(*
Copyright 2021 Anton Krotov
This file is part of CEdit.
CEdit is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
CEdit is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with CEdit. If not, see <http://www.gnu.org/licenses/>.
*)
MODULE ChangeLog;
IMPORT List, Lines, (*API,*) SYSTEM;
TYPE
tIntItem = POINTER TO RECORD (List.tItem)
adr, val: INTEGER
END;
tBoolItem = POINTER TO RECORD (List.tItem)
adr: INTEGER; val: BOOLEAN
END;
(*
tUntypedPtr = POINTER TO RECORD (List.tItem)
p: INTEGER
END;
tTypedPtr = POINTER TO RECORD (List.tItem)
p: List.tItem
END;
*)
tGuard* = POINTER TO RECORD (List.tItem)
END;
VAR
Log*: List.tList;
guard: tGuard;
isLast: BOOLEAN;
PROCEDURE isLastGuard* (guard: tGuard): BOOLEAN;
VAR
item: List.tItem;
res: BOOLEAN;
BEGIN
IF guard # NIL THEN
item := Log.last;
WHILE ~(item IS tGuard) DO
item := item.prev
END;
res := guard = item
ELSE
res := TRUE
END
RETURN res
END isLastGuard;
PROCEDURE isFirstGuard* (guard: tGuard): BOOLEAN;
VAR
item: List.tItem;
BEGIN
ASSERT(guard # NIL);
item := Log.first;
WHILE ~(item IS tGuard) DO
item := item.next
END
RETURN guard = item
END isFirstGuard;
PROCEDURE setGuard* (_guard: tGuard);
BEGIN
guard := _guard;
isLast := isLastGuard(_guard)
END setGuard;
PROCEDURE redo* (item: List.tItem);
BEGIN
IF item IS tIntItem THEN
SYSTEM.PUT(item(tIntItem).adr, item(tIntItem).val)
ELSIF item IS tBoolItem THEN
SYSTEM.PUT(item(tBoolItem).adr, item(tBoolItem).val)
END
END redo;
PROCEDURE clear (guard: tGuard);
VAR
item: List.tItem;
(*res: INTEGER;*)
BEGIN
isLast := TRUE;
REPEAT
item := List.pop(Log);
IF item # guard THEN
(*
IF item IS tUntypedPtr THEN
res := API._DISPOSE(item(tUntypedPtr).p)
ELSIF item IS tTypedPtr THEN
DISPOSE(item(tTypedPtr).p)
END;*)
DISPOSE(item)
END
UNTIL item = guard;
List.append(Log, item)
END clear;
PROCEDURE changeWord (adrV, adrX: INTEGER);
VAR
item: tIntItem;
BEGIN
NEW(item);
item.adr := adrV;
SYSTEM.GET(adrX, item.val);
IF ~isLast THEN
clear(guard)
END;
List.append(Log, item)
END changeWord;
PROCEDURE changeBool (VAR v: BOOLEAN; x: BOOLEAN);
VAR
item: tBoolItem;
BEGIN
NEW(item);
item.adr := SYSTEM.ADR(v);
item.val := x;
IF ~isLast THEN
clear(guard)
END;
List.append(Log, item)
END changeBool;
PROCEDURE changeInt (VAR v: INTEGER; x: INTEGER);
BEGIN
changeWord(SYSTEM.ADR(v), SYSTEM.ADR(x))
END changeInt;
PROCEDURE changePtr (VAR v: List.tItem; x: List.tItem);
BEGIN
changeWord(SYSTEM.ADR(v), SYSTEM.ADR(x))
END changePtr;
(*
PROCEDURE typedPtr (p: List.tItem);
VAR
item: tTypedPtr;
BEGIN
NEW(item);
item.p := p;
List.append(Log, item)
END typedPtr;
PROCEDURE untypedPtr (p: INTEGER);
VAR
item: tUntypedPtr;
BEGIN
NEW(item);
item.p := p;
List.append(Log, item)
END untypedPtr;
*)
BEGIN
guard := NIL;
isLast := TRUE;
List.init(changeInt, changePtr);
Lines.init(changeInt, changePtr, changeBool(*, typedPtr, untypedPtr*));
Log := List.create(NIL)
END ChangeLog.