17. Binary to Gray Code Converter

How do you plan to solve it?

module bin2gray4(
    input [3:0]bin_in,
    output reg [3:0]gray_out
);

//assign gray_out = bin_in ^ bin_in>>1;

integer i;

always@(*) begin
    for(i=2; i>=0; i = i-1) begin
        gray_out[i] <= bin_in[i] ^ bin_in[i+1];
    end
    gray_out[3] <= bin_in[3];
end

endmodule