with sql_exceptions;

package body sql_double_precision_pkg is
   
   null_value_error : exception renames sql_exceptions. null_value_error;
   
   function without_null_base (value : sql_double_precision) return sql_double_precision_not_null is
   begin 
      if value. is_null then
         raise null_value_error;
      else
         return value. value;
      end if;
   end without_null_base;
   
   
   function with_null_base (value : sql_double_precision_not_null) return sql_double_precision is
   begin 
      return (false, value);
   end with_null_base;
   
   
   procedure assign_with_check 
      (left : in out sql_double_precision; 
       right : sql_double_precision; 
       first, last : sql_double_precision_not_null) 
   is
   begin 
      if right. is_null then
         left. is_null := true;
      elsif (right. value < first or else right. value > last) then
         raise constraint_error;
      else
         left := right;
      end if;
   end assign_with_check;
   
   
   function null_sql_double_precision return sql_double_precision is
      null_holder : sql_double_precision; 
   begin 
      return (null_holder); -- relies on default expression for is_null
   end null_sql_double_precision;
   
   
   function "+" (right : sql_double_precision) return sql_double_precision is
   begin 
      return right;
   end "+";
   
   
   function "-" (right : sql_double_precision) return sql_double_precision is
   begin 
      return (right. is_null, - (right. value));
   end "-";
   
   
   function "abs" (right : sql_double_precision) return sql_double_precision is
   begin 
      return (right. is_null, abs (right. value));
   end "abs";
   
   
   function "+" (left, right : sql_double_precision) return sql_double_precision is
   begin 
      if left. is_null or right. is_null then
         return null_sql_double_precision;
      else
         return (false, (left. value + right. value));
      end if;
   end "+";
   
   
   function "*" (left, right : sql_double_precision) return sql_double_precision is
   begin 
      if left. is_null or right. is_null then
         return null_sql_double_precision;
      else
         return (false, (left. value * right. value));
      end if;
   end "*";
   
   
   function "-" (left, right : sql_double_precision) return sql_double_precision is
   begin 
      if left. is_null or right. is_null then
         return null_sql_double_precision;
      else
         return (false, (left. value - right. value));
      end if;
   end "-";
   
   
   function "/" (left, right : sql_double_precision) return sql_double_precision is
   begin 
      if left. is_null or right. is_null then
         return null_sql_double_precision;
      else
         return (false, (left. value / right. value));
      end if;
   end "/";
   
   
    function "**" 
      (left : sql_double_precision; 
       right : integer) 
      return sql_double_precision 
   is
   begin 
      if left. is_null then
         return null_sql_double_precision;
      else
         return (false, (left. value ** right));
      end if;
   end "**";
   
      function equals (left, right : sql_double_precision) return boolean_with_unknown is
   begin 
      if left. is_null or right. is_null then
         return unknown;
      elsif left. value = right. value then
         return true;
      else
         return false;
      end if;
   end equals;
   
   
   function not_equals (left, right : sql_double_precision) return boolean_with_unknown is
   begin 
      if left. is_null or right. is_null then
         return unknown;
      elsif left. value = right. value then
         return false;
      else
         return true;
      end if;
   end not_equals;
   
   
   function "<" (left, right : sql_double_precision) return boolean_with_unknown is
   begin 
      if left. is_null or right. is_null then
         return unknown;
      elsif left. value < right. value then
         return true;
      else
         return false;
      end if;
   end "<";
   
   
   function ">" (left, right : sql_double_precision) return boolean_with_unknown is
   begin 
      if left. is_null or right. is_null then
         return unknown;
      elsif left. value > right. value then
         return true;
      else
         return false;
      end if;
   end ">";
   
   
   function "<=" (left, right : sql_double_precision) return boolean_with_unknown is
   begin 
      if left. is_null or right. is_null then
         return unknown;
      elsif left. value <= right. value then
         return true;
      else
         return false;
      end if;
   end "<=";
   
   
   function ">=" (left, right : sql_double_precision) return boolean_with_unknown is
   begin 
      if left. is_null or right. is_null then
         return unknown;
      elsif left. value >= right. value then
         return true;
      else
         return false;
      end if;
   end ">=";
   
   
   function is_null (value : sql_double_precision) return boolean is
   begin 
      return value. is_null;
   end;
   
   
   function not_null (value : sql_double_precision) return boolean is
   begin 
      return not value. is_null;
   end;
   
   
   function "=" (left, right : sql_double_precision) return boolean is
   begin 
      if left. is_null or else right. is_null then
         return false;
      else
         return left. value = right. value;
      end if;
   end "=";
   
   
   function "<" (left, right : sql_double_precision) return boolean is
   begin 
      if left. is_null or else right. is_null then
         return false;
      else
         return left. value < right. value;
      end if;
   end "<";
   
   
   function ">" (left, right : sql_double_precision) return boolean is
   begin 
      if left. is_null or else right. is_null then
         return false;
      else
         return left. value > right. value;
      end if;
   end ">";
   
   
   function "<=" (left, right : sql_double_precision) return boolean is
   begin 
      if left. is_null or else right. is_null then
         return false;
      else
         return left. value <= right. value;
      end if;
   end "<=";
   
   
   function ">=" (left, right : sql_double_precision) return boolean is
   begin 
      if left. is_null or else right. is_null then
         return false;
      else
         return left. value >= right. value;
      end if;
   end ">=";
   
   
   package body sql_double_precision_ops is
      
      
      function with_null (value : without_null_type) return with_null_type is
      begin 
         return (with_null_base (sql_double_precision_not_null (value)));
      end with_null;
      
      
      function without_null (value : with_null_type) return without_null_type 
      is
      begin 
         return 
            (without_null_type (sql_double_precision_not_null'(without_null_base (value))));
      end without_null;
      
      
      procedure assign 
         (left : in out with_null_type; 
          right : in with_null_type) 
      is
      begin 
         assign_with_check 
            (left, right, 
             sql_double_precision_not_null (without_null_type'first), 
             sql_double_precision_not_null (without_null_type'last));
      end assign;
      
    
   end;
   
 
end;