MODE, BigDecimal::ROUND_FLOOR)
+    BigDecimal.save_exception_mode do
+      BigDecimal.mode(BigDecimal::ROUND_MODE, BigDecimal::ROUND_HALF_EVEN)
+    end
+    assert_equal(BigDecimal::ROUND_HALF_EVEN, BigDecimal.mode(BigDecimal::ROUND_MODE))
+  end
+
+  def test_save_rounding_mode
+    BigDecimal.mode(BigDecimal::ROUND_MODE, BigDecimal::ROUND_FLOOR)
+    BigDecimal.save_rounding_mode do
+      BigDecimal.mode(BigDecimal::ROUND_MODE, BigDecimal::ROUND_HALF_EVEN)
+    end
+    assert_equal(BigDecimal::ROUND_FLOOR, BigDecimal.mode(BigDecimal::ROUND_MODE))
+  end
+
+  def test_save_limit
+    begin
+      old = BigDecimal.limit
+      BigDecimal.limit(100)
+      BigDecimal.save_limit do
+        BigDecimal.limit(200)
+      end
+      assert_equal(100, BigDecimal.limit);
+    ensure
+      BigDecimal.limit(old)
+    end
+  end
+
   def test_exception_nan
     _test_mode(BigDecimal::EXCEPTION_NaN) { BigDecimal.new("NaN") }
   end