public void Visit(ASTWhile whileStatement, Function function)
{
// do condition
int condition = function.Code.Count;
whileStatement.Condition.Accept(this, function);
// branch out if condition evaluates to false
function.Code.Write(OpCodeFactory.BranchIfFalse(0));
int conditionBranch = function.Code.Count - 1;
// compile body
whileStatement.Body.Accept(this, function);
// branch back to the condition
function.Code.Write(OpCodeFactory.Branch((uint)condition));
int end = function.Code.Count;
// set the conditional branch offset
function.Code[conditionBranch].As <BranchIfFalse>().Argument = (uint)end;
// fill breaks/continues
for (int i = condition; i < end; i++)
{
var instruction = function.Code[i];
if (instruction is Branch breakBranch && breakBranch.Argument == Break) // break, jump to end
{
breakBranch.Argument = (uint)end;
}
private static List <ASTNode> ParseCodeBlock()
{
List <ASTNode> codeBlock = new List <ASTNode>();
if (currentToken < currentTokens.Count)
{
if (currentTokens[currentToken].Token == "{")
{
currentToken++;
while (currentToken < currentTokens.Count && currentTokens[currentToken].Token != "}")
{
if (currentTokens[currentToken] is ReservedWordToken && currentTokens[currentToken].Token == "if")
{
ASTIf ifNode = ParseIf();
codeBlock.Add(ifNode);
}
else if (currentTokens[currentToken] is ReservedWordToken && currentTokens[currentToken].Token == "for")
{
ASTFor forNode = ParseFor();
codeBlock.Add(forNode);
}
else if (currentTokens[currentToken] is ReservedWordToken && currentTokens[currentToken].Token == "while")
{
ASTWhile whileNode = ParseWhile();
codeBlock.Add(whileNode);
}
else
{
ASTStatement statement = ParseStatement();
if (statement != null)
{
codeBlock.Add(statement);
}
}
}
if (currentToken == currentTokens.Count)
{
throw new ParserException("SourceCode can't end in Code Block.", -1);
}
return(codeBlock);
}
// No '{' means just one line of code
else
{
ASTStatement statement = ParseStatement();
if (statement != null)
{
codeBlock.Add(statement);
}
return(codeBlock);
}
}
throw new ParserException("Expected Code Block found End of File.", -1);
}
/// <summary>
/// Pretty simple, just ensure that the condition is a boolean.
/// </summary>
/// <param name="n"></param>
public override void VisitWhile(ASTWhile n)
{
CFlatType condType = CheckSubTree(n.Condition);
if (condType is TypeBool)
{
CheckSubTree(n.Body);
}
else
{
ReportError(n.Location, "While loop condition must be a boolean. Got type '{0}'", TypeToFriendlyName(condType));
}
}
private Symbol VisitWhileStatement(ASTWhile node)
{
var conditionType = Visit(node.Condition);
if (conditionType.Name != "bool")
{
ThrowIncompatibleTypesException(node.Token, conditionType.Name, "bool");
}
Logger.DebugScope($"Enter scope : while");
var whileScope = new ScopedSymbolTable("while", _currentScope.Level + 1, _currentScope);
_currentScope = whileScope;
var returnType = Visit(node.Body);
DebugPrintSymbolTable();
_currentScope = _currentScope.EnclosingScope;
Logger.DebugScope($"Leave scope : while");
return(returnType);
}
public override void VisitWhile(ASTWhile n)
{
//define labels
Label loop = _gen.DefineLabel();
Label exit = _gen.DefineLabel();
//loop label
_gen.MarkLabel(loop);
//check condition
n.Condition.Visit(this);
//break on false
_gen.Emit(OpCodes.Brfalse, exit);
//emit body of loop
n.Body.Visit(this);
//unconditional loop branch
_gen.Emit(OpCodes.Br, loop);
//break label
_gen.MarkLabel(exit);
}
private VisitResult VisitWhileStatement(ASTWhile node)
{
var condition = Visit(node.Condition).Value;
while (condition)
{
var result = Visit(node.Body);
if (result != null)
{
switch (result.ControlType)
{
case ControlType.Return:
return(result);
case ControlType.Break:
return(null);
}
}
condition = Visit(node.Condition).Value;
}
return(null);
}
ASTStatement ParseStatement()
{
if (lexer.PeekNext() == TokenType.Identifier) // Function call
{
ASTFuncCall funcCall = ParseExpression() as ASTFuncCall;
return(new ASTInlineCall(funcCall));
}
Token first = lexer.NextToken();
switch (first.Type)
{
case TokenType.Set:
{
Token varNameToken = MatchNext(TokenType.Identifier);
List <ASTExpression> indexers = new List <ASTExpression>();
while (lexer.PeekNext() == TokenType.SquareBraceOpen)
{
MatchNext(TokenType.SquareBraceOpen);
indexers.Add(ParseExpression());
MatchNext(TokenType.SquareBraceClose);
}
MatchNext(TokenType.To);
ASTExpression expression = ParseExpression();
return(new ASTSet(varNameToken.Source, expression, indexers));
}
case TokenType.If:
{
ASTExpression check = ParseExpression();
ASTStatements statements = new ASTStatements();
ASTIf ifStmnt = new ASTIf(check, statements);
MatchNext(TokenType.Do);
while (lexer.PeekNext() != TokenType.End)
{
if (lexer.PeekNext() == TokenType.Else)
{
lexer.NextToken();
statements = new ASTStatements();
ifStmnt.SetElse(statements);
MatchNext(TokenType.Do);
}
else if (lexer.PeekNext() == TokenType.Elif)
{
lexer.NextToken();
statements = new ASTStatements();
ASTIf elseifStmnt = new ASTIf(ParseExpression(), statements);
ifStmnt.SetElseIf(elseifStmnt);
MatchNext(TokenType.Do);
}
statements.AddStatement(ParseStatement());
}
lexer.NextToken();
return(ifStmnt);
}
case TokenType.While:
{
ASTExpression check = ParseExpression();
ASTStatements statements = new ASTStatements();
ASTWhile whileStmnt = new ASTWhile(check, statements);
MatchNext(TokenType.Do);
while (lexer.PeekNext() != TokenType.End)
{
statements.AddStatement(ParseStatement());
}
lexer.NextToken();
return(whileStmnt);
}
case TokenType.Return:
{
return(new ASTReturn(ParseExpression()));
}
default:
throw new Exception("Unexpected token " + first);
}
return(null);
}
private static void PrintNode(ASTNode node, int incident)
{
if (node == null)
{
return;
}
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
if (node is ASTString)
{
sw.WriteLine("ASTString: " + ((ASTString)node).String.Replace("\n", "\\n"));
}
else if (node is ASTNumber)
{
sw.WriteLine("ASTNumber: " + ((ASTNumber)node).Number);
}
else if (node is ASTIdentifier)
{
sw.WriteLine("ASTIdentifier: " + ((ASTIdentifier)node).Identifier);
}
else if (node is ASTOperator)
{
ASTOperator op = (ASTOperator)node;
sw.WriteLine("ASTOperator: " + op.Operator);
PrintNode(op.Left, incident + 1);
PrintNode(op.Right, incident + 1);
}
else if (node is ASTStatement)
{
ASTStatement stm = (ASTStatement)node;
sw.WriteLine("ASTStatement: ");
PrintNode(stm.Statement, incident + 1);
}
else if (node is ASTFunctionCall)
{
ASTFunctionCall call = (ASTFunctionCall)node;
sw.WriteLine("ASTFunctionCall: " + call.Scope + "." + call.FunctionName);
foreach (ASTNode param in call.Parameter)
{
PrintNode(param, incident + 1);
}
}
else if (node is ASTClassParameter)
{
ASTClassParameter classP = (ASTClassParameter)node;
sw.WriteLine("ASTClassParameter: " + classP.Scope);
PrintNode(classP.Parameter, incident + 1);
}
else if (node is ASTIf)
{
ASTIf ifNode = (ASTIf)node;
sw.WriteLine("ASTIf:");
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCondition:");
PrintNode(ifNode.Condition, incident + 2);
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCodeBlock:");
foreach (ASTNode codeBlock in ifNode.CodeBlock)
{
PrintNode(codeBlock, incident + 2);
}
if (ifNode.ElseCodeBlock != null)
{
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tElse:");
foreach (ASTNode codeBlock in ifNode.ElseCodeBlock)
{
PrintNode(codeBlock, incident + 2);
}
}
}
else if (node is ASTFor)
{
ASTFor forNode = (ASTFor)node;
sw.WriteLine("ASTFor:");
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tInit:");
PrintNode(forNode.Initialise, incident + 2);
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCondition:");
PrintNode(forNode.Condition, incident + 2);
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCounter:");
PrintNode(forNode.Count, incident + 2);
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCodeBlock:");
foreach (ASTNode codeBlock in forNode.CodeBlock)
{
PrintNode(codeBlock, incident + 2);
}
}
else if (node is ASTWhile)
{
ASTWhile wNode = (ASTWhile)node;
sw.WriteLine("ASTWhile:");
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCondition:");
PrintNode(wNode.Condition, incident + 2);
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCodeBlock:");
foreach (ASTNode codeBlock in wNode.CodeBlock)
{
PrintNode(codeBlock, incident + 2);
}
}
else if (node is ASTFunction)
{
ASTFunction func = (ASTFunction)node;
if (node is ASTConstructor)
{
sw.WriteLine("ASTConstructor:");
}
else
{
sw.WriteLine("ASTFunction: " + func.ReturnValue.ToString() + " " + func.Name);
}
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tParameter:");
foreach (ASTNode n in func.Parameter)
{
PrintNode(n, incident + 2);
}
for (int i = 0; i < incident; i++)
{
sw.Write("\t");
}
sw.WriteLine("\tCodeBlock:");
foreach (ASTNode codeBlock in func.CodeBlock)
{
PrintNode(codeBlock, incident + 2);
}
}
else if (node is ASTFunctionParameter)
{
ASTFunctionParameter param = (ASTFunctionParameter)node;
switch (param.Type)
{
case VMType.Object:
sw.WriteLine("Object: " + param.Name);
break;
case VMType.String:
sw.WriteLine("String: " + param.Name);
break;
case VMType.Number:
sw.WriteLine("Number: " + param.Name);
break;
}
}
else if (node is ASTLocalVariable)
{
ASTLocalVariable param = (ASTLocalVariable)node;
switch (param.Type)
{
case VMType.Object:
sw.WriteLine("var Object: " + param.Name);
break;
case VMType.String:
sw.WriteLine("var String: " + param.Name);
break;
case VMType.Number:
sw.WriteLine("var Number: " + param.Name);
break;
}
}
else if (node is ASTReturn)
{
sw.WriteLine("ASTReturn:");
PrintNode(((ASTReturn)node).Return, incident + 1);
}
else if (node is ASTClass)
{
ASTClass cNode = (ASTClass)node;
sw.WriteLine("ASTClass: " + cNode.Name);
sw.WriteLine("\tAttributes:");
foreach (ASTNode n in cNode.Attributes)
{
PrintNode(n, incident + 2);
}
sw.WriteLine("\tConstructors:");
foreach (ASTNode n in cNode.Constructors)
{
PrintNode(n, incident + 2);
}
sw.WriteLine("\tFunctions:");
foreach (ASTNode n in cNode.Functions)
{
PrintNode(n, incident + 2);
}
}
}