Fix Vector initialization when dtype is nmatrix, vector has nils and …

…no nm_type is given (#153) (#369)

lib/daru/accessors/nmatrix_wrapper.rb

@@ -25,6 +25,8 @@ def inject(*args, &block)
         attr_reader :size, :data, :nm_dtype
 
         def initialize vector, context, nm_dtype=:int32
+          # To avoid arrays with nils throwing TypeError for nil nm_dtype
+          nm_dtype = :object if nm_dtype.nil? && vector.any?(&:nil?)
           @size = vector.size
           @data = NMatrix.new [@size*2], vector.to_a, dtype: nm_dtype
           @context = context

lib/daru/vector.rb

@@ -1515,7 +1515,7 @@ def cast_vector_to dtype, source=nil, nm_dtype=nil
         else raise ArgumentError, "Unknown dtype #{dtype}"
         end
 
-      @dtype = dtype || :array
+      @dtype = dtype
       new_vector
     end
 

spec/vector_spec.rb

@@ -84,6 +84,11 @@
           expect(dv.index.to_a).to eq(['a', 'b', :r, 0])
         end
 
+        it "initializes array with nils with dtype NMatrix" do
+          dv = Daru::Vector.new [2, nil], dtype: :nmatrix
+          expect(dv.to_a).to eq([2, nil])
+          expect(dv.index.to_a).to eq([0, 1])
+        end
       end
 
       context "#reorder!" do