17. Binary to Gray Code Converter

How do you plan to solve it?

module bin2gray4(
    input [3:0]bin_in,
    output [3:0]gray_out
);
assign gray_out[3] = bin_in[3];
xor(gray_out[2],bin_in[3],bin_in[2]);
xor(gray_out[1],bin_in[2],bin_in[1]);
xor(gray_out[0],bin_in[1],bin_in[0]);
endmodule