Re: APQ

[Brian May <bam@snoopy.apana.org.au>]

[-- Attachment #1: Type: text/plain, Size: 891 bytes --]

>>>>> "Brian" == Brian May <bam@snoopy.apana.org.au> writes:

    Brian> Good point. I meant to change it in both places, but I think I ended
    Brian> up changing it in only one place...

You were right, I missed it up.

Here is a patch that turns all methods into abstract methods.

Unfortunately, I could not make Finalize abstract, the compiler
complained that abstract methods must be visible (Finalize is in the
private section). This restriction seems strange to me, but I am not
going to argue with the compiler and left the function generating an
exception at run-time.

I suspect Finalize doesn't need to be abstract, but didn't go
exploring enough to verify why it is abstract.

Also, I noticed that the pointers are "access all". I couldn't see any
requirement for "all", and my code still compiles, so I changed them
to "access". This eliminates a potential source of errors.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: patch for abstract methods --]
[-- Type: text/x-patch, Size: 13506 bytes --]

--- apq-2.1-old/apq.ads	2003-09-25 05:56:24.000000000 +1000
+++ apq-2.1/apq.ads	2004-12-18 09:50:31.000000000 +1100
@@ -90,7 +90,7 @@
 
    type Column_Index_Type is new Positive;
 
-   type Root_Connection_Type is new Ada.Finalization.Limited_Controlled with private;
+   type Root_Connection_Type is abstract new Ada.Finalization.Limited_Controlled with private;
 
    type Trace_Mode_Type is (
       Trace_None,                      -- No tracing
@@ -101,10 +101,10 @@
 
    type Fetch_Mode_Type is ( Sequential_Fetch, Random_Fetch );
 
-   type Root_Query_Type is new Ada.Finalization.Controlled with private;
+   type Root_Query_Type is abstract new Ada.Finalization.Controlled with private;
 
 
-   function Engine_Of(C : Root_Connection_Type) return Database_Type;
+   function Engine_Of(C : Root_Connection_Type) return Database_Type is Abstract;
    function New_Query(C : Root_Connection_Type) return Root_Query_Type'Class;
 
    procedure Set_Host_Name(C : in out Root_Connection_Type; Host_Name : String);
@@ -123,13 +123,13 @@
    function User(C : Root_Connection_Type) return String;
    function Password(C : Root_Connection_Type) return String;
 
-   procedure Connect(C : in out Root_Connection_Type);   -- IS ABSTRACT
-   procedure Connect(C : in out Root_Connection_Type; Same_As : Root_Connection_Type'Class); -- IS ABSTRACT
-   procedure Disconnect(C : in out Root_Connection_Type); -- IS ABSTRACT
-
-   function Is_Connected(C : Root_Connection_Type) return Boolean; -- IS ABSTRACT
-   procedure Reset(C : in out Root_Connection_Type); -- IS ABSTRACT
-   function Error_Message(C : Root_Connection_Type) return String; -- IS ABSTRACT
+   procedure Connect(C : in out Root_Connection_Type) is abstract;
+   procedure Connect(C : in out Root_Connection_Type; Same_As : Root_Connection_Type'Class) is abstract;
+   procedure Disconnect(C : in out Root_Connection_Type) is abstract;
+
+   function Is_Connected(C : Root_Connection_Type) return Boolean is abstract;
+   procedure Reset(C : in out Root_Connection_Type) is abstract;
+   function Error_Message(C : Root_Connection_Type) return String is abstract;
 
    function In_Abort_State(C : Root_Connection_Type) return Boolean;
 
@@ -137,7 +137,7 @@
    function Will_Rollback_On_Finalize(C : Root_Connection_Type) return Boolean;
 
 
-   function Engine_Of(Q : Root_Query_Type) return Database_Type;
+   function Engine_Of(Q : Root_Query_Type) return Database_Type is Abstract;
 
    procedure Clear(Q : in out Root_Query_Type);
    function Fetch_Mode(Q : Root_Query_Type) return Fetch_Mode_Type;
@@ -160,40 +160,40 @@
    procedure Append_Quoted(Q : in out Root_Query_Type; Connection : Root_Connection_Type'Class; SQL : String; After : String := "");
    procedure Append_Quoted(Q : in out Root_Query_Type; Connection : Root_Connection_Type'Class; SQL : Ada.Strings.Unbounded.Unbounded_String; After : String := "");
 
-   procedure Execute(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class);
-   procedure Execute_Checked(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class; Msg : String := "");
+   procedure Execute(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is abstract;
+   procedure Execute_Checked(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class; Msg : String := "") is abstract;
 
-   procedure Begin_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class);
-   procedure Commit_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class);
-   procedure Rollback_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class);
+   procedure Begin_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is abstract;
+   procedure Commit_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is abstract;
+   procedure Rollback_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is abstract;
 
    procedure Raise_Exceptions(Query : in out Root_Query_Type; Raise_On : Boolean := True);
    procedure Report_Errors(Query : in out Root_Query_Type; Report_On : Boolean := True);
    
-   procedure Rewind(Q : in out Root_Query_Type);
-   procedure Fetch(Q : in out Root_Query_Type);
-   procedure Fetch(Q : in out Root_Query_Type; TX : Tuple_Index_Type);
-
-   function End_of_Query(Q : Root_Query_Type) return Boolean;
-   function Tuple(Q : Root_Query_Type) return Tuple_Index_Type;
-   function Tuples(Q : Root_Query_Type) return Tuple_Count_Type;
+   procedure Rewind(Q : in out Root_Query_Type) is abstract;
+   procedure Fetch(Q : in out Root_Query_Type) is abstract;
+   procedure Fetch(Q : in out Root_Query_Type; TX : Tuple_Index_Type) is abstract;
+
+   function End_of_Query(Q : Root_Query_Type) return Boolean is abstract;
+   function Tuple(Q : Root_Query_Type) return Tuple_Index_Type is abstract;
+   function Tuples(Q : Root_Query_Type) return Tuple_Count_Type is abstract;
 
-   function Value(Query : Root_Query_Type; CX : Column_Index_Type) return String;     -- Abstract
+   function Value(Query : Root_Query_Type; CX : Column_Index_Type) return String is abstract;
 
    procedure Value(Query: Root_Query_Type; CX : Column_Index_Type; V : out String);
    function Value(Query : Root_Query_Type; CX : Column_Index_Type) return Ada.Strings.Unbounded.Unbounded_String;
    function Value(Query : Root_Query_Type; CX : Column_Index_Type) return Row_ID_Type;
    function Value(Query : Root_Query_Type; CX : Column_Index_Type) return APQ_Bitstring;
 
-   function Result(Query : Root_Query_Type) return Natural;    -- Returns Result_Type'Pos()
+   function Result(Query : Root_Query_Type) return Natural is abstract;    -- Returns Result_Type'Pos()
 
-   function Is_Null(Q : Root_Query_Type; CX : Column_Index_Type) return Boolean;
+   function Is_Null(Q : Root_Query_Type; CX : Column_Index_Type) return Boolean is abstract;
 
-   function Command_Oid(Query : Root_Query_Type) return Row_ID_Type;
-   function Null_Oid(Query : Root_Query_Type) return Row_ID_Type;
+   function Command_Oid(Query : Root_Query_Type) return Row_ID_Type is abstract;
+   function Null_Oid(Query : Root_Query_Type) return Row_ID_Type is abstract;
 
-   function Error_Message(Query : Root_Query_Type) return String;
-   function Is_Duplicate_Key(Query : Root_Query_Type) return Boolean;
+   function Error_Message(Query : Root_Query_Type) return String is abstract;
+   function Is_Duplicate_Key(Query : Root_Query_Type) return Boolean is abstract;
    function To_String(Query : Root_Query_Type) return String;
 
 
@@ -573,15 +573,15 @@
 
    package CStr renames Interfaces.C_Streams;
 
-   type String_Ptr is access all String;
+   type String_Ptr is access String;
    type String_Ptr_Array is array(Natural range <>) of String_Ptr;
-   type String_Ptr_Array_Access is access all String_Ptr_Array;
-   type Stream_Element_Array_Ptr is access all Ada.Streams.Stream_Element_Array;
+   type String_Ptr_Array_Access is access String_Ptr_Array;
+   type Stream_Element_Array_Ptr is access Ada.Streams.Stream_Element_Array;
 
    subtype Port_Integer is Integer range 0..32768;
    type Port_Format_Type is ( IP_Port, UNIX_Port );
 
-   type Root_Connection_Type is new Ada.Finalization.Limited_Controlled with
+   type Root_Connection_Type is abstract new Ada.Finalization.Limited_Controlled with
       record
          Host_Name :       String_Ptr;                      -- Host name string or..
          Host_Address :    String_Ptr;                      -- Host IP address
@@ -602,7 +602,7 @@
 
    procedure Clear_Abort_State(C : in out Root_Connection_Type);
 
-   type Root_Query_Type is new Ada.Finalization.Controlled with
+   type Root_Query_Type is abstract new Ada.Finalization.Controlled with
       record
          Count :           Natural := 0;              -- # of elements in the Collection
          Alloc :           Natural := 0;              -- # of allocated elements in the Collection
--- apq-2.1-old/apq.adb	2003-09-25 05:56:24.000000000 +1000
+++ apq-2.1/apq.adb	2004-12-18 09:10:51.000000000 +1100
@@ -198,38 +198,6 @@
 
    -- ABSTRACT PRIMITIVES
 
-   procedure Connect(C : in out Root_Connection_Type) is
-   begin
-      raise Is_Abstract;
-   end Connect;
-
-   procedure Connect(C : in out Root_Connection_Type; Same_As : Root_Connection_Type'Class) is
-   begin
-      raise Is_Abstract;
-   end Connect;
-   
-   procedure Disconnect(C : in out Root_Connection_Type) is
-   begin
-      raise Is_Abstract;
-   end Disconnect;
-
-   function Is_Connected(C : Root_Connection_Type) return Boolean is
-   begin
-      raise Is_Abstract;
-      return False;
-   end Is_Connected;
-   
-   procedure Reset(C : in out Root_Connection_Type) is
-   begin
-      raise Is_Abstract;
-   end Reset;
-   
-   function Error_Message(C : Root_Connection_Type) return String is
-   begin
-      raise Is_Abstract;
-      return "";
-   end Error_Message;
-
    procedure Clear(Q : in out Root_Query_Type) is
    begin
       for X in 1..Q.Count loop
@@ -368,45 +336,6 @@
       end;
    end To_String;
 
-   procedure Rewind(Q : in out Root_Query_Type) is
-   begin
-      raise Is_Abstract;
-   end Rewind;
-
-   procedure Fetch(Q : in out Root_Query_Type) is
-   begin
-      raise Is_Abstract;
-   end Fetch;
-
-   procedure Fetch(Q : in out Root_Query_Type; TX : Tuple_Index_Type) is
-   begin
-      raise Is_Abstract;
-   end Fetch;
-
-   function End_of_Query(Q : Root_Query_Type) return Boolean is
-   begin
-      raise Is_Abstract;
-      return False;
-   end End_of_Query;
-
-   function Tuple(Q : Root_Query_Type) return Tuple_Index_Type is
-   begin
-      raise Is_Abstract;
-      return Tuple_Index_Type'First;
-   end Tuple;
-
-   function Tuples(Q : Root_Query_Type) return Tuple_Count_Type is
-   begin
-      raise Is_Abstract;
-      return Tuple_Count_Type'First;
-   end Tuples;
-
-   function Value(Query : Root_Query_Type; CX : Column_Index_Type) return String is
-   begin
-      raise Is_Abstract;
-      return ":-)";
-   end Value;
-
    function Value(Query : Root_Query_Type; CX : Column_Index_Type) return Ada.Strings.Unbounded.Unbounded_String is
       use Ada.Strings.Unbounded;
    begin
@@ -443,73 +372,6 @@
       return C.Rollback_Finalize;
    end Will_Rollback_On_Finalize;
 
-   function Result(Query : Root_Query_Type) return Natural is
-   begin
-      raise Is_Abstract;         -- This primitive must be overridden by the implementation
-      return 0;                  -- This is just to satisfy the compiler (not executed)
-   end Result;
-
-   function Engine_Of(C : Root_Connection_Type) return Database_Type is
-   begin
-      raise Is_Abstract;            -- Must be overridden
-      return Database_Type'First;   -- To quiet the compiler
-   end Engine_Of;
-
-   function Engine_Of(Q : Root_Query_Type) return Database_Type is
-   begin
-      raise Is_Abstract;            -- Must be overridden
-      return Database_Type'First;   -- To quiet the compiler
-   end Engine_Of;
-
-   function Command_Oid(Query : Root_Query_Type) return Row_ID_Type is
-   begin
-      raise Is_Abstract;
-      return Row_ID_Type'First;
-   end Command_Oid;
-
-   function Null_Oid(Query : Root_Query_Type) return Row_ID_Type is
-   begin
-      raise Is_Abstract;
-      return Row_ID_Type'First;
-   end Null_Oid;
-
-   function Error_Message(Query : Root_Query_Type) return String is
-   begin
-      raise Is_Abstract;
-      return "";
-   end Error_Message;
-
-   function Is_Duplicate_Key(Query : Root_Query_Type) return Boolean is
-   begin
-      raise Is_Abstract;
-      return False;
-   end Is_Duplicate_Key;
-
-   procedure Execute(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is
-   begin
-      raise Is_Abstract;
-   end Execute;
-
-   procedure Execute_Checked(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class; Msg : String := "") is
-   begin
-      raise Is_Abstract;
-   end Execute_Checked;
-
-   procedure Begin_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is
-   begin
-      raise Is_Abstract;
-   end Begin_Work;
-
-   procedure Commit_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is
-   begin
-      raise Is_Abstract;
-   end Commit_Work;
-
-   procedure Rollback_Work(Query : in out Root_Query_Type; Connection : in out Root_Connection_Type'Class) is
-   begin
-      raise Is_Abstract;
-   end Rollback_Work;
-
    function Time_Component(TM : Ada.Calendar.Day_Duration; Unit : Time_Unit) return Natural is
    begin
       case Unit is
@@ -1178,12 +1040,6 @@
       end if;
    end Encode_Bitstring;
 
-   function Is_Null(Q : Root_Query_Type; CX : Column_Index_Type) return Boolean is
-   begin
-      raise Is_Abstract;      -- Must be overriden
-      return False;
-   end Is_Null;
-
    function Column_Is_Null(Q : Root_Query_Type'Class; CX : Column_Index_Type) return Ind_Type is
    begin
       return Ind_Type(Is_Null(Root_Query_Type'Class(Q),CX));
@@ -1373,7 +1229,6 @@
 
    procedure Date_Fetch(Query : Root_Query_Type'Class; CX : Column_Index_Type; V : out Val_Type; Indicator : out Ind_Type) is
       function Value is new Date_Value(Val_Type);
-      D : APQ_Date;
    begin
       Indicator := Ind_Type( Is_Null(Root_Query_Type'Class(Query),CX) );
       if not Indicator then

[-- Attachment #3: Type: text/plain, Size: 40 bytes --]

-- 
Brian May <bam@snoopy.apana.org.au>