private void UpdateTokenState(AsciiAtom command)
{
if (command.Category != AtomType.CONTROL &&
command.Category != AtomType.DELIMITER)
{
this.currentToken = this.currentToken + command.Symbol;
}
else if (this.CurrentState == LexicalMachineState.QUOTED_STRING_TOKEN)
{
this.currentToken = this.currentToken + command.Symbol;
}
}
public void MoveNext(AsciiAtom command)
{
LexicalMachineState nextState = GetNext(command.Category);
if (nextState == LexicalMachineState.ARRAY_TOKEN && this.CurrentState == LexicalMachineState.VAR_TOKEN)
{
this.arrayToken = this.currentToken;
this.ClearToken();
this.CurrentState = nextState;
return;
}
else if (this.CurrentState == LexicalMachineState.INDEX_OF_ARRAY_TOKEN && command.Category != AtomType.DIGIT)
{
this.indexOrSize = int.Parse(this.currentToken);
this.ClearToken();
this.OnTokenIdentified(command);
this.CurrentState = nextState;
return;
}
else if (nextState == LexicalMachineState.VAR_TOKEN && this.CurrentState == LexicalMachineState.EMPTY)
{
this.UpdateTokenState(command);
this.CurrentState = nextState;
return;
}
else if (nextState == LexicalMachineState.EMPTY && this.CurrentState == LexicalMachineState.VAR_TOKEN ||
nextState == LexicalMachineState.EMPTY && this.CurrentState == LexicalMachineState.QUOTED_STRING_TOKEN)
{
this.UpdateTokenState(command);
this.OnTokenIdentified(command);
this.ClearToken();
this.CurrentState = nextState;
return;
}
else if (nextState == LexicalMachineState.EMPTY && command.Category == AtomType.CONTROL ||
nextState == LexicalMachineState.EMPTY && this.CurrentState != LexicalMachineState.EMPTY ||
nextState == LexicalMachineState.SPECIAL_TOKEN &&
(this.CurrentState == LexicalMachineState.STRING_TOKEN || this.CurrentState == LexicalMachineState.INT_TOKEN || this.CurrentState == LexicalMachineState.SPECIAL_TOKEN) ||
this.CurrentState == LexicalMachineState.SPECIAL_TOKEN &&
(nextState == LexicalMachineState.INT_TOKEN || nextState == LexicalMachineState.STRING_TOKEN))
{
this.OnTokenIdentified(command);
this.ClearToken();
}
this.UpdateTokenState(command);
this.CurrentState = nextState;
}
protected virtual void OnTokenIdentified(AsciiAtom command)
{
if (this.CurrentState == LexicalMachineState.INDEX_OF_ARRAY_TOKEN)
{
NotifyTokenIdentified?.Invoke(new Token(this.arrayToken, this.indexOrSize, false));
}
else if (command.Category == AtomType.CONTROL)
{
NotifyTokenIdentified?.Invoke(new Token(this.CurrentState, this.currentToken, command));
NotifyTokenIdentified?.Invoke(new Token());
}
else
{
Console.WriteLine("Lexical: sent token: " + this.currentToken);
NotifyTokenIdentified?.Invoke(new Token(this.CurrentState, this.currentToken, command));
}
}
public Token(LexicalMachineState state, string tokenString, AsciiAtom command)
{
this.Text = tokenString;
if (state == LexicalMachineState.STRING_TOKEN)
{
this.Type = this.Text.ToUpper() switch
{
"PRINT" => TokenType.PRINT,
"DIM" => TokenType.DIM,
"LET" => TokenType.LET,
"READ" => TokenType.READ,
"DATA" => TokenType.DATA,
"FOR" => TokenType.FOR,
"TO" => TokenType.TO,
"NEXT" => TokenType.NEXT,
"GO" => TokenType.GO,
"GOTO" => TokenType.GOTO,
"GOSUB" => TokenType.GOSUB,
"RETURN" => TokenType.RETURN,
"REM" => TokenType.REMARK,
"IF" => TokenType.IF,
"STEP" => TokenType.STEP,
"THEN" => TokenType.THEN,
"END" => TokenType.FINAL,
_ => TokenType.STRING
};
}
else if (state == LexicalMachineState.INT_TOKEN)
{
this.Type = TokenType.INT;
}
else if (state == LexicalMachineState.SPECIAL_TOKEN)
{
this.Type = this.Text switch
{
"=" => TokenType.EQUALS,
":=" => TokenType.EQUALS,
">" => TokenType.GREATER,
">=" => TokenType.GREATER_OR_EQUAL,
"<" => TokenType.LESS,
"<=" => TokenType.LESS_OR_EQUAL,
"<>" => TokenType.NOT_EQUAL,
"(" => TokenType.OPENING_BRACES,
")" => TokenType.CLOSING_BRACES,
"," => TokenType.COMMA,
"+" => TokenType.PLUS,
"-" => TokenType.MINUS,
"*" => TokenType.MULT,
"/" => TokenType.DIV,
_ => TokenType.ERROR
};
}
else if (state == LexicalMachineState.VAR_TOKEN)
{
this.Type = TokenType.VAR;
}
else if (state == LexicalMachineState.QUOTED_STRING_TOKEN)
{
this.Type = TokenType.QUOTED_STRING;
}
else if (command.Category == AtomType.CONTROL)
{
this.Type = TokenType.END;
}
else
{
this.Type = TokenType.ERROR;
}
}
public void ConsumeCategorizedSymbolEvent(AsciiAtom symbol)
{
this.MoveNext(symbol);
}
