怎么改写

	reg test[3:0];			
always @(posedge clk) begin
    //int i=0;
    if(rst) begin
        test[0] <=0;
        test[1] <=0;
        test[2] <=0;
        test[3] <=0;
    end
    else begin
            if(test[0]==0) begin
                if(wea )
                    test[0] <= 1;
            end
            else if(test[1]==0) begin //优先级
                if(wea )
                    test[1] <= 1;
            end
            else if(test[2]==0) begin
                if(wea )
                    test[2] <= 1;
            end
            else if(test[3]==0) begin
                if(wea )
                    test[3] <= 1;
            end
     end
    
end		

实现

reg test[3:0];			
always @(posedge clk) 
    if(rst)
      test = '{default:0};
    else 
      foreach(test[i])
        if(test[i]==0) begin
          if(wea )
            test[0] <= 1;
          break;
        end