public List <Token> Parse(string filepath)
{
StreamReader input = new StreamReader(filepath);
Cursor cursor = new Cursor(input);
List <Token> tokens = new List <Token>();
Token token;
State state = State.ProceedToNextStatement;
LexicalError err = LexicalError.None;
uint line = 1;
uint skippedLines = 0;
while (true)
{
switch (state)
{
case State.ProceedToNextStatement:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
Parser.SkipEmptyLines(cursor, ref err, ref skippedLines);
line += skippedLines;
if (err != LexicalError.None)
{
state = State.Error;
}
else
{
state = State.ProceedToNextToken;
}
break;
case State.ProceedToNextToken:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
Parser.SkipSpaces(cursor);
if (Utils.IsLetter(cursor.CurrChar()))
{
state = State.Identifier;
}
else if (Utils.IsDigit(cursor.CurrChar()))
{
state = State.Number;
}
else if (Utils.IsQuote(cursor.CurrChar()))
{
state = State.String;
}
else if (Utils.IsSymbol(cursor.CurrChar()))
{
state = State.Symbol;
}
else if (Utils.IsNewLine(cursor.CurrChar()))
{
state = State.EndOfStatement;
}
else if (Utils.IsZeroChar(cursor.CurrChar()))
{
state = State.Final;
}
else
{
err = LexicalError.UnexpectedChar;
state = State.Error;
}
break;
case State.Identifier:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
token = Parser.ProcessIdentifier(cursor, ref err);
if (err != LexicalError.None)
{
state = State.Error;
}
else
{
tokens.Add(token);
state = State.ProceedToNextToken;
}
break;
case State.Number:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
token = Parser.ProcessNumber(cursor, ref err);
if (err != LexicalError.None)
{
state = State.Error;
}
else
{
tokens.Add(token);
state = State.ProceedToNextToken;
}
break;
case State.String:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
token = Parser.ProcessString(cursor, ref err);
if (err != LexicalError.None)
{
state = State.Error;
}
else
{
tokens.Add(token);
state = State.ProceedToNextToken;
}
break;
case State.Symbol:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
token = Parser.ProcessSymbol(cursor, ref err);
if (err != LexicalError.None)
{
state = State.Error;
}
else
{
tokens.Add(token);
state = State.ProceedToNextToken;
}
break;
case State.EndOfStatement:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
token = Parser.ProcessEndOfStatement(cursor, ref err, ref skippedLines);
line += skippedLines;
if (err != LexicalError.None)
{
state = State.Error;
}
else
{
tokens.Add(token);
state = State.ProceedToNextStatement;
}
break;
case State.Final:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
// maybe this will change
if (tokens[tokens.Count - 1].Type != TokenType.EndOfStatement)
{
tokens.Add(new Token(TokenType.EndOfStatement, ""));
}
Console.WriteLine("Lexical Parsing success!");
/*
* for (Token t in tokens)
* {
* Console.WriteLine(t.ToString());
* }
*/
input.Close();
return(tokens);
//break;
case State.Error:
#if DBG_SHIFTING_STATE
Console.WriteLine("dbg: Entering state " + state.ToString());
#endif
Console.WriteLine("Error: " + err.ToString() + " at line(" + line + ")");
input.Close();
return(null);
//break;
}
}
}
