17. Binary to Gray Code Converter

How do you plan to solve it?

/*Write your code here*/
module bin2gray4
(
    input wire [3:0] bin_in,
    output reg [3:0] gray_out
);
integer i;
always@*
begin
    gray_out[3]=bin_in[3];
    for(i=2;i>=0;i=i-1)
        gray_out[i]=bin_in[i+1]^bin_in[i];
end
endmodule