private AstItem ReadStatement(TokenIterator tokens)
{
AstItem result = null;
var token = tokens.Current();
tokens.StartCapture();
switch (token.Kind)
{
case TokenKind.Let:
result = ReadVarDecl(tokens);
break;
case TokenKind.Ret:
//Pop "ret"
tokens.Pop();
var current = tokens.Current();
DataType valueType = DataType.VOID;
AstItem valueExpression = null;
if (current.Kind != TokenKind.SemiColon)
{
valueExpression = ReadExpression(tokens, TokenKind.SemiColon);
valueType = valueExpression.DataType;
}
result = AstItem.Return(valueType, valueExpression);
tokens.PopExpected(TokenKind.SemiColon);
break;
case TokenKind.Word:
var next = tokens.Next();
if (next.Kind == TokenKind.RoundBracketOpen)
{
result = ReadFuncCall(tokens);
tokens.PopExpected(TokenKind.SemiColon);
}
else if (next.Kind == TokenKind.AssigmnentOperator)
{
result = ReadVariableAssignment(tokens);
}
else if (next.Kind == TokenKind.SquareBracketOpen)
{
result = ReadIndexerAssignment(tokens);
}
else
{
throw new Exception("Unexpected token after identifier '" + token.Value + "'. Expected '=' or '(', found: " + next);
}
break;
case TokenKind.If:
result = ReadIfStatement(tokens);
break;
case TokenKind.Del:
result = ReadDelStatement(tokens);
tokens.PopExpected(TokenKind.SemiColon);
break;
case TokenKind.ExpressionOperator:
if (token.Value == "*")
{
result = ReadPointerAssignment(tokens);
}
else
{
throw new Exception("Unexpected token. Expected 'let', 'ret', '}' or identifier, found: " + token);
}
break;
case TokenKind.For:
result = ReadForLoop(tokens);
break;
case TokenKind.While:
result = ReadWhileLoop(tokens);
break;
case TokenKind.Break:
result = ReadBreak(tokens);
break;
case TokenKind.CurlyBracketClose:
//End of function
return(null);
default:
throw new Exception("Unexpected token. Expected 'let', 'ret', '}' or identifier, found: " + token);
}
var lineTokens = tokens.GetCapture();
if (lineTokens.Count > 0)
{
result.SourceLine = String.Join(" ", lineTokens.ConvertAll <string>((a) => a.Value));
}
return(result);
}