//Parses function calls with parameters
private TreeNode function_call(TreeNode Parent)
{
currentToken--;
TreeNode fnHeader = new TreeNode("Function Call", NodeClass.FunctionCall);
Parent.AssociateNode(fnHeader);
if (match(Refrence.Class.Assignment_Identifier))
{
fnHeader.append_child(new TreeNode("Function Name", _tokens[currentToken]));
}
currentToken++;
match(Refrence.Class.LeftBracket);
currentToken++;
//TreeNode Attributes = new TreeNode("Parameters",NodeClass.Scope);
int parameterCount = 1;
while (_tokens[currentToken].Type != Refrence.Class.RightBracket)
{
TreeNode Px = exp(fnHeader);
if (Px == null)
{
return(null);
}
parameterCount++;
fnHeader.append_child(Px);
if (_tokens[currentToken].Type == Refrence.Class.RightBracket || !match(Refrence.Class.Comma))
{
break;
}
currentToken++;
}
currentToken++;
return(fnHeader);
}
private TreeNode exp(TreeNode Parent)
{
TreeNode root = new TreeNode("Expression", NodeClass.Expression);
Parent.AssociateNode(root);
TreeNode Tx = simple_exp(root);
if (Tx != null && Tx.DataType != Datatype.NULL)
{
root.append_child(Tx);
}
else
{
return(null);
}
while (currentToken < _tokens.Count && (_tokens[currentToken].Type == Refrence.Class.ComparisonOperatorLessThan ||
_tokens[currentToken].Type == Refrence.Class.ComparisonOperatorEQ ||
_tokens[currentToken].Type == Refrence.Class.ComparisonOperatorGreaterThan ||
_tokens[currentToken].Type == Refrence.Class.ComparisonOperatorNQ) ||
_tokens[currentToken].Type == Refrence.Class.LogicOperatorAND ||
_tokens[currentToken].Type == Refrence.Class.LogicOperatorOR)
{
root.append_child(new TreeNode("Operator", _tokens[currentToken]));
match(_tokens[currentToken].Type);
currentToken++;
root.append_child(simple_exp(root));
}
return(root);
}
//Invoked in case of identifier intiating statment variable := or variable(.)...etc
//May be used in operator overloading and dot operator functions
//Applications are limitless
private TreeNode identifier_call(TreeNode Parent)
{
TreeNode identifierNode = new TreeNode("Runtime Statment", NodeClass.RuntimeCall);
Parent.AssociateNode(identifierNode);
identifierNode.append_child(new TreeNode("Calling Identifier", _tokens[currentToken]));
currentToken++;
identifierNode.append_child(statement(identifierNode));
identifierNode.Composite = true;
return(identifierNode);
}
private TreeNode read_stmt(TreeNode Parent)
{
TreeNode root = new TreeNode("Read Statment", NodeClass.Directive);
Parent.AssociateNode(root);
match(Refrence.Class.Directive_read);
root.append_child(new TreeNode("Read Directive", _tokens[currentToken]));
currentToken++;
root.append_child(exp(root));
return(root);
}
private TreeNode write_stmt(TreeNode Parent)
{
TreeNode root = new TreeNode("Write Statment", NodeClass.Directive);
Parent.AssociateNode(root);
match(Refrence.Class.Directive_write);
root.append_child(new TreeNode(("Write Directive"), _tokens[currentToken]));
currentToken++;
root.append_child(exp(root));
return(root);
}
private TreeNode assign_stmt(TreeNode Parent)
{
TreeNode root = new TreeNode("Assign", NodeClass.Assignment);
Parent.AssociateNode(root);
match(Refrence.Class.AssignmentOperator);
currentToken++;
root.append_child(exp(root));
return(root);
}
//Parses the 2nd half of the function declaration Function Name (Attributes)
private TreeNode function_sig(TreeNode Parent)
{
currentToken--;
TreeNode fnHeader = new TreeNode("Function signature", NodeClass.FunctionSignature);
Parent.AssociateNode(fnHeader);
if (match(Refrence.Class.Assignment_Identifier))
{
fnHeader.append_child(new TreeNode("Function Name", _tokens[currentToken]));
}
currentToken++;
match(Refrence.Class.LeftBracket);
currentToken++;
int sigDec = 1;
while (_tokens[currentToken].Type != Refrence.Class.RightBracket)
{
TreeNode Tn = new TreeNode("Signature Declaration# " + sigDec++.ToString(), NodeClass.Declaration);
fnHeader.AssociateNode(Tn);
if (_tokens[currentToken].Type == Refrence.Class.DataType_int ||
_tokens[currentToken].Type == Refrence.Class.DataType_float ||
_tokens[currentToken].Type == Refrence.Class.DataType_string)
{
Tn.append_child(new TreeNode("Datatype", _tokens[currentToken++]));
}
else
{
ErrorList.Add(new Error("Unexpected lexeme in Line %LINE%, A datatype expected".Replace("%LINE%", _tokens[currentToken].Line.ToString()), Error.ErrorType.ParserError));
}
if (_tokens[currentToken].Type == Refrence.Class.Assignment_Identifier)
{
Tn.append_child(new TreeNode("Identifier", _tokens[currentToken++]));
}
else
{
ErrorList.Add(new Error("Unexpected lexeme in Line %LINE%, identifier expected".Replace("%LINE%", _tokens[currentToken].Line.ToString()), Error.ErrorType.ParserError));
}
fnHeader.append_child(Tn);
if (_tokens[currentToken].Type == Refrence.Class.RightBracket || !match(Refrence.Class.Comma))
{
break;
}
currentToken++;
}
currentToken++;
fnHeader.append_child(function_body(fnHeader));
fnHeader.Composite = true;
return(fnHeader);
}
private TreeNode stmt_sequence(TreeNode Parent)
{
TreeNode seq_root = new TreeNode("Statements sequence", NodeClass.Scope);
Parent.AssociateNode(seq_root);
while (currentToken != _tokens.Count)
{
TreeNode child = statement(seq_root);
if (child != null)
{
seq_root.append_child(child);
}
}
return(seq_root);
}
private TreeNode term(TreeNode Parent)
{
TreeNode root = new TreeNode("Term", NodeClass.Term);
Parent.AssociateNode(root);
TreeNode Tx = factor(root);
if (Tx != null)
{
root.append_child(Tx);
}
else
{
return(null);
}
while (currentToken < _tokens.Count && (_tokens[currentToken].Type == Refrence.Class.ArithmeticMultiplication ||
_tokens[currentToken].Type == Refrence.Class.ArithmeticDivision))
{
TreeNode operatorNode = new TreeNode("Operator", _tokens[currentToken]);
match(_tokens[currentToken].Type);
currentToken++;
TreeNode child = factor(root);
if (root.Children.Count == 0)
{
root.Attributes[Attribute.Datatype] = child.DataType;
root.append_child(operatorNode);
root.append_child(child);
}
if (root.Children.Count == 2)
{
TreeNode leftChild = root;
root = new TreeNode("Term", NodeClass.Term);
root.append_child(leftChild);
root.append_child(operatorNode);
root.append_child(child);
}
else
{
root.append_child(operatorNode);
root.append_child(child);
}
}
return(root);
}
private TreeNode simple_exp(TreeNode Parent)
{
TreeNode root = new TreeNode("Simple expression", NodeClass.SimpleExpression);
Parent.AssociateNode(root);
TreeNode Tx = term(root);
if (Tx != null && Tx.DataType != Datatype.NULL)
{
root.append_child(Tx);
}
else
{
return(null);
}
while (currentToken < _tokens.Count && (_tokens[currentToken].Type == Refrence.Class.ArithmeticAddition ||
_tokens[currentToken].Type == Refrence.Class.Arithmeticsubtraction ||
_tokens[currentToken].Type == Refrence.Class.ArithmeticsubtractionOperator2))
{
TreeNode operatorNode = new TreeNode("Operator", _tokens[currentToken]);
match(_tokens[currentToken].Type);
currentToken++;
TreeNode child = term(root);
if (root.Children.Count == 2)
{
TreeNode leftChild = root;
root = new TreeNode("Simple expression", NodeClass.Expression);
root.append_child(leftChild);
root.append_child(operatorNode);
root.append_child(child);
}
else
{
root.append_child(operatorNode);
root.append_child(child);
}
}
return(root);
}
//Repeat bounds parser
private TreeNode repeat_stmt(TreeNode Parent)
{
TreeNode root = new TreeNode("Loop (Repeat)", NodeClass.LoopBound);
Parent.AssociateNode(root);
match(Refrence.Class.LoopBound_repeat);
currentToken++;
TreeNode seQ = new TreeNode("Body", NodeClass.Scope);
root.AssociateNode(seQ);
while (_tokens[currentToken].Type != Refrence.Class.LoopBound_until)
{
seQ.append_child(statement(seQ));
}
match(Refrence.Class.LoopBound_until);
currentToken++;
root.append_child(exp(root));
root.append_child(seQ);
root.Composite = true;
return(root);
}
//Switches the parser to an in function mode
//to avoid nesting functions (lambda may still be made though if intented)
//can handle multiple returns
private TreeNode function_body(TreeNode Parent)
{
Parsers[Refrence.Class.LeftBracket] = function_call;
TreeNode fnBody = new TreeNode("Function body", NodeClass.Scope);
Parent.AssociateNode(fnBody);
currentToken++;
while (currentToken != _tokens.Count)
{
if (_tokens[currentToken].Type == Refrence.Class.RightCurlyBrace)
{
currentToken++;
break;
}
else if (_tokens[currentToken].Type == Refrence.Class.Directive_return)
{
TreeNode returnCode = new TreeNode("Return Statment", NodeClass.Directive);
fnBody.AssociateNode(returnCode);
returnCode.Attributes[Attribute.Datatype] = Parent.Children[0].DataType;
returnCode.append_child(new TreeNode("Return directive", _tokens[currentToken]));
currentToken++;
returnCode.append_child(exp(returnCode));
match(Refrence.Class.SemiColon);
currentToken++;
continue;
}
TreeNode child = statement(fnBody);
if (child != null)
{
fnBody.append_child(child);
}
}
Parsers[Refrence.Class.LeftBracket] = function_sig;
fnBody.Composite = true;
return(fnBody);
}
//Supports multiple declarations via the loop below
private TreeNode declaration_stmt(TreeNode Parent)
{
TreeNode dec_node = new TreeNode("Declaration Statment", NodeClass.Declaration);
Parent.AssociateNode(dec_node);
dec_node.append_child(new TreeNode("Datatype", _tokens[currentToken]));
currentToken++;
if (!match(Refrence.Class.Assignment_Identifier))
{
return(dec_node);
}
while (_tokens[currentToken].Type == Refrence.Class.Assignment_Identifier)
{
dec_node.append_child(new TreeNode("Identifier", _tokens[currentToken]));
currentToken++;
if (_tokens[currentToken].Type == Refrence.Class.AssignmentOperator)
{
dec_node.append_child(assign_stmt(dec_node));
}
if (_tokens[currentToken].Type != Refrence.Class.Comma)
{
break;
}
else
{
currentToken++;
}
}
//Checks in case of function then the statment is composed of declaration and a signature
if (currentToken < _tokens.Count && _tokens[currentToken].Type == Refrence.Class.LeftBracket)
{
dec_node.Composite = true;
}
return(dec_node);
}
//Jigsaw if elseif^n else model
//prevents a dual else or else if preceding else
private TreeNode if_stmt(TreeNode Parent)
{
TreeNode root = new TreeNode("If statement", NodeClass.ifCondition);
Parent.AssociateNode(root);
match(Refrence.Class.BranchingAgent_if);
root.append_child(new TreeNode("If Intiator", _tokens[currentToken]));
currentToken++;
root.append_child(exp(root));
match(Refrence.Class.BranchingAgent_then);
currentToken++;
int ElsesCount = 1;
//seQ is our buffer each time we transfer from an if body to an else/elseif body we
//append seQ and restart all over again in the new body
//We keep track of our elses via Elses count
//which in reality is an if body count
TreeNode seQ = new TreeNode("If Body", NodeClass.Scope);
root.AssociateNode(seQ);
while (_tokens[currentToken].Type != Refrence.Class.BranchingAgent_end)
{
if (_tokens[currentToken].Type == Refrence.Class.BranchingAgent_elseif)
{
if (ElsesCount == 0)
{
ErrorList.Add(new Error("An ElseIf Scope can not be opened following an else scope", Error.ErrorType.ParserError));
}
currentToken++;
root.append_child(seQ);
seQ = new TreeNode("Else If#" + ElsesCount++.ToString(), NodeClass.Scope);
TreeNode ConditionNode = new TreeNode("Condition", NodeClass.Scope);
ConditionNode.append_child(exp(ConditionNode));
seQ.append_child(ConditionNode);
match(Refrence.Class.BranchingAgent_then);
seQ.append_child(new TreeNode("Keyword:", _tokens[currentToken]));
currentToken++;
}
if (_tokens[currentToken].Type == Refrence.Class.BranchingAgent_else)
{
if (ElsesCount == 0)
{
ErrorList.Add(new Error("A single if can not contain 2 else scopes", Error.ErrorType.ParserError));
}
ElsesCount = 0;
currentToken++;
root.append_child(seQ);
seQ = new TreeNode("Else Body", NodeClass.Scope);
}
//All the branching above sets the seQ for this linear statment to append statments from tokens
seQ.append_child(statement(seQ));
if (currentToken == _tokens.Count)
{
ErrorList.Add(CreateError(EndOfFile, "end", root.Children[0].Line));
root.append_child(seQ);
return(root);
}
}
root.append_child(seQ);
match(Refrence.Class.BranchingAgent_end);
currentToken++;
root.Composite = true;
return(root);
}