Implement GSCSTableau, GSCSEditInfo, GSCSEditVariableManager (#186)

* Implement GSCSTableau, GSCSEditInfo, GSCSEditVariableManager

* Update GSTableau based on feedback

* Remove adding expression term variable to external parameteric variables

Source/GSCSEditVariableManager.m

@@ -0,0 +1,141 @@
+/* Copyright (C) 2023 Free Software Foundation, Inc.
+
+   By: Benjamin Johnson
+   Date: 12-6-2023
+   This file is part of the GNUstep Library.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110 USA.
+*/
+
+#import "GSCSEditVariableManager.h"
+#import "GSFastEnumeration.h"
+
+@implementation GSCSEditVariableManager
+
+- (instancetype) init
+{
+  self = [super init];
+  if (self)
+    {
+      ASSIGN(_editVariablesList, [NSMutableArray array]);
+      ASSIGN(_editVariablesStack, [NSMutableArray array]);
+      ASSIGN(_editVariablesMap,
+             [NSMapTable mapTableWithKeyOptions: NSMapTableStrongMemory
+                                   valueOptions: NSMapTableStrongMemory]);
+      [self pushEditVariableCount];
+    }
+  return self;
+}
+
+- (BOOL) isEmpty
+{
+  return [_editVariablesList count] == 0;
+}
+
+- (NSArray *) editInfos
+{
+  return _editVariablesList;
+}
+
+- (NSInteger) editVariableStackCount
+{
+  return [_editVariablesStack count];
+}
+
+- (NSInteger) topEditVariableStack
+{
+  return [[_editVariablesStack lastObject] integerValue];
+}
+
+- (void) pushEditVariableCount
+{
+  [_editVariablesStack
+    addObject: [NSNumber numberWithInteger: [_editVariablesList count]]];
+}
+
+- (void) popEditVariableStack
+{
+  [_editVariablesStack removeLastObject];
+}
+
+- (void) addEditInfo: (GSCSEditInfo *)editInfo
+{
+  [_editVariablesMap setObject: editInfo forKey: [editInfo variable]];
+  [_editVariablesList addObject: editInfo];
+}
+
+- (void) removeEditInfo: (GSCSEditInfo *)editInfo
+{
+  [_editVariablesList removeObject: editInfo];
+}
+
+- (void) removeEditInfoForConstraint: (GSCSConstraint *)constraint
+{
+  GSCSEditInfo *editInfo = [self editInfoForConstraint: constraint];
+  [self removeEditInfo: editInfo];
+}
+
+- (GSCSEditInfo *) editInfoForConstraint: (GSCSConstraint *)constraint
+{
+  FOR_IN(GSCSEditInfo *, editInfo, _editVariablesList)
+    if ([editInfo constraint] == constraint)
+      {
+        return editInfo;
+      }
+  END_FOR_IN(_editVariablesList);
+
+  return nil;
+}
+
+- (NSArray *) editInfosForVariable: (GSCSVariable *)editVariable
+{
+  NSMutableArray *editInfos = [NSMutableArray array];
+  FOR_IN(GSCSEditInfo *, editInfo, _editVariablesList)
+    if ([editInfo variable] == editVariable)
+      {
+        [editInfos addObject: editInfo];
+      }
+  END_FOR_IN(_editVariablesList);
+
+  return editInfos;
+}
+
+- (NSArray *) getNextSet
+{
+  [_editVariablesStack removeLastObject];
+  NSInteger index = [self topEditVariableStack];
+  NSInteger count = [_editVariablesList count];
+  NSMutableArray *editableInfosInDescendingOrder = [NSMutableArray array];
+  while (count > index)
+    {
+      GSCSEditInfo *editInfo = [[self editInfos] objectAtIndex: count - 1];
+      [editableInfosInDescendingOrder addObject: editInfo];
+      count--;
+    }
+
+  return editableInfosInDescendingOrder;
+}
+
+- (void) dealloc
+{
+  RELEASE(_editVariablesList);
+  RELEASE(_editVariablesStack);
+  RELEASE(_editVariablesMap);
+
+  [super dealloc];
+}
+
+@end