------------------------------------------------------------------------------
-- Copyright (c) 2013-2014, Natacha Porté --
-- --
-- Permission to use, copy, modify, and distribute this software for any --
-- purpose with or without fee is hereby granted, provided that the above --
-- copyright notice and this permission notice appear in all copies. --
-- --
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES --
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF --
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR --
-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES --
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN --
-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF --
-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. --
------------------------------------------------------------------------------
package body Natools.S_Expressions.Interpreters is
---------------------
-- Atom Comparison --
---------------------
function Less_Than (Left, Right : Atom) return Boolean is
begin
return Left'Length < Right'Length
or else (Left'Length = Right'Length and then Left < Right);
end Less_Than;
-----------------
-- Interpreter --
-----------------
procedure Add_Command
(Self : in out Interpreter;
Name : in Atom;
Cmd : in Command'Class) is
begin
Self.Commands.Insert (Name, Cmd);
Self.Max_Length := Count'Max (Self.Max_Length, Name'Length);
end Add_Command;
function Has_Command (Self : Interpreter; Name : Atom) return Boolean is
begin
return Self.Commands.Contains (Name);
end Has_Command;
function Is_Empty (Self : Interpreter) return Boolean is
begin
return Self.Commands.Is_Empty;
end Is_Empty;
procedure Set_Fallback
(Self : in out Interpreter;
Name : in Atom)
is
function Create return Atom;
function Create return Atom is
begin
return Name;
end Create;
begin
Self.Fallback_Name.Replace (Create'Access);
end Set_Fallback;
procedure Reset_Fallback (Self : in out Interpreter) is
begin
Self.Fallback_Name.Reset;
end Reset_Fallback;
not overriding procedure Execute
(Self : in out Interpreter;
Expression : in out Lockable.Descriptor'Class;
State : in out Shared_State;
Context : in Shared_Context)
is
Event : Events.Event := Expression.Current_Event;
Lock_State : Lockable.Lock_State;
begin
loop
case Event is
when Events.Add_Atom =>
Self.Execute (State, Context, Expression.Current_Atom);
when Events.Open_List =>
Expression.Lock (Lock_State);
begin
Expression.Next (Event);
if Event = Events.Add_Atom then
Self.Execute (State, Context, Expression);
end if;
exception
when others =>
Expression.Unlock (Lock_State, False);
raise;
end;
Expression.Unlock (Lock_State);
when Events.Close_List | Events.End_Of_Input | Events.Error =>
exit;
end case;
Expression.Next (Event);
end loop;
end Execute;
not overriding procedure Execute
(Self : in out Interpreter;
Fallback : in out Command'Class;
Expression : in out Lockable.Descriptor'Class;
State : in out Shared_State;
Context : in Shared_Context)
is
procedure Dispatch (Process : not null access procedure
(Name : in Atom; Cmd : in out Command'Class));
procedure Process_Atom (Name : in Atom; Cmd : in out Command'Class);
procedure Process_Exp (Name : in Atom; Cmd : in out Command'Class);
procedure Dispatch (Process : not null access procedure
(Name : in Atom; Cmd : in out Command'Class))
is
procedure Process_Fallback (Name : in Atom);
procedure Process_Fallback (Name : in Atom) is
begin
Process (Name, Fallback);
end Process_Fallback;
Buffer : Atom (1 .. Self.Max_Length);
Length : Count;
Cursor : Command_Maps.Cursor;
begin
Expression.Read_Atom (Buffer, Length);
if Length > Self.Max_Length then
Expression.Query_Atom (Process_Fallback'Access);
else
Cursor := Self.Commands.Find (Buffer (1 .. Length));
if Command_Maps.Has_Element (Cursor) then
Self.Commands.Update_Element (Cursor, Process);
else
Process (Buffer (1 .. Length), Fallback);
end if;
end if;
end Dispatch;
procedure Process_Atom (Name : in Atom; Cmd : in out Command'Class) is
begin
Cmd.Execute (State, Context, Name);
end Process_Atom;
procedure Process_Exp (Name : in Atom; Cmd : in out Command'Class) is
pragma Unreferenced (Name);
begin
Cmd.Execute (State, Context, Expression);
end Process_Exp;
Event : Events.Event := Expression.Current_Event;
Lock_State : Lockable.Lock_State;
begin
loop
case Event is
when Events.Add_Atom =>
Dispatch (Process_Atom'Access);
when Events.Open_List =>
Expression.Lock (Lock_State);
begin
Expression.Next (Event);
if Event = Events.Add_Atom then
Dispatch (Process_Exp'Access);
end if;
exception
when others =>
Expression.Unlock (Lock_State, False);
raise;
end;
Expression.Unlock (Lock_State);
when Events.Close_List | Events.End_Of_Input | Events.Error =>
exit;
end case;
Expression.Next (Event);
end loop;
end Execute;
overriding procedure Execute
(Self : in out Interpreter;
State : in out Shared_State;
Context : in Shared_Context;
Name : in Atom)
is
procedure Process_Atom (Key : in Atom; Cmd : in out Command'Class);
procedure Process_Atom (Key : in Atom; Cmd : in out Command'Class) is
pragma Unreferenced (Key);
begin
Cmd.Execute (State, Context, Name);
end Process_Atom;
Cursor : Command_Maps.Cursor;
begin
if Name'Length <= Self.Max_Length then
Cursor := Self.Commands.Find (Name);
if Command_Maps.Has_Element (Cursor) then
Self.Commands.Update_Element (Cursor, Process_Atom'Access);
return;
end if;
end if;
if not Self.Fallback_Name.Is_Empty then
Cursor := Self.Commands.Find (Self.Fallback_Name.Query.Data.all);
if Command_Maps.Has_Element (Cursor) then
Self.Commands.Update_Element (Cursor, Process_Atom'Access);
return;
end if;
end if;
raise Command_Not_Found
with "Unknown command """ & To_String (Name) & '"';
end Execute;
overriding procedure Execute
(Self : in out Interpreter;
State : in out Shared_State;
Context : in Shared_Context;
Cmd : in out Lockable.Descriptor'Class)
is
procedure Process_Exp (Name : in Atom; Actual : in out Command'Class);
procedure Process_Exp (Name : in Atom; Actual : in out Command'Class) is
pragma Unreferenced (Name);
begin
Actual.Execute (State, Context, Cmd);
end Process_Exp;
Buffer : Atom (1 .. Self.Max_Length);
Length : Count;
Cursor : Command_Maps.Cursor;
begin
if Cmd.Current_Event /= Events.Add_Atom then
return;
end if;
Cmd.Read_Atom (Buffer, Length);
if Length <= Self.Max_Length then
Cursor := Self.Commands.Find (Buffer (1 .. Length));
if Command_Maps.Has_Element (Cursor) then
Self.Commands.Update_Element (Cursor, Process_Exp'Access);
return;
end if;
end if;
if not Self.Fallback_Name.Is_Empty then
Cursor := Self.Commands.Find (Self.Fallback_Name.Query.Data.all);
if Command_Maps.Has_Element (Cursor) then
Self.Commands.Update_Element (Cursor, Process_Exp'Access);
return;
end if;
end if;
raise Command_Not_Found
with "Unknown command """ & To_String (Cmd.Current_Atom) & '"';
end Execute;
end Natools.S_Expressions.Interpreters;