public Parser()
{
RootNode = new Root();
Variables = new List<VariableInfo>();
Tokens = new List<Token>();
SetKeywords();
SetVariables();
}
/// <summary>
/// <IFSTATEMENT> := 'IF (' <CONDITION> ')' <STATEMENTS> 'END'
/// If statements within if statements do not work
/// </summary>
private Node ParseIfStatement(Node node, ref Node currentNodeMarker)
{
node = new Node();
node.Value = "IF";
TokenIndex++;
//Semantics
if (!GetCurrentToken().Value.Equals("("))
Console.Write("Enclose the condition in (...)");
TokenIndex++;
//Parse the condition in the left child of the IF node
node.Left = ParseCondition(node.Left);
//Semantics
if (!GetCurrentToken().Value.Equals(")"))
Console.Write("Enclose the condition in (...)");
//Skip the right bracket and new line
TokenIndex++;
TokenIndex++;
//Create a root class node for the top of the IF tree
Root root = new Root();
//Insert the IF node in the root
root.Insert(node.Value, node.Left);
//Mark the current node and set it
currentNodeMarker = node.Right;
Node currentNode = node.Right;
//Parse statements until END is found
while (!GetCurrentToken().Value.Equals("END"))
{
if (GetCurrentToken().Type.Equals(TokenType.EOL))
{
TokenIndex++;
}
//Insert the statements in
currentNode = ParseStatement(currentNode, ref currentNodeMarker);
if (currentNode != null)
{
root.Insert("STATEMENTS", currentNode);
currentNode = currentNode.Right;
currentNodeMarker = currentNode;
}
TokenIndex++;
}
//The final right node will always be empty, so remove it
root.NullifyEmptyChildren();
return (Node)root;
}