Derive SimpleTypedList from Array

Currently the SimpleTypedList is wrapping `@list` Array and re-implementing
certain methods to add type / value checking and delegating all the
non-destrutive methods to the internal @list.

Most everything that ends up being serialized to the excel file is derived
from SimpleTypedList (for example, a Row is a SimpleTypedList of Cells). This
means that many of the delegated methods are hit over and over again especially
`[]`. This extra delegation really adds up.

We can avoid the delegation by having SimpleTypedList extend Array and still
remove any un-safe methods.

It is possible to re-introduce an unsafe method in a subclass of SimpleTypedList
if needed. Here is one way,
```ruby
class MyList < SimpleTypedList
  def clear
    @clear_method ||= Array.instance_method(:clear).bind(self)
    @clear_method.call
  end
end
```

1 files changed, 23 insertions, 0 deletions

diff --git a/test/util/tc_simple_typed_list.rb b/test/util/tc_simple_typed_list.rb
index ac65529d..b62b5353 100644
--- a/test/util/tc_simple_typed_list.rb
+++ b/test/util/tc_simple_typed_list.rb
@@ -58,6 +58,9 @@ class TestSimpleTypedList < Test::Unit::TestCase
     assert_raise(ArgumentError) { @list.delete 1  }
     assert_raise(ArgumentError) { @list.delete_at 1 }
     assert_raise(ArgumentError) { @list.delete_at 2 }
+    assert_raise(ArgumentError) { @list.insert(1, 3) }
+    assert_raise(ArgumentError) { @list[1] = 3 }
+
     @list.push 4
     assert_nothing_raised { @list.delete_at 3 }
     @list.unlock
@@ -81,4 +84,24 @@ class TestSimpleTypedList < Test::Unit::TestCase
 
     assert_equal([1, 2], @list.to_ary)
   end
+
+  def test_insert
+    assert_raise(ArgumentError) { @list << nil }
+
+    assert_equal(1, @list.insert(0, 1))
+    assert_equal(2, @list.insert(1, 2))
+    assert_equal(3, @list.insert(0, 3))
+
+    assert_equal([3, 1, 2], @list)
+  end
+
+  def test_setter
+    assert_raise(ArgumentError) { @list[0] = nil }
+
+    assert_equal(1, @list[0] = 1)
+    assert_equal(2, @list[1] = 2)
+    assert_equal(3, @list[0] = 3)
+
+    assert_equal([3, 2], @list)
+  end
 end