* array.c (rb_ary_sum): Support the optional argument, init, and block.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54577 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Thu Apr 14 21:46:36 2016  Tanaka Akira  <akr@fsij.org>
+
+	* array.c (rb_ary_sum): Support the optional argument, init, and
+	  block.
+
 Thu Apr 14 19:02:41 2016  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/irb/ext/save-history.rb: suppress warning: method redefined;

array.c

@@ -5652,16 +5652,22 @@ rb_ary_dig(int argc, VALUE *argv, VALUE self)
 
 /*
  * call-seq:
- *   ary.sum                 -> number
+ *   ary.sum(init=0)                    -> number
+ *   ary.sum(init=0) {|e| expr }        -> number
  *
  * Returns the sum of elements.
- * For example, [e1, e2, e3].sum returns 0 + e1 + e2 + e3.
+ * For example, [e1, e2, e3].sum returns init + e1 + e2 + e3.
  *
- * If <i>ary</i> is empty, it returns 0.
+ * If a block is given, the block is applied to each element
+ * before addtion.
+ *
+ * If <i>ary</i> is empty, it returns <i>init</i>.
  *
  *   [].sum                             #=> 0
+ *   [].sum(0.0)                        #=> 0.0
  *   [1, 2, 3].sum                      #=> 6
  *   [3, 5.5].sum                       #=> 8.5
+ *   [2.5, 3.0].sum(0.0) {|v| v * v }   #=> 15.25
  *   [Object.new].sum                   #=> TypeError
  *
  * This method may not respect method redefinition of "+" methods
@@ -5669,20 +5675,26 @@ rb_ary_dig(int argc, VALUE *argv, VALUE self)
  *
  */
 
-VALUE
+static VALUE
-rb_ary_sum(VALUE ary)
+rb_ary_sum(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE v, e;
+    VALUE e, v;
     long i, n;
+    int block_given;
+
+    if (rb_scan_args(argc, argv, "01", &v) == 0)
+        v = LONG2FIX(0);
+
+    block_given = rb_block_given_p();
 
     if (RARRAY_LEN(ary) == 0)
-        return LONG2FIX(0);
+        return v;
-
-    v = LONG2FIX(0);
 
     n = 0;
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         e = RARRAY_AREF(ary, i);
+        if (block_given)
+            e = rb_yield(e);
         if (FIXNUM_P(e)) {
             n += FIX2LONG(e); /* should not overflow long type */
             if (!FIXABLE(n)) {
@@ -5711,6 +5723,8 @@ rb_ary_sum(VALUE ary)
         for (; i < RARRAY_LEN(ary); i++) {
             double x, y, t;
             e = RARRAY_AREF(ary, i);
+            if (block_given)
+                e = rb_yield(e);
             if (RB_FLOAT_TYPE_P(e))
                 x = RFLOAT_VALUE(e);
             else if (FIXNUM_P(e))
@@ -5732,7 +5746,10 @@ rb_ary_sum(VALUE ary)
     }
 
     for (; i < RARRAY_LEN(ary); i++) {
-        v = rb_funcall(v, idPLUS, 1, RARRAY_AREF(ary, i));
+        e = RARRAY_AREF(ary, i);
+        if (block_given)
+            e = rb_yield(e);
+        v = rb_funcall(v, idPLUS, 1, e);
     }
     return v;
 }
@@ -6092,7 +6109,7 @@ Init_Array(void)
     rb_define_method(rb_cArray, "bsearch_index", rb_ary_bsearch_index, 0);
     rb_define_method(rb_cArray, "any?", rb_ary_any_p, 0);
     rb_define_method(rb_cArray, "dig", rb_ary_dig, -1);
-    rb_define_method(rb_cArray, "sum", rb_ary_sum, 0);
+    rb_define_method(rb_cArray, "sum", rb_ary_sum, -1);
 
     id_cmp = rb_intern("<=>");
     id_random = rb_intern("random");

test/ruby/test_array.rb

@@ -2714,34 +2714,42 @@ class TestArray < Test::Unit::TestCase
   FIXNUM_MIN = -(1 << (8 * RbConfig::SIZEOF['long'] - 2))
   FIXNUM_MAX = (1 << (8 * RbConfig::SIZEOF['long'] - 2)) - 1
 
+  def assert_int_equal(e, v, msg=nil)
+    assert_kind_of(Integer, v, msg)
+    assert_equal(e, v, msg)
+  end
+
   def assert_float_equal(e, v, msg=nil)
     assert_equal(Float, v.class, msg)
     assert_equal(e, v, msg)
   end
 
   def test_sum
-    assert_equal(0, [].sum)
+    assert_int_equal(0, [].sum)
-    assert_equal(3, [3].sum)
+    assert_float_equal(0.0, [].sum(0.0))
-    assert_equal(8, [3, 5].sum)
+    assert_int_equal(3, [3].sum)
-    assert_equal(15, [3, 5, 7].sum)
+    assert_int_equal(8, [3, 5].sum)
+    assert_int_equal(15, [3, 5, 7].sum)
     assert_float_equal(15.0, [3, 5, 7.0].sum)
-    assert_equal(2*FIXNUM_MAX, Array.new(2, FIXNUM_MAX).sum)
+    assert_int_equal(2*FIXNUM_MAX, Array.new(2, FIXNUM_MAX).sum)
-    assert_equal(2*(FIXNUM_MAX+1), Array.new(2, FIXNUM_MAX+1).sum)
+    assert_int_equal(2*(FIXNUM_MAX+1), Array.new(2, FIXNUM_MAX+1).sum)
-    assert_equal(10*FIXNUM_MAX, Array.new(10, FIXNUM_MAX).sum)
+    assert_int_equal(10*FIXNUM_MAX, Array.new(10, FIXNUM_MAX).sum)
-    assert_equal(0, ([FIXNUM_MAX, 1, -FIXNUM_MAX, -1]*10).sum)
+    assert_int_equal(0, ([FIXNUM_MAX, 1, -FIXNUM_MAX, -1]*10).sum)
-    assert_equal(FIXNUM_MAX*10, ([FIXNUM_MAX+1, -1]*10).sum)
+    assert_int_equal(FIXNUM_MAX*10, ([FIXNUM_MAX+1, -1]*10).sum)
-    assert_equal(2*FIXNUM_MIN, Array.new(2, FIXNUM_MIN).sum)
+    assert_int_equal(2*FIXNUM_MIN, Array.new(2, FIXNUM_MIN).sum)
-    assert_equal((FIXNUM_MAX+1).to_f, [FIXNUM_MAX, 1, 0.0].sum)
+    assert_float_equal((FIXNUM_MAX+1).to_f, [FIXNUM_MAX, 1, 0.0].sum)
     assert_float_equal(8.0, [3.0, 5].sum)
     assert_float_equal((FIXNUM_MAX+1).to_f, [0.0, FIXNUM_MAX+1].sum)
     assert_equal(2.0+3.0i, [2.0, 3.0i].sum)
+    assert_int_equal(13, [1, 2].sum(10))
+    assert_int_equal(16, [1, 2].sum(10) {|v| v * 2 })
 
     large_number = 100000000
     small_number = 1e-9
     until (large_number + small_number) == large_number
       small_number /= 10
     end
-    assert_equal(large_number+(small_number*10), [large_number, *[small_number]*10].sum)
+    assert_float_equal(large_number+(small_number*10), [large_number, *[small_number]*10].sum)
   end
 
   private