private RegularExpression(PartialExpression part)
{
input = part.ToString();
parsedInput = part;
TagInput();
CountTags();
}
/// <summary>
/// Copy constructor. Constructs a complete copy of all subexpressions.
/// </summary>
/// <param name="origin">original partial expression</param>
public PartialExpression(PartialExpression origin)
{
if (origin == null)
{
throw new ArgumentNullException("origin");
}
role = origin.role;
root = origin.root;
_value = origin._value;
_operator = origin._operator;
if (role == PartialExpressionRole.Union || role == PartialExpressionRole.Concatenation)
{
if (origin.parts.Count >= 2)
{
parts = new List <PartialExpression>(new PartialExpression[origin.parts.Count]);
Parallel.For(0, origin.parts.Count, (int n) =>
{
parts[n] = new PartialExpression(origin.parts[n]);
parts[n].root = this;
});
}
else if (origin.parts.Count == 1)
{
parts = new List <PartialExpression>(1);
var partCopy = new PartialExpression(origin.parts[0]);
partCopy.root = this;
parts.Add(partCopy);
}
}
}
private RegularExpression(RegularExpression origin)
{
input = origin.input;
alphabet = new List <string>(origin.alphabet);
taggedInput = new List <KeyValuePair <string, InputSymbolTag> >(origin.taggedInput);
tagCount = new Dictionary <InputSymbolTag, uint>(origin.tagCount);
parsedInput = new PartialExpression(origin.parsedInput);
}
/// <summary>
/// Derives a new expression by removing a given letter from the beginning
/// of this regular expression.
/// </summary>
/// <param name="removedLetter">a one-letter string, it must belong to the alphabet of the input</param>
/// <returns>a derived expression, or null if no valid expression could be derived</returns>
public RegularExpression Derive(string removedLetter)
{
if (removedLetter == null)
{
throw new ArgumentNullException("removedLetter", "cannot remove non-existing letter");
}
if (removedLetter.Length != 1)
{
throw new ArgumentException("a single letter must be given", "removedLetter");
}
RegularExpression regexp = null;
lock (derivationCacheLock)
{
Dictionary <char, RegularExpression> regexpList;
if (derivationCache.TryGetValue(this, out regexpList))
{
if (regexpList.TryGetValue(removedLetter[0], out regexp))
{
return(regexp);
}
}
}
if (alphabet.Contains(removedLetter))
{
var parseTreeCopy = new PartialExpression(parsedInput);
parseTreeCopy.Derive(removedLetter);
parseTreeCopy.Optimize();
if (parseTreeCopy.Role.Equals(PartialExpressionRole.Invalid))
{
return(null);
}
regexp = new RegularExpression(parseTreeCopy);
}
lock (derivationCacheLock)
{
Dictionary <char, RegularExpression> regexpList;
if (derivationCache.TryGetValue(this, out regexpList))
{
if (!regexpList.ContainsKey(removedLetter[0]))
{
regexpList.Add(removedLetter[0], regexp);
}
}
else
{
regexpList = new Dictionary <char, RegularExpression>();
regexpList.Add(removedLetter[0], regexp);
derivationCache.Add(this, regexpList);
}
}
return(regexp);
}
public WindowSimpleCanvas(PartialExpression parseTree)
{
this.parseTree = parseTree;
DataContext = this;
InitializeComponent();
ParseTreeDrawing.Draw(ParseTreeCanvas, parseTree);
}
/// <summary>
/// Constructs a new regular expression part.
/// </summary>
/// <param name="role"></param>
/// <param name="root"></param>
public PartialExpression(PartialExpressionRole role, PartialExpression root)
{
this.role = role;
this.root = root;
this.parts = null;
this._value = null;
this._operator = UnaryOperator.None;
}
private void ParseInput()
{
int lastSymbol;
parsedInput = ParseSubExpression(0, out lastSymbol);
if (lastSymbol < taggedInput.Count - 1)
{
throw new ArgumentException("parsing is incomplete");
}
}
/// <summary>
/// Inserts a new part to list of sub-parts that are concatenated with each other.
/// </summary>
/// <param name="index"></param>
/// <param name="exp"></param>
public void InsertToConcatenation(int index, PartialExpression exp)
{
if (exp == null)
{
throw new ArgumentNullException("exp");
}
if (role != PartialExpressionRole.Concatenation)
{
throw new ArgumentException("cannot concatenate symbol with a partial expression that does not store concatenation");
}
if (parts == null)
{
parts = new List <PartialExpression>();
}
parts.Insert(index, exp);
exp.root = this;
}
//public PartialExpression(PartialExpression root)
// : this()
//{
// this.root = root;
//}
//public PartialExpression(PartialExpression root, string value)
// : this(root)
//{
// this._value = value;
//}
/// <summary>
/// Adds a new part to list of sub-parts that are in alternative with each other.
/// </summary>
/// <param name="exp"></param>
public void AddToUnion(PartialExpression exp)
{
if (exp == null)
{
throw new ArgumentNullException("exp");
}
if (role != PartialExpressionRole.Union)
{
throw new ArgumentException("cannot add symbol to a partial expression that does not store union");
}
if (parts == null)
{
parts = new List <PartialExpression>();
}
parts.Add(exp);
exp.root = this;
}
private PartialExpression(PartialExpression origin, bool skipFirstPart)
{
role = origin.role;
root = origin.root;
_value = origin._value;
_operator = origin._operator;
if (role == PartialExpressionRole.Union || role == PartialExpressionRole.Concatenation)
{
parts = new List <PartialExpression>();
int i = 0;
if (skipFirstPart)
{
++i;
}
for (; i < origin.parts.Count; ++i)
{
var part = new PartialExpression(origin.parts[i]);
parts.Add(part);
part.root = this;
}
}
}
/// <summary>
/// Checks for equality between this PartialExpression and another object.
/// </summary>
/// <param name="part"></param>
/// <param name="compareOperators"></param>
/// <returns></returns>
public bool ContentEquals(PartialExpression part, bool compareOperators)
{
if (part == null)
{
return(false);
}
if (this == part)
{
return(true);
}
if (role != part.role)
{
return(false);
}
if (compareOperators)
{
if (_operator != part._operator)
{
return(false);
}
}
switch (role)
{
case PartialExpressionRole.EmptyWord:
return(true);
case PartialExpressionRole.Letter:
return(_value.Equals(part._value));
case PartialExpressionRole.Concatenation:
{
if (parts.Count != part.parts.Count)
{
return(false);
}
for (int i = 0; i < parts.Count; ++i)
{
if (!parts[i].Equals(part.parts[i]))
{
return(false);
}
}
return(true);
}
case PartialExpressionRole.Union:
{
foreach (var p in parts)
{
if (part.parts.Count(x => x.Equals(p)) == 0)
{
return(false);
}
}
foreach (var p in part.parts)
{
if (parts.Count(x => x.Equals(p)) == 0)
{
return(false);
}
}
return(true);
}
case PartialExpressionRole.Undetermined:
case PartialExpressionRole.Invalid:
default:
return(true);
}
// return base.Equals(obj);
}
private void DeriveConcatenation(string removedLetter)
{
var firstPart = parts[0];
if (firstPart._operator == UnaryOperator.KleeneStar)
{
// derivation can split into two variants
// (a^*)bc becomes (bc)+(a(a^*)bc) and only then it is derived
var new1 = new PartialExpression(this, true);
if (new1.parts.Count == 1)
{
new1.Optimize();
}
//new1.root = this;
PartialExpression new2firstPart = new PartialExpression(firstPart);
new2firstPart._operator = UnaryOperator.None;
var new2 = new PartialExpression(this);
new2.InsertToConcatenation(0, new2firstPart);
parts = null;
role = PartialExpressionRole.Union;
AddToUnion(new1);
AddToUnion(new2);
Derive(removedLetter);
}
else if (firstPart.role == PartialExpressionRole.Union &&
firstPart.parts.Any(x => x.role == PartialExpressionRole.EmptyWord))
{
// this union contains an empty word, so the derivation can be split in two variants
// (a+.)bc becomes (abc)+(bc) and only then it is derived
PartialExpression new1firstPart = new PartialExpression(firstPart);
new1firstPart.parts.RemoveAll(x => x.role == PartialExpressionRole.EmptyWord);
var new1 = new PartialExpression(this);
new1.parts[0] = new1firstPart; // instead
new1firstPart.root = new1;
new1.root = this;
var new2 = new PartialExpression(this, true);
if (new2.parts.Count == 1)
{
new2.Optimize();
}
new2.root = this;
role = PartialExpressionRole.Union;
parts = new List <PartialExpression> {
new1, new2
};
Derive(removedLetter);
}
else
{
parts[0].Derive(removedLetter);
if (parts[0].role == PartialExpressionRole.Invalid)
{
parts = null;
role = PartialExpressionRole.Invalid;
}
else if (parts.Count > 1)
{
if (parts[0].role == PartialExpressionRole.EmptyWord)
{
parts.RemoveAt(0);
Optimize();
}
}
else if (parts[0].role == PartialExpressionRole.EmptyWord)
{
parts = null;
role = PartialExpressionRole.EmptyWord;
}
}
}
/// <summary>
/// The derivation is performed in-place, therefore it is good to make a backup of instance
/// if the original is expected to be of some use later.
/// </summary>
/// <param name="removedLetter">string containing a single letter</param>
public void Derive(string removedLetter)
{
// to properly derive expressions with unary operators, they have to be transformed
switch (_operator)
{
case UnaryOperator.KleeneStar:
{
// (a)^* becomes .+a(a)^* because those expressions are equivalent
var extracted = new PartialExpression(this);
extracted._operator = UnaryOperator.None;
var remaining = new PartialExpression(this);
var concat = new PartialExpression(PartialExpressionRole.Concatenation, this);
concat.AddToConcatenation(extracted);
concat.AddToConcatenation(remaining);
parts = null;
role = PartialExpressionRole.Union;
AddToUnion(new PartialExpression(PartialExpressionRole.EmptyWord, this));
AddToUnion(concat);
_operator = UnaryOperator.None;
} break;
case UnaryOperator.KleenePlus:
{
// (a)^+ becomes a(a)^* because those expressions are equivalent
var extracted = new PartialExpression(this);
extracted._operator = UnaryOperator.None;
var remaining = new PartialExpression(this);
remaining._operator = UnaryOperator.KleeneStar;
parts = null;
role = PartialExpressionRole.Concatenation;
AddToConcatenation(extracted);
AddToConcatenation(remaining);
_operator = UnaryOperator.None;
} break;
}
switch (role)
{
case PartialExpressionRole.EmptyWord:
role = PartialExpressionRole.Invalid;
break;
case PartialExpressionRole.Letter:
if (_value.Equals(removedLetter))
{
role = PartialExpressionRole.EmptyWord;
}
else
{
role = PartialExpressionRole.Invalid;
}
_value = null;
break;
case PartialExpressionRole.Concatenation:
DeriveConcatenation(removedLetter);
break;
case PartialExpressionRole.Union:
DeriveUnion(removedLetter);
break;
default:
throw new ArgumentException("encountered partial expression with role that is not allowed");
}
}
///// <summary>
///// Constructs a new regular expression part.
///// </summary>
///// <param name="root"></param>
///// <param name="parts"></param>
///// <param name="concatenation"></param>
//private PartialExpression(PartialExpression root, List<PartialExpression> parts, bool concatenation)
// : this(concatenation ? PartialExpressionRole.Concatenation : PartialExpressionRole.Union, root)
//{
// this.parts = parts;
//}
/// <summary>
/// Constructs a new regular expression part.
/// </summary>
/// <param name="root"></param>
/// <param name="value"></param>
public PartialExpression(PartialExpression root, string value)
: this(PartialExpressionRole.Letter, root)
{
this._value = value;
}
public WindowUserHelp(PhiniteSettings settings, object machineOperationsLock, FiniteStateMachine machine)
{
if (machineOperationsLock == null)
{
throw new ArgumentNullException("machineOperationsLock");
}
if (machine == null)
{
throw new ArgumentNullException("machine");
}
this.settings = settings;
fsmLock = machineOperationsLock;
fsm = machine;
//lock (fsmLock)
{
states = fsm.States;
accepting = fsm.AcceptingStates;
newExpression = fsm.NextNotLabeledState;
parseTree = newExpression.ParseTree;
newExpressionSimilarities = fsm.NextNotLabeledStateSimilarities;
}
newExpressionProcessed = false;
expressionIsSelected = false;
selectedExpression = -1;
labeledExpressionsData = null;
DataContext = this;
InitializeComponent();
ParseTreeDrawing.Draw(ParseTreeCanvas, parseTree);
var data = new List <Tuple <RegularExpression, string, string, string> >();
int i = 0;
foreach (var state in states)
{
var stateIsAccepting = accepting.Contains(state);
StringBuilder s = new StringBuilder();
if (i == 0)
{
s.Append("initial state");
}
if (stateIsAccepting)
{
if (i == 0)
{
s.Append(", ");
}
s.Append("accepting state");
}
//double similarity = newExpression.Similarity(state);
data.Add(new Tuple <RegularExpression, string, string, string>(state, String.Format("q{0}", i), s.ToString(),
String.Format("{0:0.00}%", newExpressionSimilarities[i] * 100)));
++i;
}
LabeledExpressionsData = data;
}
/// <summary>
/// Clears the canvas and draws the parse tree on it.
/// </summary>
/// <param name="canvas">the canvas</param>
/// <param name="parseTree">the parse tree to be drawn</param>
public static void Draw(Canvas canvas, PartialExpression parseTree)
{
DrawParseTree(canvas, parseTree);
}
private PartialExpression ParseSubExpression(int startingIndex, out int lastIndex)
{
var returned = new PartialExpression(PartialExpressionRole.Undetermined, null);
lastIndex = startingIndex;
PartialExpression current = returned;
for (int i = startingIndex; i < taggedInput.Count; ++i)
{
var tagPair = taggedInput[i];
switch (tagPair.Value)
{
case InputSymbolTag.Letter:
{
current.Role = PartialExpressionRole.Concatenation;
current.AddToConcatenation(new PartialExpression(current, tagPair.Key));
} break;
case InputSymbolTag.EmptyWord:
{
current.Role = PartialExpressionRole.Concatenation;
current.AddToConcatenation(new PartialExpression(PartialExpressionRole.EmptyWord, current));
} break;
case InputSymbolTag.Union:
{
if (current.Root == null)
{
var newCurrent = new PartialExpression(PartialExpressionRole.Undetermined, null);
//var newRoot = new PartialExpression(null, new List<PartialExpression> { current, newCurrent }, false);
var newRoot = new PartialExpression(PartialExpressionRole.Union, null);
newRoot.AddToUnion(current);
newRoot.AddToUnion(newCurrent);
current.Root = newRoot;
newCurrent.Root = newRoot;
if (returned == current)
{
returned = newRoot;
}
current = newCurrent;
}
else if (current.Root.Role.Equals(PartialExpressionRole.Union) &&
current.Root.Parts.Contains(current))
{
var newCurrent = new PartialExpression(PartialExpressionRole.Undetermined, current.Root);
current.Root.AddToUnion(newCurrent);
current = newCurrent;
}
else
{
throw new NotImplementedException("more handling code needed");
}
} break;
case InputSymbolTag.OpeningParenthesis:
{
int last = 0;
var subExpr = ParseSubExpression(i + 1, out last);
current.Role = PartialExpressionRole.Concatenation;
current.AddToConcatenation(subExpr);
subExpr.Root = current;
i = last;
} break;
case InputSymbolTag.ClosingParenthesis:
{
lastIndex = i;
return(returned);
}
case InputSymbolTag.KleeneStar:
case InputSymbolTag.KleenePlus:
{
current.Parts[current.Parts.Count - 1].Operator = (UnaryOperator)tagPair.Value;
//current.LastConcatenatedSymbol.Operator = (UnaryOperator)input.Value;
} break;
default:
{
throw new NotImplementedException("more handling code needed");
}
}
lastIndex = i;
}
return(returned);
}
private static Point DrawParseTree(Canvas canvas, PartialExpression parseTree, double x = 0, double y = 0)
{
var canvasContent = canvas.Children;
bool root = x == 0 && y == 0;
if (root)
{
x = ParseTreeDrawingRootOffset.X;
y = ParseTreeDrawingRootOffset.Y;
canvasContent.Clear();
}
int treeWidth = parseTree.CalculateTreeWidth();
double actualX = x;
double actualY = y;
if (treeWidth > 1)
{
double subtreeDrawingHeight = (treeWidth - 1) * (ParseTreeNodeSize.Height + ParseTreeNodeSpacing.Y);
actualY += subtreeDrawingHeight / 2;
}
#region an indicator
var indicator = new Ellipse();
indicator.Fill = Brushes.DarkViolet;
indicator.Width = 6;
indicator.Height = indicator.Width;
canvasContent.Add(indicator);
Canvas.SetLeft(indicator, actualX - indicator.Width / 2);
Canvas.SetTop(indicator, actualY - indicator.Height / 2);
Canvas.SetZIndex(indicator, -1000);
#endregion
#region border for text block
var border = new Ellipse();
border.Stroke = Brushes.Gray;
border.Fill = Brushes.White;
border.StrokeThickness = 1;
border.Width = ParseTreeNodeSize.Width;
border.Height = ParseTreeNodeSize.Height;
canvasContent.Add(border);
Canvas.SetLeft(border, actualX - ParseTreeNodeSize.Width / 2);
Canvas.SetTop(border, actualY - ParseTreeNodeSize.Height / 2);
#endregion
#region text block
var elem = new TextBlock();
elem.TextAlignment = TextAlignment.Center;
elem.Width = ParseTreeNodeContentSize.Width;
elem.Height = ParseTreeNodeContentSize.Height;
canvasContent.Add(elem);
Canvas.SetLeft(elem, actualX - ParseTreeNodeContentSize.Width / 2);
Canvas.SetTop(elem, actualY - ParseTreeNodeContentSize.Height / 2);
#endregion
string text = String.Empty;
if (parseTree.Role == PartialExpressionRole.EmptyWord)
{
text = "epsilon";
}
else if (parseTree.Role == PartialExpressionRole.Letter)
{
text = parseTree.Value;
}
else if ((parseTree.Role & PartialExpressionRole.InternalNode) > 0)
{
if (parseTree.Role == PartialExpressionRole.Concatenation)
{
text = "concat";
}
else if (parseTree.Role == PartialExpressionRole.Union)
{
text = "union";
}
double yy = y;
foreach (var part in parseTree.Parts)
{
#region edge
var edge = new Polyline();
edge.Stroke = Brushes.Gray;
edge.StrokeThickness = 2;
edge.Points.Add(new Point(EdgeHorizontalMargin, actualY));
edge.Points.Add(new Point(ParseTreeNodeSpacing.X - 2 * EdgeHorizontalMargin, yy));
canvasContent.Add(edge);
Canvas.SetLeft(edge, actualX + ParseTreeNodeSize.Width / 2);
//Canvas.SetTop(edge, ParseTreeNodeSize.Height / 2);
Canvas.SetZIndex(edge, -500);
#endregion
var rootPt = DrawParseTree(canvas, part, x + ParseTreeNodeSize.Width + ParseTreeNodeSpacing.X, yy);
int partWidth = part.CalculateTreeWidth();
if (partWidth > 1)
{
var pt = edge.Points[1];
edge.Points[1] = new Point(pt.X, rootPt.Y);
}
yy += partWidth * (ParseTreeNodeSize.Height + ParseTreeNodeSpacing.Y);
}
}
if (parseTree.Operator != UnaryOperator.None)
{
text += RegularExpression.TagsStrings[(InputSymbolTag)parseTree.Operator];
}
elem.Text = text;
if (root)
{
#region start line
var startLine = new Polyline();
startLine.Stroke = Brushes.Gray;
startLine.StrokeThickness = 2;
startLine.Points.Add(new Point(0, 0));
startLine.Points.Add(new Point(RootLineLength, 0));
canvasContent.Add(startLine);
Canvas.SetLeft(startLine, actualX - ParseTreeNodeSize.Width / 2 - RootLineLength);
Canvas.SetTop(startLine, actualY);
Canvas.SetZIndex(startLine, -500);
#endregion
double treeHeight = parseTree.CalculateTreeHeight();
canvas.Width = (treeHeight - 1) * (ParseTreeNodeSize.Width + ParseTreeNodeSpacing.X)
+ ParseTreeNodeSize.Width / 2 + ParseTreeDrawingRootOffset.X;
canvas.Height = (treeWidth - 1) * (ParseTreeNodeSize.Height + ParseTreeNodeSpacing.Y)
+ ParseTreeNodeSize.Height / 2 + ParseTreeDrawingRootOffset.Y;
}
return(new Point(actualX, actualY));
}
