array.c: integer calculations

* array.c (rb_ary_cycle_size, descending_factorial): use
  rb_int_mul instead of rb_funcallv.

* array.c (binomial_coefficient): use rb_int_idiv instead of
  rb_funcallv.

* array.c (rb_ary_repeated_permutation_size): use
  rb_int_positive_pow.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59689 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

array.c

@@ -25,8 +25,6 @@
 
 VALUE rb_cArray;
 
-static ID id_div;
-
 /* for OPTIMIZED_CMP: */
 #define id_cmp idCmp
 
@@ -4955,7 +4953,7 @@ rb_ary_cycle_size(VALUE self, VALUE args, VALUE eobj)
     mul = NUM2LONG(n);
     if (mul <= 0) return INT2FIX(0);
     n = LONG2FIX(mul);
-    return rb_funcallv(rb_ary_length(self), '*', 1, &n);
+    return rb_fix_mul_fix(rb_ary_length(self), n);
 }
 
 /*
@@ -5084,7 +5082,7 @@ descending_factorial(long from, long how_many)
     VALUE cnt = LONG2FIX(how_many >= 0);
     while (how_many-- > 0) {
 	VALUE v = LONG2FIX(from--);
-	cnt = rb_funcallv(cnt, '*', 1, &v);
+	cnt = rb_int_mul(cnt, v);
     }
     return cnt;
 }
@@ -5101,7 +5099,7 @@ binomial_coefficient(long comb, long size)
     }
     r = descending_factorial(size, comb);
     v = descending_factorial(comb, comb);
-    return rb_funcallv(r, id_div, 1, &v);
+    return rb_int_idiv(r, v);
 }
 
 static VALUE
@@ -5306,14 +5304,14 @@ rb_ary_repeated_permutation_size(VALUE ary, VALUE args, VALUE eobj)
 {
     long n = RARRAY_LEN(ary);
     long k = NUM2LONG(RARRAY_AREF(args, 0));
-    VALUE v;
 
     if (k < 0) {
 	return LONG2FIX(0);
     }
-
-    v = LONG2NUM(k);
-    return rb_funcallv(LONG2NUM(n), idPow, 1, &v);
+    if (n <= 0) {
+	return LONG2FIX(!k);
+    }
+    return rb_int_positive_pow(n, (unsigned long)k);
 }
 
 /*
@@ -6263,5 +6261,4 @@ Init_Array(void)
     rb_define_method(rb_cArray, "sum", rb_ary_sum, -1);
 
     id_random = rb_intern("random");
-    id_div = rb_intern("div");
 }

test/ruby/test_array.rb

@@ -1838,12 +1838,22 @@ class TestArray < Test::Unit::TestCase
   end
 
   def test_combination
-    assert_equal(@cls[[]], @cls[1,2,3,4].combination(0).to_a)
-    assert_equal(@cls[[1],[2],[3],[4]], @cls[1,2,3,4].combination(1).to_a)
-    assert_equal(@cls[[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]], @cls[1,2,3,4].combination(2).to_a)
-    assert_equal(@cls[[1,2,3],[1,2,4],[1,3,4],[2,3,4]], @cls[1,2,3,4].combination(3).to_a)
-    assert_equal(@cls[[1,2,3,4]], @cls[1,2,3,4].combination(4).to_a)
-    assert_equal(@cls[], @cls[1,2,3,4].combination(5).to_a)
+    a = @cls[]
+    assert_equal(1, a.combination(0).size)
+    assert_equal(0, a.combination(1).size)
+    a = @cls[1,2,3,4]
+    assert_equal(1, a.combination(0).size)
+    assert_equal(4, a.combination(1).size)
+    assert_equal(6, a.combination(2).size)
+    assert_equal(4, a.combination(3).size)
+    assert_equal(1, a.combination(4).size)
+    assert_equal(0, a.combination(5).size)
+    assert_equal(@cls[[]], a.combination(0).to_a)
+    assert_equal(@cls[[1],[2],[3],[4]], a.combination(1).to_a)
+    assert_equal(@cls[[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]], a.combination(2).to_a)
+    assert_equal(@cls[[1,2,3],[1,2,4],[1,3,4],[2,3,4]], a.combination(3).to_a)
+    assert_equal(@cls[[1,2,3,4]], a.combination(4).to_a)
+    assert_equal(@cls[], a.combination(5).to_a)
   end
 
   def test_product
@@ -1875,7 +1885,16 @@ class TestArray < Test::Unit::TestCase
   end
 
   def test_permutation
+    a = @cls[]
+    assert_equal(1, a.permutation(0).size)
+    assert_equal(0, a.permutation(1).size)
     a = @cls[1,2,3]
+    assert_equal(1, a.permutation(0).size)
+    assert_equal(3, a.permutation(1).size)
+    assert_equal(6, a.permutation(2).size)
+    assert_equal(6, a.permutation(3).size)
+    assert_equal(0, a.permutation(4).size)
+    assert_equal(6, a.permutation.size)
     assert_equal(@cls[[]], a.permutation(0).to_a)
     assert_equal(@cls[[1],[2],[3]], a.permutation(1).to_a.sort)
     assert_equal(@cls[[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]],
@@ -1910,7 +1929,14 @@ class TestArray < Test::Unit::TestCase
   end
 
   def test_repeated_permutation
+    a = @cls[]
+    assert_equal(1, a.repeated_permutation(0).size)
+    assert_equal(0, a.repeated_permutation(1).size)
     a = @cls[1,2]
+    assert_equal(1, a.repeated_permutation(0).size)
+    assert_equal(2, a.repeated_permutation(1).size)
+    assert_equal(4, a.repeated_permutation(2).size)
+    assert_equal(8, a.repeated_permutation(3).size)
     assert_equal(@cls[[]], a.repeated_permutation(0).to_a)
     assert_equal(@cls[[1],[2]], a.repeated_permutation(1).to_a.sort)
     assert_equal(@cls[[1,1],[1,2],[2,1],[2,2]],
@@ -1944,7 +1970,15 @@ class TestArray < Test::Unit::TestCase
   end
 
   def test_repeated_combination
+    a = @cls[]
+    assert_equal(1, a.repeated_combination(0).size)
+    assert_equal(0, a.repeated_combination(1).size)
     a = @cls[1,2,3]
+    assert_equal(1, a.repeated_combination(0).size)
+    assert_equal(3, a.repeated_combination(1).size)
+    assert_equal(6, a.repeated_combination(2).size)
+    assert_equal(10, a.repeated_combination(3).size)
+    assert_equal(15, a.repeated_combination(4).size)
     assert_equal(@cls[[]], a.repeated_combination(0).to_a)
     assert_equal(@cls[[1],[2],[3]], a.repeated_combination(1).to_a.sort)
     assert_equal(@cls[[1,1],[1,2],[1,3],[2,2],[2,3],[3,3]],
@@ -2495,6 +2529,9 @@ class TestArray < Test::Unit::TestCase
     a = []
     [0, 1, 2].cycle(3) {|i| a << i }
     assert_equal([0, 1, 2, 0, 1, 2, 0, 1, 2], a)
+
+    assert_equal(Float::INFINITY, a.cycle.size)
+    assert_equal(27, a.cycle(3).size)
   end
 
   def test_reverse_each2