private StatementNode ParseStatement(Token initialToken)
{
if (initialToken.TokenType == Tokens.EndOfLine)
return null;
if (initialToken.TokenType == Tokens.Identifier)
{
StatementNode statement = new StatementNode();
var instructionTokens = new List<Token>();
Token t = _lex.GetNextToken();
if (t.TokenType == Tokens.Colon)
{
statement.Label = initialToken.SourceText;
t = _lex.GetNextToken();
}
else
{
instructionTokens.Add(initialToken);
}
while (t.TokenType != Tokens.EndOfLine)
{
instructionTokens.Add(t);
t = _lex.GetNextToken();
}
ParseInstruction(statement, instructionTokens);
return statement;
}
throw new UnexprectedTokenException(String.Format("Unexprected token: {0}", initialToken));
}
private void ParseInstruction(StatementNode statement, IList<Token> instructionTokens)
{
if (instructionTokens[0].TokenType != Tokens.Identifier)
throw new UnexprectedTokenException(String.Format("Unexprected token: {0}", instructionTokens[0]));
statement.Mnemonic = instructionTokens[0].SourceText;
instructionTokens.RemoveAt(0);
if (instructionTokens.Count() > 0)
ParseParameterList(statement, instructionTokens);
}
private void ParseParameterList(StatementNode statement, IList<Token> parameterListTokens)
{
statement.Parameters.Add(ParseParemeter(parameterListTokens[0]));
if (parameterListTokens.Count() > 1)
{
if (parameterListTokens[1].TokenType != Tokens.Comma)
throw new UnexprectedTokenException(String.Format("Unexprected token: {0}", parameterListTokens[1]));
statement.Parameters.Add(ParseParemeter(parameterListTokens[2]));
}
if (parameterListTokens.Count() != 1 && parameterListTokens.Count() != 3)
throw new ApplicationException("Unexpected parameter list.");
}