/// <summary>
/// The second step is to aggregate the operators like ">" "=" in ">="
/// </summary>
/// <param name="nodeItems"></param>
public void AggregateOperators(IList <NodeItem> nodeItems)
{
var todelete = new List <NodeItem>();
NodeItem previous = null;
foreach (var node in nodeItems)
{
if (previous == null)
{
previous = node;
continue;
}
AggregateOperators(node.NodeItems);
if (previous is NodeItemOperator && node is NodeItemOperator)
{
previous.AppendName(node.Name);
todelete.Add(node);
}
previous = node;
}
foreach (var item in todelete)
{
nodeItems.Remove(item);
}
}
/// <summary>
/// Add a child node to the current one
/// </summary>
/// <param name="name">The name of the newly created node</param>
/// <returns>The new node</returns>
public NodeItem AddChild(string name)
{
var newNode = new NodeItem(this, name);
this.NodeItems.Add(newNode);
return(newNode);
}
// Used only for functions so that parameters are the children
private void CommitDownFunction()
{
var text = _builder.ToString().Trim();
_builder.Clear();
_current = _current.AddSiblingFunction(text);
_current = _current.AddChild("");
}
private void Down()
{
if (_current.Parent != null)
{
_current = _current.AddSibling("");
}
_current = _current.AddChild("");
}
/// <summary>
/// Add a sibling node to the current one
/// </summary>
/// <param name="name">The name of the newly created node</param>
/// <returns>The new node</returns>
public NodeItem AddSibling(string name)
{
var newNode = new NodeItem(this.Parent, name);
newNode.Kind = NodeKind.Unknown;
Parent.NodeItems.Add(newNode);
return(newNode);
}
private void Commit()
{
var text = _builder.ToString().Trim();
if (text == string.Empty)
{
return;
}
_builder.Clear();
_current = _current.AddSibling(text);
}
public NodeFunction(NodeItem parent, string name)
: base(parent, name)
{
}
private void Up()
{
_current = _current.Parent;
}
private void CommitSpecial(char symbol)
{
var text = symbol.ToString();
_current = _current.AddSiblingOperator(text);
}
/// <summary>
/// This method tokenize the string expression.
/// It is the very first step to do to parse text and produces
/// a tree structure that will be further elaborated
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public IList <NodeItem> Tokenize(string expression)
{
_builder = new StringBuilder();
var root = new NodeItem(null, ""); // root
_current = root;
bool _lastParenthesisWasNotDown = false;
Down();
foreach (var ch in expression)
{
switch (ch)
{
case '(':
if (BuilderIsEmpty())
{
Down();
}
else
{
//Commit();
//_builder.Append(ch);
_lastParenthesisWasNotDown = true;
CommitDownFunction();
}
break;
case ')':
if (_lastParenthesisWasNotDown)
{
Commit();
//_builder.Append(ch);
//Commit();
Up();
_lastParenthesisWasNotDown = false;
}
else
{
Commit();
Up();
}
break;
case '^':
case '%':
case '!':
case '~':
case '+':
case '-':
case '*':
case '/':
case '>':
case '<':
case '=':
case '&':
case '|':
Commit();
CommitSpecial(ch);
break;
case ',':
Commit();
CommitSpecial(ch);
break;
case ' ':
Commit();
_builder.Append(ch);
Commit();
break;
default:
_builder.Append(ch);
break;
}
}
Commit();
Up();
root.RemoveEmptyChildren();
var str = root.ToString();
Debug.WriteLine(string.Format("Before: {0}\r\nAfter: {1}", expression, str));
if (_current.Parent != null)
{
throw new Exception("Parenthesis error");
}
return(_current.NodeItems);
}
/// <summary>
/// The third step is to assign a category to each node of the tree
/// </summary>
/// <param name="nodeItems"></param>
/// <param name="inputParameters"></param>
public void Categorize(IList <NodeItem> nodeItems, Parameter[] inputParameters)
{
NodeItem previous = null;
foreach (var node in nodeItems)
{
NodeKind kind;
switch (node.Name)
{
case "+": // unary, additive
case "-": // unary, additive
case "!":
case "~":
if (previous is NodeItemOperator)
{
kind = NodeKind.OpUnary;
}
else
{
kind = NodeKind.OpAdditive;
}
break;
case "*":
case "/":
case "%":
kind = NodeKind.OpMultiplicative;
break;
case "<<":
case ">>":
kind = NodeKind.OpShift;
break;
case ">":
case "<":
case "<=":
case ">=":
kind = NodeKind.OpRelational;
break;
case "==":
case "!=":
kind = NodeKind.OpEquality;
break;
case "&":
kind = NodeKind.OpLogicalAnd;
break;
//case "^":
// kind = NodeKind.OpLogicalXor;
// break;
case "|":
kind = NodeKind.OpLogicalOr;
break;
case "&&":
kind = NodeKind.OpConditionalAnd;
break;
case "||":
kind = NodeKind.OpConditionalOr;
break;
case "":
kind = NodeKind.SubExpression;
break;
case "^":
kind = NodeKind.OpCall;
break;
// new
case ",":
kind = NodeKind.Separator;
break;
default:
{
if (inputParameters.Select(n => n.Name).Contains(node.Name))
{
kind = NodeKind.Parameter;
}
else if (node is NodeFunction)
{
kind = NodeKind.Function;
}
else
{
kind = NodeKind.Literal;
}
}
break;
}
node.SetKind(kind);
previous = node;
Categorize(node.NodeItems, inputParameters);
}
}
public NodeItem(NodeItem parent, string name)
{
NodeItems = new List <NodeItem>();
this.Parent = parent;
this.Name = name;
}
public NodeItemOperator(NodeItem parent, string name)
: base(parent, name)
{
}