private Token peek(int offset = 0)
{
if (i <= tokens.Count)
{
try
{
return(tokens[i + offset]);
}
catch { }
Tokens.Statement stat = new Tokens.Statement();
stat.Name = "";
return(stat);
}
else
{
Tokens.Statement stat = new Tokens.Statement();
stat.Name = "";
return(stat);
}
}
private Token read()
{
if (i <= tokens.Count)
{
try
{
return(tokens[i++]);
}
catch { }
Tokens.Statement stat = new Tokens.Statement();
stat.Name = "";
return(stat);
}
else
{
Tokens.Statement stat = new Tokens.Statement();
stat.Name = "";
return(stat);
}
}
private void doScan()
{
char val = (char)(byte)read();
while (peek() != -1)
{
while (char.IsWhiteSpace(val) || val == '\n')
{
if (val == '\n' || val == '\r' || val == Environment.NewLine[0])
{
if (ScanWhiteSpaces)
{
addToken(new Tokens.EOL());
}
this.lineNumber++;
}
val = (char)(byte)read();
}
if (peek() == -1)
{
break;
}
if (char.IsLetter(val))
{
StringBuilder sb = new StringBuilder();
while (char.IsLetterOrDigit(val) || val == '_')
{
sb.Append(val);
val = (char)(byte)read();
}
Tokens.Statement stmt = new Tokens.Statement();
stmt.Name = sb.ToString();
addToken(stmt);
}
else if (val == '/' && (char)(byte)peek() == '/')
{
while (val != '\n' && val != '\r')
{
val = (char)(byte)read();
}
}
else if (val == '0' && (char)(byte)peek() == 'x')
{
read();
val = (char)(byte)read();
StringBuilder sb = new StringBuilder();
while (char.IsDigit(val) || val.ToString().ToLower() == "a" || val.ToString().ToLower() == "b" || val.ToString().ToLower() == "c" || val.ToString().ToLower() == "d" || val.ToString().ToLower() == "e" || val.ToString().ToLower() == "f")
{
sb.Append(val);
val = (char)(byte)read();
}
Tokens.IntLiteral il = new Tokens.IntLiteral();
il.Value = Int32.Parse(sb.ToString(), System.Globalization.NumberStyles.HexNumber);
addToken(il);
}
else if (val == '\'')
{
Tokens.IntLiteral il = new Tokens.IntLiteral();
bool b = false;
if (((char)peek() == '\\'))
{
read();
if (((char)read()).ToString().ToLower()[0] == 'n')
{
il.Value = 10;
}
else if (((char)read()).ToString().ToLower()[0] == 'a')
{
il.Value = 7;
}
else if (((char)read()).ToString().ToLower()[0] == 'b')
{
il.Value = 8;
}
else if (((char)read()).ToString().ToLower()[0] == 'f')
{
il.Value = 12;
}
else if (((char)read()).ToString().ToLower()[0] == 'r')
{
il.Value = 13;
}
else if (((char)read()).ToString().ToLower()[0] == 't')
{
il.Value = 9;
}
else if (((char)read()).ToString().ToLower()[0] == 'v')
{
il.Value = 11;
}
else if (((char)read()).ToString().ToLower()[0] == '\'')
{
il.Value = 44;
}
else if (((char)read()).ToString().ToLower()[0] == '\"')
{
il.Value = 34;
}
b = true;
}
else
{
il.Value = read();
if (((char)read()) != '\'')
{
throw new Exception("Expected '");
}
}
if (b)
{
read();
}
b = false;
val = ((char)read());
this.tokens.Add(il);
}
else if (char.IsDigit(val) || (val == '-' && char.IsDigit((char)(byte)peek())))
{
StringBuilder sb = new StringBuilder();
while (char.IsDigit(val) || val == '.' || val == '-')
{
sb.Append(val);
val = (char)(byte)read();
}
if (sb.ToString().Contains(".") || ((char)peek()) == 'f')
{
if (((char)peek()) == 'f')
{
val = (char)(byte)read();
}
Tokens.FloatLiteral fl = new Tokens.FloatLiteral();
fl.Value = float.Parse(sb.ToString());
addToken(fl);
}
else
{
Tokens.IntLiteral il = new Tokens.IntLiteral();
il.Value = Convert.ToInt32(sb.ToString());
addToken(il);
}
}
else if (val == '"')
{
StringBuilder sb = new StringBuilder();
val = (char)(byte)read();
while (val != '"')
{
if (val == '\\')
{
char escape = (char)(byte)read();
if (escape == 'n')
{
sb.Append('\n');
}
else if (escape == '"')
{
sb.Append('"');
}
else if (escape == '\\')
{
sb.Append('\\');
}
else if (escape == '\'')
{
sb.Append('\'');
}
else if (escape == '0')
{
sb.Append('\0');
}
else if (escape == 'r')
{
sb.Append('\r');
}
}
else
{
sb.Append(val);
}
val = (char)(byte)read();
}
val = (char)(byte)read();
Tokens.StringLiteral sl = new Tokens.StringLiteral();
sl.Value = sb.ToString();
addToken(sl);
}
else
{
switch (val)
{
case '+':
if ((char)(byte)peek() == '+')
{
read();
addToken(new Tokens.Increment());
}
else if ((char)(byte)peek() == '=')
{
read();
addToken(new Tokens.PlusEquals());
}
else
{
addToken(new Tokens.Add());
}
break;
case '-':
if ((char)(byte)peek() == '-')
{
read();
addToken(new Tokens.Increment());
}
else if ((char)(byte)peek() == '>')
{
read();
addToken(new Tokens.ObjectReference());
}
else
{
addToken(new Tokens.Sub());
}
break;
case '|':
if (((char)peek()) == '|')
{
read();
addToken(new Tokens.BooleanOr());
}
else
{
addToken(new Tokens.Pipe());
}
break;
case '^':
if ((char)(byte)peek() == '=')
{
read();
addToken(new Tokens.PowEqual());
}
else
{
addToken(new Tokens.Pow());
};
break;
case '%':
addToken(new Tokens.Percent());
break;
case '?':
addToken(new Tokens.Question());
break;
case '/':
addToken(new Tokens.Div());
break;
case '*':
addToken(new Tokens.Mul());
break;
case ',':
addToken(new Tokens.Comma());
break;
case '.':
addToken(new Tokens.Dot());
break;
case ':':
addToken(new Tokens.Colon());
break;
case '#':
addToken(new Tokens.Hash());
break;
case '@':
addToken(new Tokens.At());
break;
case '>':
if ((char)(byte)peek() == '>')
{
read();
addToken(new Tokens.RightBitshift());
}
else
{
addToken(new Tokens.GreaterThan());
}
break;
case '<':
if ((char)(byte)peek() == '<')
{
read();
addToken(new Tokens.LeftBitshift());
}
else
{
addToken(new Tokens.LessThan());
}
break;
case ';':
addToken(new Tokens.SemiColon());
break;
case '{':
addToken(new Tokens.openCurlyBracket());
break;
case '}':
addToken(new Tokens.closeCurlyBracket());
break;
case '~':
addToken(new Tokens.Tilda());
break;
case '(':
addToken(new Tokens.openParenthesis());
break;
case ')':
addToken(new Tokens.closeParenthesis());
break;
case '[':
addToken(new Tokens.openBracket());
break;
case ']':
addToken(new Tokens.closeBracket());
break;
case '&':
if (char.IsLetter(((char)peek())))
{
string accum = "";
while (char.IsLetterOrDigit(((char)peek())) || ((char)peek()) == '_')
{
accum += ((char)read()).ToString();
}
Tokens.Dereference def = new Tokens.Dereference();
def.Name = accum;
addToken(def);
}
else if ((char)(byte)peek() == '&')
{
read();
addToken(new Tokens.BooleanAnd());
}
else
{
addToken(new Tokens.And());
}
break;
case '!':
if ((char)(byte)peek() == '=')
{
read();
addToken(new Tokens.NotEqual());
}
else
{
addToken(new Tokens.Exclamation());
}
break;
case '=':
if (!((char)(byte)peek() == '='))
{
addToken(new Tokens.Assign());
}
else
{
read();
addToken(new Tokens.Equal());
}
break;
case '_':
addToken(new Tokens.Underline());
break;
case '$':
addToken(new Tokens.Dollah());
break;
default:
throw new Exception("Lexer encountered an unexepected character '" + val + "'");
}
if (peek() != -1)
{
val = (char)(byte)read();
}
}
}
}