public static bool CheckBounds(Token[] tokens, int i)
{
if (i >= tokens.Length)
{
throw new ParserException("Unexpected end of stream.", i, tokens[i]);
}
return true;
}
public static Token Expect(Token[] tokens, ref int i, TokenType type)
{
if (tokens[i].Type != type) //Throw exception if token type does not match expected
{
throw new ParserException(string.Format("Expected token of type {0}.", type.ToString()), i, tokens[i]);
}
else //Consume token
{
Token t = tokens[i];
i++;
return t;
}
}
static Token ProcessMinus(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '-') //--
{
Token t = new Token(raw.Substring(i, 2), TokenType.DoubleMinus);
i += 2;
return t;
}
else if (raw.Length > i + 1 && raw[i + 1] == '=') //-=
{
Token t = new Token(raw.Substring(i, 2), TokenType.MinusEquals);
i += 2;
return t;
}
else if (raw.Length > i + 1 && raw[i + 1] == '>') //->
{
Token t = new Token(raw.Substring(i, 2), TokenType.Arrow);
i += 2;
return t;
}
else //-
{
Token t = new Token(raw[i].ToString(), TokenType.Minus);
i += 1;
return t;
}
}
static Token ProcessLess(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //Token is '<='
{
Token t = new Token(raw.Substring(i, 2), TokenType.LessThanEqual);
i += 2;
return t;
}
else if (raw.Length > i + 2 && raw.Substring(i, 3) == "<<=") //<<=
{
Token t = new Token(raw.Substring(i, 3), TokenType.ShiftLeftEqual);
i += 3;
return t;
}
else if (raw.Length > i + 1 && raw.Substring(i, 2) == "<<")//<<
{
Token t = new Token(raw.Substring(i, 2), TokenType.ShiftLeft);
i += 2;
return t;
}
else //Token is '<'
{
Token t = new Token(raw[i].ToString(), TokenType.LessThan);
i += 1;
return t;
}
}
static Token ProcessGreater(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //Token is '>='
{
Token t = new Token(raw.Substring(i, 2), TokenType.GreaterThanEqual);
i += 2;
return t;
}
else if (raw.Length > i + 2 && raw.Substring(i, 3) == ">>=") //>>=
{
Token t = new Token(raw.Substring(i, 3), TokenType.ShiftRightEqual);
i += 3;
return t;
}
else if (raw.Length > i + 1 && raw.Substring(i, 2) == ">>")//>>
{
Token t = new Token(raw.Substring(i, 2), TokenType.ShiftRight);
i += 2;
return t;
}
else //Token is '>'
{
Token t = new Token(raw[i].ToString(), TokenType.GreaterThan);
i += 1;
return t;
}
}
static Token ProcessExclamation(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //Token is '!='
{
Token t = new Token(raw.Substring(i, 2), TokenType.NotEqual);
i += 2;
return t;
}
else //Token is '!'
{
Token t = new Token(raw[i].ToString(), TokenType.Exclamation);
i += 1;
return t;
}
}
public static bool Check(Token[] tokens, int i, TokenType type)
{
return tokens[i].Type == type;
}
static Token ProcessAmpersand(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //&=
{
Token t = new Token(raw.Substring(i, 2), TokenType.AmpersandEqual);
i += 2;
return t;
}
else if (raw.Length > i + 1 && raw[i + 1] == '&') //&&
{
Token t = new Token(raw.Substring(i, 2), TokenType.DoubleAmpersand);
i += 2;
return t;
}
else //&
{
Token t = new Token(raw[i].ToString(), TokenType.Ampersand);
i += 1;
return t;
}
}
static Token ProcessStar(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //*=
{
Token t = new Token(raw.Substring(i, 2), TokenType.StarEqual);
i += 2;
return t;
}
else //*
{
Token t = new Token(raw[i].ToString(), TokenType.Star);
i += 1;
return t;
}
}
static Token ProcessCaret(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //^=
{
Token t = new Token(raw.Substring(i, 2), TokenType.CaretEqual);
i += 2;
return t;
}
else //^
{
Token t = new Token(raw[i].ToString(), TokenType.Caret);
i += 1;
return t;
}
}
internal static Token Peek(Token[] tokens, int i)
{
return tokens[i];
}
public static bool CheckBoundsNoThrow(Token[] tokens, int i)
{
return (i < tokens.Length);
}
public static bool CheckLiteral(Token[] tokens, int i, TokenType type, IEnumerable<string> literals)
{
return (tokens[i].Type == type) && literals.Contains(tokens[i].Literal);
}
public static bool CheckLiteral(Token[] tokens, int i, TokenType type, string literal)
{
return (tokens[i].Type == type) && (tokens[i].Literal == literal);
}
static Token ProcessPipe(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '|') //||
{
Token t = new Token(raw.Substring(i, 2), TokenType.DoublePipe);
i += 2;
return t;
}
else if (raw.Length > i + 1 && raw[i + 1] == '=') //|=
{
Token t = new Token(raw.Substring(i, 2), TokenType.PipeEqual);
i += 2;
return t;
}
else //|
{
Token t = new Token(raw[i].ToString(), TokenType.Pipe);
i += 1;
return t;
}
}
static Token ProcessDivide(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') // /=
{
Token t = new Token(raw.Substring(i, 2), TokenType.DivideEqual);
i += 2;
return t;
}
else // /
{
Token t = new Token(raw[i].ToString(), TokenType.Divide);
i += 1;
return t;
}
}
static Token ProcessPlus(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '+') //++
{
Token t = new Token(raw.Substring(i, 2), TokenType.DoublePlus);
i += 2;
return t;
}
else if (raw.Length > i + 1 && raw[i + 1] == '=') //+=
{
Token t = new Token(raw.Substring(i, 2), TokenType.PlusEqual);
i += 2;
return t;
}
else //+
{
Token t = new Token(raw[i].ToString(), TokenType.Plus);
i += 1;
return t;
}
}
static Token ProcessDot(string raw, ref int i)
{
if (raw.Length > i + 1 && char.IsNumber(raw[i + 1])) //Float literal
{
int literalStart = i;
i += 1; //Skip over '.'
for (; i < raw.Length && char.IsNumber(raw[i]); i++) ;
return new Token(raw.Substring(literalStart, i - literalStart), TokenType.Float);
}
else //Dot
{
Token t = new Token(raw[i].ToString(), TokenType.Dot);
i += 1;
return t;
}
}
static Token ProcessTilde(string raw, ref int i)
{
Token t = new Token(raw[i].ToString(), TokenType.Tilde);
i += 1;
return t;
}
static Token ProcessEqual(string raw, ref int i)
{
if (raw.Length > i + 1 && raw[i + 1] == '=') //Token is '=='
{
Token t = new Token(raw.Substring(i, 2), TokenType.DoubleEqual);
i += 2;
return t;
}
else //Token is '='
{
Token t = new Token(raw[i].ToString(), TokenType.Equal);
i += 1;
return t;
}
}
public TokenStream(Token[] tokens)
{
_index = 0;
_tokens = tokens;
}
public ParserException(string message, int tokenIndex, Token token) : base(message)
{
TokenIndex = tokenIndex;
Token = token;
}