2004-08-04 Anirban Bhattacharjee <banirban@novell.com>
[mono.git] / mcs / mbas / mb-tokenizer.cs
index 8c03717a7e56ebf23703739fce6f57459cb987e6..e37b732e1a80909415b3d5cd19e16325e8dd6244 100644 (file)
-//\r
-// Mono.MonoBASIC.Tokenizer.cs: The Tokenizer for the MonoBASIC compiler\r
-//\r
-// Author: A Rafael D Teixeira (rafaelteixeirabr@hotmail.com)\r
-//        \r
-// Based on cs-tokenizer.cs by Miguel de Icaza (miguel@gnu.org)\r
-//\r
-// Licensed under the terms of the GNU GPL\r
-//\r
-// Copyright (C) 2001 A Rafael D Teixeira\r
-//\r
-\r
-namespace Mono.MonoBASIC\r
-{\r
-       using System;\r
-       using System.Text;\r
-       using System.Collections;\r
-       using System.IO;\r
-       using System.Globalization;\r
-       using Mono.Languages;\r
-       using Mono.CSharp;\r
-       \r
-       /// <summary>\r
-       ///    Tokenizer for MonoBASIC source code. \r
-       /// </summary>\r
-       \r
-       public class Tokenizer : yyParser.yyInput\r
-       {\r
-               TextReader reader;\r
-               // TODO: public SourceFile file_name;\r
-               public string file_name;\r
-               public string ref_name;\r
-               public int ref_line = 1;\r
-               public int line = 1;\r
-               public int col = 1;\r
-               public int current_token = Token.EOL;\r
-               bool handle_get_set = false;\r
-\r
-               public int ExpandedTabsSize = 4; \r
-\r
-               public string location {\r
-                       get {\r
-                               string det;\r
-\r
-                               if (current_token == Token.ERROR)\r
-                                       det = "detail: " + error_details;\r
-                               else\r
-                                       det = "";\r
-                               \r
-                               return "Line:     "+line+" Col: "+col + "\n" +\r
-                                      "VirtLine: "+ref_line +\r
-                                      " Token: "+current_token + " " + det;\r
-                       }\r
-               }\r
-\r
-               public bool properties {\r
-                       get {\r
-                               return handle_get_set;\r
-                       }\r
-\r
-                       set {\r
-                               handle_get_set = value;\r
-                       }\r
-                }\r
-               \r
-               //\r
-               // Class variables\r
-               // \r
-               static Hashtable keywords;\r
-               static NumberStyles styles;\r
-               static NumberFormatInfo csharp_format_info;\r
-               \r
-               //\r
-               // Pre-processor\r
-               //\r
-               Hashtable defines;\r
-\r
-               const int TAKING        = 1;\r
-               const int TAKEN_BEFORE  = 2;\r
-               const int ELSE_SEEN     = 4;\r
-               const int PARENT_TAKING = 8;\r
-               const int REGION        = 16;           \r
-\r
-               //\r
-               // pre-processor if stack state:\r
-               //\r
-               Stack ifstack;\r
-\r
-               //\r
-               // Values for the associated token returned\r
-               //\r
-               System.Text.StringBuilder number;\r
-               int putback_char;\r
-               Object val;\r
-               \r
-               //\r
-               // Details about the error encoutered by the tokenizer\r
-               //\r
-               string error_details;\r
-               \r
-               public string error {\r
-                       get {\r
-                               return error_details;\r
-                       }\r
-               }\r
-               \r
-               public int Line {\r
-                       get {\r
-                               return line;\r
-                       }\r
-               }\r
-\r
-               public int Col {\r
-                       get {\r
-                               return col;\r
-                       }\r
-               }\r
-               \r
-               static void initTokens ()\r
-               {\r
-                       keywords = new Hashtable ();\r
-\r
-                       keywords.Add ("addhandler", Token.ADDHANDLER);\r
-                       keywords.Add ("addressof", Token.ADDRESSOF);\r
-                       keywords.Add ("alias", Token.ALIAS);\r
-                       keywords.Add ("and", Token.AND);\r
-                       keywords.Add ("andalso", Token.ANDALSO);\r
-                       keywords.Add ("ansi", Token.ANSI);\r
-                       keywords.Add ("as", Token.AS);\r
-                       keywords.Add ("assembly", Token.ASSEMBLY);\r
-                       keywords.Add ("auto", Token.AUTO);\r
-                       keywords.Add ("binary", Token.BINARY);\r
-                       keywords.Add ("boolean", Token.BOOLEAN);\r
-                       keywords.Add ("byref", Token.BYREF);\r
-                       keywords.Add ("byte", Token.BYTE);\r
-                       keywords.Add ("byval", Token.BYVAL);\r
-                       keywords.Add ("call", Token.CALL);\r
-                       keywords.Add ("case", Token.CASE);\r
-                       keywords.Add ("catch", Token.CATCH);\r
-                       keywords.Add ("cbool", Token.CBOOL);\r
-                       keywords.Add ("cbyte", Token.CBYTE);\r
-                       keywords.Add ("cchar", Token.CCHAR);\r
-                       keywords.Add ("cdate", Token.CDATE);\r
-                       keywords.Add ("cdec", Token.CDEC);\r
-                       keywords.Add ("cdbl", Token.CDBL);\r
-                       keywords.Add ("char", Token.CHAR);\r
-                       keywords.Add ("cint", Token.CINT);\r
-                       keywords.Add ("class", Token.CLASS);\r
-                       keywords.Add ("clng", Token.CLNG);\r
-                       keywords.Add ("cobj", Token.COBJ);\r
-                       keywords.Add ("compare", Token.COMPARE);\r
-                       keywords.Add ("const", Token.CONST);\r
-                       keywords.Add ("cshort", Token.CSHORT);\r
-                       keywords.Add ("csng", Token.CSNG);\r
-                       keywords.Add ("cstr", Token.CSTR);\r
-                       keywords.Add ("ctype", Token.CTYPE);\r
-                       //keywords.Add ("date", Token.DATE);\r
-                       keywords.Add ("decimal", Token.DECIMAL);\r
-                       keywords.Add ("declare", Token.DECLARE);\r
-                       keywords.Add ("default", Token.DEFAULT);\r
-                       keywords.Add ("delegate", Token.DELEGATE);\r
-                       keywords.Add ("dim", Token.DIM);\r
-                       keywords.Add ("do", Token.DO);\r
-                       keywords.Add ("double", Token.DOUBLE);\r
-                       keywords.Add ("each", Token.EACH);\r
-                       keywords.Add ("else", Token.ELSE);\r
-                       keywords.Add ("elseif", Token.ELSEIF);\r
-                       keywords.Add ("end", Token.END);\r
-                       keywords.Add ("enum", Token.ENUM);\r
-                       keywords.Add ("erase", Token.ERASE);\r
-                       keywords.Add ("error", Token.ERROR);\r
-                       keywords.Add ("event", Token.EVENT);\r
-                       keywords.Add ("exit", Token.EXIT);\r
-                       keywords.Add ("explicit", Token.EXPLICIT);\r
-                       keywords.Add ("false", Token.FALSE);\r
-                       keywords.Add ("finally", Token.FINALLY);\r
-                       keywords.Add ("for", Token.FOR);\r
-                       keywords.Add ("friend", Token.FRIEND);\r
-                       keywords.Add ("function", Token.FUNCTION);\r
-                       keywords.Add ("get", Token.GET);\r
-                       //keywords.Add ("gettype", Token.GETTYPE);\r
-                       keywords.Add ("goto", Token.GOTO);\r
-                       keywords.Add ("handles", Token.HANDLES);\r
-                       keywords.Add ("if", Token.IF);\r
-                       keywords.Add ("implements", Token.IMPLEMENTS);\r
-                       keywords.Add ("imports", Token.IMPORTS);\r
-                       keywords.Add ("in", Token.IN);\r
-                       keywords.Add ("inherits", Token.INHERITS);\r
-                       keywords.Add ("integer", Token.INTEGER);\r
-                       keywords.Add ("interface", Token.INTERFACE);\r
-                       keywords.Add ("is", Token.IS);\r
-                       keywords.Add ("let ", Token.LET );\r
-                       keywords.Add ("lib ", Token.LIB );\r
-                       keywords.Add ("like ", Token.LIKE );\r
-                       keywords.Add ("long", Token.LONG);\r
-                       keywords.Add ("loop", Token.LOOP);\r
-                       keywords.Add ("me", Token.ME);\r
-                       keywords.Add ("mod", Token.MOD);\r
-                       keywords.Add ("module", Token.MODULE);\r
-                       keywords.Add ("mustinherit", Token.MUSTINHERIT);\r
-                       keywords.Add ("mustoverride", Token.MUSTOVERRIDE);\r
-                       keywords.Add ("mybase", Token.MYBASE);\r
-                       keywords.Add ("myclass", Token.MYCLASS);\r
-                       keywords.Add ("namespace", Token.NAMESPACE);\r
-                       keywords.Add ("new", Token.NEW);\r
-                       keywords.Add ("next", Token.NEXT);\r
-                       keywords.Add ("not", Token.NOT);\r
-                       keywords.Add ("nothing", Token.NOTHING);\r
-                       keywords.Add ("notinheritable", Token.NOTINHERITABLE);\r
-                       keywords.Add ("notoverridable", Token.NOTOVERRIDABLE);\r
-                       keywords.Add ("object", Token.OBJECT);\r
-                       keywords.Add ("off", Token.OFF);\r
-                       keywords.Add ("on", Token.ON);\r
-                       keywords.Add ("option", Token.OPTION);\r
-                       keywords.Add ("optional", Token.OPTIONAL);\r
-                       keywords.Add ("or", Token.OR);\r
-                       keywords.Add ("orelse", Token.ORELSE);\r
-                       keywords.Add ("overloads", Token.OVERLOADS);\r
-                       keywords.Add ("overridable", Token.OVERRIDABLE);\r
-                       keywords.Add ("overrides", Token.OVERRIDES);\r
-                       keywords.Add ("paramarray", Token.PARAM_ARRAY);\r
-                       keywords.Add ("preserve", Token.PRESERVE);\r
-                       keywords.Add ("private", Token.PRIVATE);\r
-                       keywords.Add ("property", Token.PROPERTY);\r
-                       keywords.Add ("protected", Token.PROTECTED);\r
-                       keywords.Add ("public", Token.PUBLIC);\r
-                       keywords.Add ("raiseevent", Token.RAISEEVENT);\r
-                       keywords.Add ("readonly", Token.READONLY);\r
-                       keywords.Add ("redim", Token.REDIM);\r
-                       keywords.Add ("rem", Token.REM);\r
-                       keywords.Add ("removehandler", Token.REMOVEHANDLER);\r
-                       keywords.Add ("resume", Token.RESUME);\r
-                       keywords.Add ("return", Token.RETURN);\r
-                       keywords.Add ("select", Token.SELECT);\r
-                       keywords.Add ("set", Token.SET);\r
-                       keywords.Add ("shadows", Token.SHADOWS);\r
-                       keywords.Add ("shared", Token.SHARED);\r
-                       keywords.Add ("short", Token.SHORT);\r
-                       keywords.Add ("single", Token.SINGLE);\r
-                       keywords.Add ("sizeof", Token.SIZEOF);\r
-                       keywords.Add ("static", Token.STATIC);\r
-                       keywords.Add ("step", Token.STEP);\r
-                       keywords.Add ("stop", Token.STOP);\r
-                       keywords.Add ("strict", Token.STRICT);\r
-                       keywords.Add ("string", Token.STRING);\r
-                       keywords.Add ("structure", Token.STRUCTURE);\r
-                       keywords.Add ("sub", Token.SUB);\r
-                       keywords.Add ("synclock", Token.SYNCLOCK);\r
-                       keywords.Add ("text", Token.TEXT);\r
-                       keywords.Add ("then", Token.THEN);\r
-                       keywords.Add ("throw", Token.THROW);\r
-                       keywords.Add ("to", Token.TO);\r
-                       keywords.Add ("true", Token.TRUE);\r
-                       keywords.Add ("try", Token.TRY);\r
-                       keywords.Add ("typeof", Token.TYPEOF);\r
-                       keywords.Add ("unicode", Token.UNICODE);\r
-                       keywords.Add ("until", Token.UNTIL);\r
-                       keywords.Add ("variant", Token.VARIANT);\r
-                       keywords.Add ("when", Token.WHEN);\r
-                       keywords.Add ("while", Token.WHILE);\r
-                       keywords.Add ("with", Token.WITH);\r
-                       keywords.Add ("withevents", Token.WITHEVENTS);\r
-                       keywords.Add ("writeonly", Token.WRITEONLY);\r
-                       keywords.Add ("xor", Token.XOR);\r
-\r
-                       if (Parser.UseExtendedSyntax){\r
-                               keywords.Add ("yield", Token.YIELD);\r
-                       }\r
-\r
-               }\r
-\r
-               //\r
-               // Class initializer\r
-               // \r
-               static Tokenizer ()\r
-               {\r
-                       initTokens ();\r
-                       csharp_format_info = new NumberFormatInfo ();\r
-                       csharp_format_info.CurrencyDecimalSeparator = ".";\r
-                       styles = NumberStyles.AllowExponent | NumberStyles.AllowDecimalPoint;\r
-               }\r
-\r
-               bool is_keyword (string name)\r
-               {\r
-                       bool res;\r
-\r
-                       res = keywords.Contains(name.ToLower());\r
-                       if ((name == "get" || name == "set") && handle_get_set == false)\r
-                               return false;\r
-                       return res;\r
-               }\r
-\r
-               int getKeyword (string name)\r
-               {\r
-                       return (int) (keywords [name.ToLower()]);\r
-               }\r
-               \r
-               public Location Location {\r
-                       get {\r
-                               return new Location (ref_line);\r
-                       }\r
-               }\r
-               \r
-               void define (string def)\r
-               {\r
-                       if (!RootContext.AllDefines.Contains(def)){\r
-                               RootContext.AllDefines [def] = true;\r
-                       }\r
-                       if (defines.Contains (def))\r
-                               return;\r
-                       defines [def] = true;\r
-               }\r
-\r
-               public bool PropertyParsing {\r
-                       get {\r
-                               return handle_get_set;\r
-                       }\r
-\r
-                       set {\r
-                               handle_get_set = value;\r
-                       }\r
-                }\r
-                               \r
-               bool is_identifier_start_character (char c)\r
-               {\r
-                       return Char.IsLetter (c) || c == '_' ;\r
-               }\r
-\r
-               bool is_identifier_part_character (char c)\r
-               {\r
-                       return (Char.IsLetter (c) || Char.IsDigit (c) || c == '_');\r
-               }\r
-\r
-               int is_punct (char c, ref bool doread)\r
-               {\r
-                       int idx = "{}[](),:;~+-*/%&|^!=<>?".IndexOf (c);\r
-                       int d;\r
-                       int t;\r
-\r
-                       doread = false;\r
-\r
-                       switch (c){\r
-                       case '[':\r
-                               return Token.OPEN_BRACKET;\r
-                       case ']':\r
-                               return Token.CLOSE_BRACKET;\r
-                       case '{':\r
-                               return Token.OPEN_BRACE;\r
-                       case '}':\r
-                               return Token.CLOSE_BRACE;                               \r
-                       case '(':\r
-                               return Token.OPEN_PARENS;\r
-                       case ')':\r
-                               return Token.CLOSE_PARENS;\r
-                       case ',':\r
-                               return Token.COMMA;\r
-                       //case ':':\r
-                       //      return Token.COLON;\r
-                       case '?':\r
-                               return Token.INTERR;\r
-                       //case '&':\r
-                       //      return Token.OP_CONCAT;                         \r
-                       }\r
-\r
-                       d = peekChar ();\r
-                       if (c == '+'){\r
-                               \r
-                               if (d == '+')\r
-                                       t = Token.OP_INC;\r
-                               else if (d == '=')\r
-                                       t = Token.OP_ADD_ASSIGN;\r
-                               else\r
-                                       return Token.PLUS;\r
-                               doread = true;\r
-                               return t;\r
-                       }\r
-                       if (c == '&'){\r
-                               if (d == '=')\r
-                                       t = Token.OP_CONCAT_ASSIGN;\r
-                               else\r
-                                       return Token.OP_CONCAT;\r
-                               doread = true;\r
-                               return t;\r
-                       }                       \r
-                       if (c == '-'){\r
-                               if (d == '=')\r
-                                       t = Token.OP_SUB_ASSIGN;\r
-                               else\r
-                                       return Token.MINUS;\r
-                               doread = true;\r
-                               return t;\r
-                       }\r
-\r
-                       if (c == '='){\r
-                               /*if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_EQ;\r
-                               }*/\r
-                               return Token.ASSIGN;\r
-                       }\r
-\r
-                       if (c == '*'){\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_MULT_ASSIGN;\r
-                               }\r
-                               return Token.STAR;\r
-                       }\r
-\r
-                       if (c == '/'){\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_DIV_ASSIGN;\r
-                               }\r
-                               return Token.DIV;\r
-                       }\r
-\r
-                       if (c == '\\'){\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_IDIV_ASSIGN;\r
-                               }\r
-                               return Token.OP_IDIV;\r
-                       }\r
-\r
-                       if (c == '^'){\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_EXP_ASSIGN;\r
-                               }\r
-                               return Token.OP_EXP;\r
-                       }\r
-\r
-                       if (c == '<'){\r
-                               if (d == '>')\r
-                               {\r
-                                       doread = true;\r
-                                       return Token.OP_NE;\r
-                               }\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_LE;\r
-                               }\r
-                               return Token.OP_LT;\r
-                       }\r
-\r
-                       if (c == '>'){\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.OP_GE;\r
-                               }\r
-                               return Token.OP_GT;\r
-                       }\r
-                       if (c == ':'){\r
-                               if (d == '='){\r
-                                       doread = true;\r
-                                       return Token.ATTR_ASSIGN;\r
-                               }\r
-                               return Token.COLON;\r
-                       }                       \r
-                       return Token.ERROR;\r
-               }\r
-\r
-               bool decimal_digits (int c)\r
-               {\r
-                       int d;\r
-                       bool seen_digits = false;\r
-                       \r
-                       if (c != -1)\r
-                               number.Append ((char) c);\r
-                       \r
-                       while ((d = peekChar ()) != -1){\r
-                               if (Char.IsDigit ((char)d)){\r
-                                       number.Append ((char) d);\r
-                                       getChar ();\r
-                                       seen_digits = true;\r
-                               } else\r
-                                       break;\r
-                       }\r
-                       return seen_digits;\r
-               }\r
-\r
-               void hex_digits (int c)\r
-               {\r
-                       int d;\r
-\r
-                       if (c != -1)\r
-                               number.Append ((char) c);\r
-                       while ((d = peekChar ()) != -1){\r
-                               char e = Char.ToUpper ((char) d);\r
-                               \r
-                               if (Char.IsDigit (e) ||\r
-                                   (e >= 'A' && e <= 'F')){\r
-                                       number.Append ((char) e);\r
-                                       getChar ();\r
-                               } else\r
-                                       break;\r
-                       }\r
-               }\r
-               \r
-               int real_type_suffix (int c)\r
-               {\r
-                       int t;\r
-                       \r
-                       switch (c){\r
-                       case 'F': case 'f':\r
-                               t =  Token.LITERAL_SINGLE;\r
-                               break;\r
-                       case 'D': case 'd':\r
-                               t = Token.LITERAL_DOUBLE;\r
-                               break;\r
-                       case 'M': case 'm':\r
-                                t= Token.LITERAL_DECIMAL;\r
-                               break;\r
-                       default:\r
-                               return Token.NONE;\r
-                       }\r
-                       getChar ();\r
-                       return t;\r
-               }\r
-\r
-               int integer_type_suffix (int c)\r
-               {\r
-                       // FIXME: Handle U and L suffixes.\r
-                       // We also need to see in which kind of\r
-                       // Int the thing fits better according to the spec.\r
-                       return Token.LITERAL_INTEGER;\r
-               }\r
-               \r
-               void adjust_int (int t)\r
-               {\r
-                       val = new System.Int32();\r
-                       val = System.Int32.Parse (number.ToString (), 0);\r
-               }\r
-\r
-               int adjust_real (int t)\r
-               {\r
-                       string s = number.ToString ();\r
-\r
-                       Console.WriteLine (s);\r
-                       switch (t){\r
-                       case Token.LITERAL_DECIMAL:\r
-                               val = new System.Decimal ();\r
-                               val = System.Decimal.Parse (\r
-                                       s, styles, csharp_format_info);\r
-                               break;\r
-                       case Token.LITERAL_DOUBLE:\r
-                               val = new System.Double ();\r
-                               val = System.Double.Parse (\r
-                                       s, styles, csharp_format_info);\r
-                               break;\r
-                       case Token.LITERAL_SINGLE:\r
-                               val = new System.Double ();\r
-                               val = (float) System.Double.Parse (\r
-                                       s, styles, csharp_format_info);\r
-                               break;\r
-\r
-                       case Token.NONE:\r
-                               val = new System.Double ();\r
-                               val = System.Double.Parse (\r
-                                       s, styles, csharp_format_info);\r
-                               t = Token.LITERAL_DOUBLE;\r
-                               break;\r
-                       }\r
-                       return t;\r
-               }\r
-\r
-               //\r
-               // Invoked if we know we have .digits or digits\r
-               //\r
-               int is_number (int c)\r
-               {\r
-                       bool is_real = false;\r
-                       number = new System.Text.StringBuilder ();\r
-                       int type;\r
-\r
-                       number.Length = 0;\r
-\r
-                       if (Char.IsDigit ((char)c)){\r
-                               if (c == '0' && peekChar () == 'x' || peekChar () == 'X'){\r
-                                       getChar ();\r
-                                       hex_digits (-1);\r
-                                       val = new System.Int32 ();\r
-                                       val = System.Int32.Parse (number.ToString (), NumberStyles.HexNumber);\r
-                                       return integer_type_suffix (peekChar ());\r
-                               }\r
-                               decimal_digits (c);\r
-                               c = getChar ();\r
-                       }\r
-\r
-                       //\r
-                       // We need to handle the case of\r
-                       // "1.1" vs "1.string" (LITERAL_SINGLE vs NUMBER DOT IDENTIFIER)\r
-                       //\r
-                       if (c == '.'){\r
-                               if (decimal_digits ('.')){\r
-                                       is_real = true;\r
-                                       c = peekChar ();\r
-                               } else {\r
-                                       putback ('.');\r
-                                       number.Length -= 1;\r
-                                       adjust_int (Token.LITERAL_INTEGER);\r
-                                       return Token.LITERAL_INTEGER;\r
-                               }\r
-                       }\r
-                       \r
-                       if (c == 'e' || c == 'E'){\r
-                               is_real = true;\r
-                               number.Append ("e");\r
-                               getChar ();\r
-                               \r
-                               c = peekChar ();\r
-                               if (c == '+'){\r
-                                       number.Append ((char) c);\r
-                                       getChar ();\r
-                                       c = peekChar ();\r
-                               } else if (c == '-'){\r
-                                       number.Append ((char) c);\r
-                                       getChar ();\r
-                                       c = peekChar ();\r
-                               }\r
-                               decimal_digits (-1);\r
-                               c = peekChar ();\r
-                       }\r
-\r
-                       type = real_type_suffix (c);\r
-                       if (type == Token.NONE && !is_real){\r
-                               type = integer_type_suffix (c);\r
-                               adjust_int (type);\r
-                               putback (c);\r
-                               return type;\r
-                       } else\r
-                               is_real = true;\r
-\r
-                       if (is_real)\r
-                               return adjust_real (type);\r
-\r
-                       Console.WriteLine ("This should not be reached");\r
-                       throw new Exception ("Is Number should never reach this point");\r
-               }\r
-                       \r
-               int escape (int c)\r
-               {\r
-                       return peekChar ();\r
-               }\r
-\r
-               int getChar ()\r
-               {\r
-                       if (putback_char != -1){\r
-                               int x = putback_char;\r
-                               putback_char = -1;\r
-\r
-                               return x;\r
-                       }\r
-                       return reader.Read ();\r
-               }\r
-\r
-               int peekChar ()\r
-               {\r
-                       if (putback_char != -1)\r
-                               return putback_char;\r
-                       return reader.Peek ();\r
-               }\r
-\r
-               void putback (int c)\r
-               {\r
-                       if (putback_char != -1)\r
-                               throw new Exception ("This should not happen putback on putback");\r
-                       putback_char = c;\r
-               }\r
-\r
-               public bool advance ()\r
-               {\r
-                       return current_token != Token.EOF ;\r
-               }\r
-\r
-               public Object Value {\r
-                       get {\r
-                               return val;\r
-                       }\r
-               }\r
-\r
-               public Object value ()\r
-               {\r
-                       return val;\r
-               }\r
-\r
-               private bool IsEOL(int currentChar)\r
-               {\r
-                       if (currentChar ==  0x0D)\r
-                       {\r
-                               if (peekChar() ==  0x0A) // if it is a CR-LF pair consume LF also\r
-                                       getChar();\r
-\r
-                               return true;\r
-                       }\r
-                       return (currentChar ==  -1 || currentChar ==  0x0A || currentChar ==  0x2028 || currentChar ==  0x2029);\r
-               }\r
-\r
-               private int DropComments()              \r
-               {\r
-                       int d;\r
-                       while (!IsEOL(d = getChar ()))\r
-                               col++;\r
-                       line++;\r
-                       ref_line++;\r
-                       col = 0;\r
-\r
-                       return Token.EOL;\r
-               }       \r
-                       \r
-               public int token ()\r
-               {\r
-                       int lastToken = current_token;\r
-                       do\r
-                       {\r
-                               current_token = xtoken ();\r
-                               if (current_token == 0) \r
-                                       return Token.EOF;\r
-                               if (current_token == Token.REM)\r
-                                       current_token = DropComments();\r
-                       } while (lastToken == Token.EOL && current_token == Token.EOL);\r
-\r
-                       return current_token;\r
-               }\r
-\r
-               private string GetIdentifier()\r
-               {\r
-                       int c = getChar();\r
-                       if (is_identifier_start_character ((char) c))\r
-                               return GetIdentifier(c);\r
-                       else\r
-                               return null;\r
-               }\r
-\r
-               private string GetIdentifier(int c)\r
-               {\r
-                       System.Text.StringBuilder id = new System.Text.StringBuilder ();\r
-\r
-                       id.Append ((char) c);\r
-                               \r
-                       while ((c = peekChar ()) != -1) \r
-                       {\r
-                               if (is_identifier_part_character ((char) c))\r
-                               {\r
-                                       id.Append ((char)getChar ());\r
-                                       col++;\r
-                               } \r
-                               else \r
-                                       break;\r
-                       }\r
-\r
-                       return id.ToString ();\r
-               }\r
-\r
-               private bool tokens_seen = false;\r
-\r
-               public int xtoken ()\r
-               {\r
-                       int t;\r
-                       bool doread = false;\r
-                       int c;\r
-\r
-                       val = null;\r
-                       for (;(c = getChar ()) != -1; col++) {\r
-                       \r
-                               // Handle line comments.\r
-                               if (c == '\'')\r
-                                       return Token.REM;\r
-                                       \r
-                               // Handle line continuation character\r
-                               if (c == '_') \r
-                               {\r
-                                       int d = getChar();\r
-                                       putback(d);\r
-                                       if (!is_identifier_part_character((char)d)) {\r
-                                               while ((c = getChar ()) != -1 && !IsEOL(c)) {}\r
-                                               c = getChar ();                 \r
-                                       }               \r
-                               }\r
-                               // Handle EOL.\r
-                               if (IsEOL(c))\r
-                               {\r
-                                       line++;\r
-                                       ref_line++;\r
-                                       col = 0;\r
-                                       tokens_seen = false;\r
-                                       if (current_token == Token.EOL) // if last token was also EOL keep skipping\r
-                                               continue;\r
-                                       return Token.EOL;\r
-                               }\r
-                               \r
-                               // Handle escaped identifiers\r
-                               if (c == '[')\r
-                               {\r
-                                       if ((val = GetIdentifier()) == null)\r
-                                               break;\r
-                                       if ((c = getChar()) != ']')\r
-                                               break;\r
-                                       tokens_seen = true;\r
-                                       return Token.IDENTIFIER;\r
-                               }\r
-\r
-                               // Handle unescaped identifiers\r
-                               if (is_identifier_start_character ((char) c))\r
-                               {\r
-                                       string id;\r
-                                       if ((id = GetIdentifier(c)) == null)\r
-                                               break;\r
-                                       val = id;\r
-                                       tokens_seen = true;\r
-                                       if (is_keyword(id) && (current_token != Token.DOT))\r
-                                               return getKeyword(id);\r
-                                       return Token.IDENTIFIER;\r
-                               }\r
-\r
-                               // handle numeric literals\r
-                               if (c == '.')\r
-                               {\r
-                                       tokens_seen = true;\r
-                                       if (Char.IsDigit ((char) peekChar ()))\r
-                                               return is_number (c);\r
-                                       return Token.DOT;\r
-                               }\r
-                               \r
-                               if (Char.IsDigit ((char) c))\r
-                               {\r
-                                       tokens_seen = true;\r
-                                       return is_number (c);\r
-                               }\r
-\r
-                               if (c == '#' && !tokens_seen)\r
-                               {\r
-                                       bool cont = true;\r
-                                       \r
-                               start_again:\r
-                                       \r
-                                       cont = handle_preprocessing_directive (cont);\r
-\r
-                                       if (cont)\r
-                                       {\r
-                                               col = 0;\r
-                                               continue;\r
-                                       }\r
-                                       col = 1;\r
-\r
-                                       bool skipping = false;\r
-                                       for (;(c = getChar ()) != -1; col++)\r
-                                       {\r
-                                               if (IsEOL(c))\r
-                                               {\r
-                                                       col = 0;\r
-                                                       line++;\r
-                                                       ref_line++;\r
-                                                       skipping = false;\r
-                                               } \r
-                                               else if (c == ' ' || c == '\t' || c == '\v' || c == '\r' || c == 0xa0)\r
-                                                       continue;\r
-                                               else if (c != '#')\r
-                                               {\r
-                                                       skipping = true;\r
-                                                       continue;\r
-                                               }       \r
-                                               if (c == '#' && !skipping)\r
-                                                       goto start_again;\r
-                                       }\r
-                                       tokens_seen = false;\r
-                                       if (c == -1)\r
-                                               Report.Error (1027, Location, "#endif/#endregion expected");\r
-                                       continue;\r
-                               }\r
-                               \r
-                               if ((t = is_punct ((char)c, ref doread)) != Token.ERROR){\r
-                                       if (doread){\r
-                                               getChar ();\r
-                                               col++;\r
-                                       }\r
-                                       tokens_seen = true;\r
-                                       return t;\r
-                               }\r
-                               \r
-                               // Treat string literals\r
-                               if (c == '"'){\r
-                                       System.Text.StringBuilder s = new System.Text.StringBuilder ();\r
-\r
-                                       tokens_seen = true;\r
-\r
-                                       while ((c = getChar ()) != -1){\r
-                                               if (c == '"'){\r
-                                                       if (peekChar() == '"')\r
-                                                               getChar();\r
-                                                       else {\r
-                                                               val = s.ToString ();\r
-                                                               return Token.LITERAL_STRING;\r
-                                                       }\r
-                                               }\r
-\r
-                                               if (IsEOL(c))\r
-                                                       return Token.ERROR;\r
-                                                       \r
-                                               s.Append ((char) c);\r
-                                       }\r
-                               }\r
-                       \r
-                               // expand tabs for location and ignore it as whitespace\r
-                               if (c == '\t')\r
-                               {\r
-                                       col = (((col + ExpandedTabsSize) / ExpandedTabsSize) * ExpandedTabsSize) - 1;\r
-                                       continue;\r
-                               }\r
-\r
-                               // white space\r
-                               if (c == ' ' || c == '\f' || c == '\v')\r
-                                       continue;\r
-\r
-                               error_details = ((char)c).ToString ();\r
-                               \r
-                               return Token.ERROR;\r
-                       }\r
-\r
-                       if (current_token != Token.EOL) // if last token wasn't EOL send it before EOF\r
-                               return Token.EOL;\r
-                       \r
-                       return Token.EOF;\r
-               }\r
-\r
-               public void cleanup ()\r
-               {\r
-/* borrowed from mcs - have to work it to have preprocessing in mbas\r
-\r
-                       if (ifstack != null && ifstack.Count >= 1) {\r
-                               int state = (int) ifstack.Pop ();\r
-                               if ((state & REGION) != 0)\r
-                                       Report.Error (1038, "#endregion directive expected");\r
-                               else \r
-                                       Report.Error (1027, "#endif directive expected");\r
-                       }\r
-*/                             \r
-               }\r
-\r
-               public Tokenizer (System.IO.TextReader input, string fname, ArrayList defines)\r
-               {\r
-                       this.ref_name = fname;\r
-                       reader = input;\r
-                       putback_char = -1;\r
-                       \r
-                       Location.Push (fname);\r
-               }\r
-\r
-               static StringBuilder static_cmd_arg = new System.Text.StringBuilder ();\r
-               \r
-               void get_cmd_arg (out string cmd, out string arg)\r
-               {\r
-                       int c;\r
-                       \r
-                       tokens_seen = false;\r
-                       arg = "";\r
-                       static_cmd_arg.Length = 0;\r
-                               \r
-                       while ((c = getChar ()) != -1 && (c != '\n') && (c != ' ') && (c != '\t') && (c != '\r')){\r
-                               static_cmd_arg.Append ((char) c);\r
-                       }\r
-\r
-                       cmd = static_cmd_arg.ToString().ToLower();\r
-\r
-                       if (c == '\n'){\r
-                               line++;\r
-                               ref_line++;\r
-                               return;\r
-                       } else if (c == '\r')\r
-                               col = 0;\r
-\r
-                       // skip over white space\r
-                       while ((c = getChar ()) != -1 && (c != '\n') && ((c == '\r') || (c == ' ') || (c == '\t')))\r
-                               ;\r
-\r
-                       if (c == '\n'){\r
-                               line++;\r
-                               ref_line++;\r
-                               return;\r
-                       } else if (c == '\r'){\r
-                               col = 0;\r
-                               return;\r
-                       }\r
-                       \r
-                       static_cmd_arg.Length = 0;\r
-                       static_cmd_arg.Append ((char) c);\r
-                       \r
-                       while ((c = getChar ()) != -1 && (c != '\n') && (c != '\r')){\r
-                               static_cmd_arg.Append ((char) c);\r
-                       }\r
-\r
-                       if (c == '\n'){\r
-                               line++;\r
-                               ref_line++;\r
-                       } else if (c == '\r')\r
-                               col = 0;\r
-                       arg = static_cmd_arg.ToString ().Trim ();\r
-                       \r
-                       if (cmd == "end" && arg.ToLower() == "region") {\r
-                               cmd = "end region";\r
-                               arg = "";       \r
-                       }\r
-                       if (cmd == "end" && arg.ToLower() == "if") {\r
-                               cmd = "end if";\r
-                               arg = "";       \r
-                       }                       \r
-                               \r
-               }\r
-\r
-               //\r
-               // Handles the #line directive\r
-               //\r
-               bool PreProcessLine (string arg)\r
-               {\r
-                       if (arg == "")\r
-                               return false;\r
-\r
-                       if (arg == "default"){\r
-                               ref_line = line;\r
-                               ref_name = file_name;\r
-                               Location.Push (ref_name);\r
-                               return true;\r
-                       }\r
-                       \r
-                       try {\r
-                               int pos;\r
-\r
-                               if ((pos = arg.IndexOf (' ')) != -1 && pos != 0){\r
-                                       ref_line = System.Int32.Parse (arg.Substring (0, pos));\r
-                                       pos++;\r
-                                       \r
-                                       char [] quotes = { '\"' };\r
-                                       \r
-                                       string name = arg.Substring (pos). Trim (quotes);\r
-                                       ref_name = name; // TODO: Synchronize with mcs: Location.LookupFile (name);\r
-                                       Location.Push (ref_name);\r
-                               } else {\r
-                                       ref_line = System.Int32.Parse (arg);\r
-                               }\r
-                       } catch {\r
-                               return false;\r
-                       }\r
-                       \r
-                       return true;\r
-               }\r
-\r
-               //\r
-               // Handles #define and #undef\r
-               //\r
-               void PreProcessDefinition (bool is_define, string arg)\r
-               {\r
-                       if (arg == "" || arg == "true" || arg == "false"){\r
-                               Report.Error (1001, Location, "Missing identifer to pre-processor directive");\r
-                               return;\r
-                       }\r
-\r
-                       char[] whitespace = { ' ', '\t' };\r
-                       if (arg.IndexOfAny (whitespace) != -1){\r
-                               Report.Error (1025, Location, "Single-line comment or end-of-line expected");\r
-                               return;\r
-                       }\r
-\r
-                       foreach (char c in arg){\r
-                               if (!Char.IsLetter (c) && (c != '_')){\r
-                                       Report.Error (1001, Location, "Identifier expected");\r
-                                       return;\r
-                               }\r
-                       }\r
-\r
-                       if (is_define){\r
-                               if (defines == null)\r
-                                       defines = new Hashtable ();\r
-                               define (arg);\r
-                       } else {\r
-                               if (defines == null)\r
-                                       return;\r
-                               if (defines.Contains (arg))\r
-                                       defines.Remove (arg);\r
-                       }\r
-               }\r
-\r
-               bool eval_val (string s)\r
-               {\r
-                       if (s == "true")\r
-                               return true;\r
-                       if (s == "false")\r
-                               return false;\r
-                       \r
-                       if (defines == null)\r
-                               return false;\r
-                       if (defines.Contains (s))\r
-                               return true;\r
-\r
-                       return false;\r
-               }\r
-\r
-               bool pp_primary (ref string s)\r
-               {\r
-                       s = s.Trim ();\r
-                       int len = s.Length;\r
-\r
-                       if (len > 0){\r
-                               char c = s [0];\r
-                               \r
-                               if (c == '('){\r
-                                       s = s.Substring (1);\r
-                                       bool val = pp_expr (ref s);\r
-                                       if (s.Length > 0 && s [0] == ')'){\r
-                                               s = s.Substring (1);\r
-                                               return val;\r
-                                       }\r
-                                       Error_InvalidDirective ();\r
-                                       return false;\r
-                               }\r
-                               \r
-                               if (is_identifier_start_character (c)){\r
-                                       int j = 1;\r
-\r
-                                       while (j < len){\r
-                                               c = s [j];\r
-                                               \r
-                                               if (is_identifier_part_character (c)){\r
-                                                       j++;\r
-                                                       continue;\r
-                                               }\r
-                                               bool v = eval_val (s.Substring (0, j));\r
-                                               s = s.Substring (j);\r
-                                               return v;\r
-                                       }\r
-                                       bool vv = eval_val (s);\r
-                                       s = "";\r
-                                       return vv;\r
-                               }\r
-                       }\r
-                       Error_InvalidDirective ();\r
-                       return false;\r
-               }\r
-               \r
-               bool pp_unary (ref string s)\r
-               {\r
-                       s = s.Trim ();\r
-                       int len = s.Length;\r
-\r
-                       if (len > 0){\r
-                               if (s [0] == '!'){\r
-                                       if (len > 1 && s [1] == '='){\r
-                                               Error_InvalidDirective ();\r
-                                               return false;\r
-                                       }\r
-                                       s = s.Substring (1);\r
-                                       return ! pp_primary (ref s);\r
-                               } else\r
-                                       return pp_primary (ref s);\r
-                       } else {\r
-                               Error_InvalidDirective ();\r
-                               return false;\r
-                       }\r
-               }\r
-               \r
-               bool pp_eq (ref string s)\r
-               {\r
-                       bool va = pp_unary (ref s);\r
-\r
-                       s = s.Trim ();\r
-                       int len = s.Length;\r
-                       if (len > 0){\r
-                               if (s [0] == '='){\r
-                                       if (len > 2 && s [1] == '='){\r
-                                               s = s.Substring (2);\r
-                                               return va == pp_unary (ref s);\r
-                                       } else {\r
-                                               Error_InvalidDirective ();\r
-                                               return false;\r
-                                       }\r
-                               } else if (s [0] == '!' && len > 1 && s [1] == '='){\r
-                                       s = s.Substring (2);\r
-\r
-                                       return va != pp_unary (ref s);\r
-\r
-                               } \r
-                       }\r
-\r
-                       return va;\r
-                               \r
-               }\r
-               \r
-               bool pp_and (ref string s)\r
-               {\r
-                       bool va = pp_eq (ref s);\r
-\r
-                       s = s.Trim ();\r
-                       int len = s.Length;\r
-                       if (len > 0){\r
-                               if (s [0] == '&'){\r
-                                       if (len > 2 && s [1] == '&'){\r
-                                               s = s.Substring (2);\r
-                                               return (va & pp_eq (ref s));\r
-                                       } else {\r
-                                               Error_InvalidDirective ();\r
-                                               return false;\r
-                                       }\r
-                               } \r
-                       }\r
-                       return va;\r
-               }\r
-               \r
-               //\r
-               // Evaluates an expression for `#if' or `#elif'\r
-               //\r
-               bool pp_expr (ref string s)\r
-               {\r
-                       bool va = pp_and (ref s);\r
-                       s = s.Trim ();\r
-                       int len = s.Length;\r
-                       if (len > 0){\r
-                               char c = s [0];\r
-                               \r
-                               if (c == '|'){\r
-                                       if (len > 2 && s [1] == '|'){\r
-                                               s = s.Substring (2);\r
-                                               return va | pp_expr (ref s);\r
-                                       } else {\r
-                                               Error_InvalidDirective ();\r
-                                               return false;\r
-                                       }\r
-                               } \r
-                       }\r
-                       \r
-                       return va;\r
-               }\r
-\r
-               bool eval (string s)\r
-               {\r
-                       bool v = pp_expr (ref s);\r
-                       s = s.Trim ();\r
-                       if (s.Length != 0){\r
-                               Error_InvalidDirective ();\r
-                               return false;\r
-                       }\r
-\r
-                       return v;\r
-               }\r
-               \r
-               void Error_InvalidDirective ()\r
-               {\r
-                       Report.Error (1517, Location, "Invalid pre-processor directive");\r
-               }\r
-\r
-               void Error_UnexpectedDirective (string extra)\r
-               {\r
-                       Report.Error (\r
-                               1028, Location,\r
-                               "Unexpected processor directive (" + extra + ")");\r
-               }\r
-\r
-               void Error_TokensSeen ()\r
-               {\r
-                       Report.Error (\r
-                               1032, Location,\r
-                               "Cannot define or undefine pre-processor symbols after a token in the file");\r
-               }\r
-               \r
-               //\r
-               // if true, then the code continues processing the code\r
-               // if false, the code stays in a loop until another directive is\r
-               // reached.\r
-               //\r
-               bool handle_preprocessing_directive (bool caller_is_taking)\r
-               {\r
-                       char [] blank = { ' ', '\t' };\r
-                       string cmd, arg;\r
-                       bool region_directive = false;\r
-\r
-                       get_cmd_arg (out cmd, out arg);\r
-                       // Eat any trailing whitespaces and single-line comments\r
-                       if (arg.IndexOf ("//") != -1)\r
-                               arg = arg.Substring (0, arg.IndexOf ("//"));\r
-                       arg = arg.TrimEnd (' ', '\t');\r
-\r
-                       //\r
-                       // The first group of pre-processing instructions is always processed\r
-                       //\r
-                       switch (cmd.ToLower()){\r
-                       case "line":\r
-                               if (!PreProcessLine (arg))\r
-                                       Report.Error (\r
-                                               1576, Location,\r
-                                               "Argument to #line directive is missing or invalid");\r
-                               return true;\r
-\r
-                       case "region":\r
-                               region_directive = true;\r
-                               arg = "true";\r
-                               goto case "if";\r
-\r
-                       case "end region":\r
-                               region_directive = true;\r
-                               goto case "end if";\r
-                               \r
-                       case "if":\r
-                               if (arg == ""){\r
-                                       Error_InvalidDirective ();\r
-                                       return true;\r
-                               }\r
-                               bool taking = false;\r
-                               if (ifstack == null)\r
-                                       ifstack = new Stack ();\r
-\r
-                               if (ifstack.Count == 0){\r
-                                       taking = true;\r
-                               } else {\r
-                                       int state = (int) ifstack.Peek ();\r
-                                       if ((state & TAKING) != 0)\r
-                                               taking = true;\r
-                               }\r
-\r
-                               if (eval (arg) && taking){\r
-                                       int push = TAKING | TAKEN_BEFORE | PARENT_TAKING;\r
-                                       if (region_directive)\r
-                                               push |= REGION;\r
-                                       ifstack.Push (push);\r
-                                       return true;\r
-                               } else {\r
-                                       int push = (taking ? PARENT_TAKING : 0);\r
-                                       if (region_directive)\r
-                                               push |= REGION;\r
-                                       ifstack.Push (push);\r
-                                       return false;\r
-                               }\r
-                               \r
-                       case "end if":\r
-                               if (ifstack == null || ifstack.Count == 0){\r
-                                       Error_UnexpectedDirective ("no #if for this #endif");\r
-                                       return true;\r
-                               } else {\r
-                                       int pop = (int) ifstack.Pop ();\r
-                                       \r
-                                       if (region_directive && ((pop & REGION) == 0))\r
-                                               Report.Error (1027, Location, "#endif directive expected");\r
-                                       else if (!region_directive && ((pop & REGION) != 0))\r
-                                               Report.Error (1038, Location, "#endregion directive expected");\r
-                                       \r
-                                       if (ifstack.Count == 0)\r
-                                               return true;\r
-                                       else {\r
-                                               int state = (int) ifstack.Peek ();\r
-\r
-                                               if ((state & TAKING) != 0)\r
-                                                       return true;\r
-                                               else\r
-                                                       return false;\r
-                                       }\r
-                               }\r
-\r
-                       case "elseif":\r
-                               if (ifstack == null || ifstack.Count == 0){\r
-                                       Error_UnexpectedDirective ("no #if for this #elif");\r
-                                       return true;\r
-                               } else {\r
-                                       int state = (int) ifstack.Peek ();\r
-\r
-                                       if ((state & REGION) != 0) {\r
-                                               Report.Error (1038, Location, "#endregion directive expected");\r
-                                               return true;\r
-                                       }\r
-\r
-                                       if ((state & ELSE_SEEN) != 0){\r
-                                               Error_UnexpectedDirective ("#elif not valid after #else");\r
-                                               return true;\r
-                                       }\r
-\r
-                                       if ((state & (TAKEN_BEFORE | TAKING)) != 0)\r
-                                               return false;\r
-\r
-                                       if (eval (arg) && ((state & PARENT_TAKING) != 0)){\r
-                                               state = (int) ifstack.Pop ();\r
-                                               ifstack.Push (state | TAKING | TAKEN_BEFORE);\r
-                                               return true;\r
-                                       } else \r
-                                               return false;\r
-                               }\r
-\r
-                       case "else":\r
-                               if (ifstack == null || ifstack.Count == 0){\r
-                                       Report.Error (\r
-                                               1028, Location,\r
-                                               "Unexpected processor directive (no #if for this #else)");\r
-                                       return true;\r
-                               } else {\r
-                                       int state = (int) ifstack.Peek ();\r
-\r
-                                       if ((state & REGION) != 0) {\r
-                                               Report.Error (1038, Location, "#endregion directive expected");\r
-                                               return true;\r
-                                       }\r
-\r
-                                       if ((state & ELSE_SEEN) != 0){\r
-                                               Error_UnexpectedDirective ("#else within #else");\r
-                                               return true;\r
-                                       }\r
-\r
-                                       ifstack.Pop ();\r
-\r
-                                       bool ret;\r
-                                       if ((state & TAKEN_BEFORE) == 0){\r
-                                               ret = ((state & PARENT_TAKING) != 0);\r
-                                       } else\r
-                                               ret = false;\r
-                                       \r
-                                       if (ret)\r
-                                               state |= TAKING;\r
-                                       else\r
-                                               state &= ~TAKING;\r
-                                       \r
-                                       ifstack.Push (state | ELSE_SEEN);\r
-                                       \r
-                                       return ret;\r
-                               }\r
-                       }\r
-\r
-                       //\r
-                       // These are only processed if we are in a `taking' block\r
-                       //\r
-                       if (!caller_is_taking)\r
-                               return false;\r
-                                       \r
-                       switch (cmd.ToLower()){\r
-                       case "define":\r
-                               /* if (any_token_seen){\r
-                                       Error_TokensSeen ();\r
-                                       return true;\r
-                               } */\r
-                               PreProcessDefinition (true, arg);\r
-                               return true;\r
-\r
-                       case "undef":\r
-                               /* if (any_token_seen){\r
-                                       Error_TokensSeen ();\r
-                                       return true;\r
-                               } */\r
-                               PreProcessDefinition (false, arg);\r
-                               return true;\r
-\r
-                       case "error":\r
-                               Report.Error (1029, Location, "#error: '" + arg + "'");\r
-                               return true;\r
-\r
-                       case "warning":\r
-                               Report.Warning (1030, Location, "#warning: '" + arg + "'");\r
-                               return true;\r
-                       }\r
-\r
-                       Report.Error (1024, Location, "Preprocessor directive expected (got: " + cmd + ")");\r
-                       return true;\r
-\r
-               }\r
-\r
-       }\r
-}\r
+//
+// Mono.MonoBASIC.Tokenizer.cs: The Tokenizer for the MonoBASIC compiler
+//
+// Author: A Rafael D Teixeira (rafaelteixeirabr@hotmail.com)
+//        
+// Based on cs-tokenizer.cs by Miguel de Icaza (miguel@gnu.org)
+//
+// Licensed under the terms of the GNU GPL
+//
+// Copyright (C) 2001 A Rafael D Teixeira
+//
+
+namespace Mono.MonoBASIC
+{
+       using System;
+       using System.Text;
+       using System.Collections;
+       using System.IO;
+       using System.Globalization;
+       using Mono.Languages;
+       using Mono.MonoBASIC;
+       
+       /// <summary>
+       ///    Tokenizer for MonoBASIC source code. 
+       /// </summary>
+       
+       public class Tokenizer : yyParser.yyInput
+       {
+               TextReader reader;
+               string file_name;
+               string ref_name;
+               int ref_line = 0;
+               int line = 0;
+               int col = 1;
+               public int current_token = Token.ERROR;
+               bool handle_get_set = false;
+               bool cant_have_a_type_character = false;
+
+               public int ExpandedTabsSize = 4; 
+
+               public string location {
+                       get {
+                               string det;
+
+                               if (current_token == Token.ERROR)
+                                       det = "detail: " + error_details;
+                               else
+                                       det = "";
+                               
+                               return "Line:     "+line+" Col: "+col + "\n" +
+                                      "VirtLine: "+ref_line +
+                                      " Token: "+current_token + " " + det;
+                       }
+               }
+
+               public bool properties {
+                       get {
+                               return handle_get_set;
+                       }
+
+                       set {
+                               handle_get_set = value;
+                       }
+                }
+               
+               //
+               // Class variables
+               // 
+               static Hashtable keywords;
+               static NumberStyles styles;
+               static NumberFormatInfo csharp_format_info;
+               
+               //
+               // Values for the associated token returned
+               //
+               StringBuilder number;
+               int putback_char = -1;
+               Object val;
+               
+               //
+               // Details about the error encoutered by the tokenizer
+               //
+               string error_details;
+               
+               public string error {
+                       get {
+                               return error_details;
+                       }
+               }
+
+               
+               public string Source {
+                       get {
+                               return file_name;
+                       }
+
+                       set {
+                               file_name = value;
+                               ref_name = value;
+                               Location.SetCurrentSource(file_name);
+                       }
+               }
+
+               public string EffectiveSource {
+                       get {
+                               return ref_name;
+                       }
+                       set {
+                               ref_name = value;
+                               Location.SetCurrentSource(ref_name);
+                       }
+               }
+
+               public int Line {
+                       get {
+                               return line;
+                       }
+               }
+
+               public int EffectiveLine {
+                       get {
+                               return ref_line;
+                       }
+                       set {
+                               ref_line = value;
+                       }
+               }
+
+               public int Col {
+                       get {
+                               return col;
+                       }
+               }
+               
+               static void initTokens ()
+               {
+                       keywords = new Hashtable ();
+
+                       keywords.Add ("addhandler", Token.ADDHANDLER);
+                       keywords.Add ("addressof", Token.ADDRESSOF);
+                       keywords.Add ("alias", Token.ALIAS);
+                       keywords.Add ("and", Token.AND);
+                       keywords.Add ("andalso", Token.ANDALSO);
+                       keywords.Add ("ansi", Token.ANSI);
+                       keywords.Add ("as", Token.AS);
+                       keywords.Add ("assembly", Token.ASSEMBLY);
+                       keywords.Add ("auto", Token.AUTO);
+                       keywords.Add ("binary", Token.BINARY);
+                       keywords.Add ("boolean", Token.BOOLEAN);
+                       keywords.Add ("byref", Token.BYREF);
+                       keywords.Add ("byte", Token.BYTE);
+                       keywords.Add ("byval", Token.BYVAL);
+                       keywords.Add ("call", Token.CALL);
+                       keywords.Add ("case", Token.CASE);
+                       keywords.Add ("catch", Token.CATCH);
+                       keywords.Add ("cbool", Token.CBOOL);
+                       keywords.Add ("cbyte", Token.CBYTE);
+                       keywords.Add ("cchar", Token.CCHAR);
+                       keywords.Add ("cdate", Token.CDATE);
+                       keywords.Add ("cdec", Token.CDEC);
+                       keywords.Add ("cdbl", Token.CDBL);
+                       keywords.Add ("char", Token.CHAR);
+                       keywords.Add ("cint", Token.CINT);
+                       keywords.Add ("class", Token.CLASS);
+                       keywords.Add ("clng", Token.CLNG);
+                       keywords.Add ("cobj", Token.COBJ);
+                       keywords.Add ("compare", Token.COMPARE);
+                       keywords.Add ("const", Token.CONST);
+                       keywords.Add ("cshort", Token.CSHORT);
+                       keywords.Add ("csng", Token.CSNG);
+                       keywords.Add ("cstr", Token.CSTR);
+                       keywords.Add ("ctype", Token.CTYPE);
+                       keywords.Add ("date", Token.DATE);
+                       keywords.Add ("decimal", Token.DECIMAL);
+                       keywords.Add ("declare", Token.DECLARE);
+                       keywords.Add ("default", Token.DEFAULT);
+                       keywords.Add ("delegate", Token.DELEGATE);
+                       keywords.Add ("dim", Token.DIM);
+                       keywords.Add ("do", Token.DO);
+                       keywords.Add ("double", Token.DOUBLE);
+                       keywords.Add ("each", Token.EACH);
+                       keywords.Add ("else", Token.ELSE);
+                       keywords.Add ("elseif", Token.ELSEIF);
+                       keywords.Add ("end", Token.END);
+                       keywords.Add ("enum", Token.ENUM);
+                       keywords.Add ("erase", Token.ERASE);
+                       keywords.Add ("error", Token.ERROR);
+                       keywords.Add ("event", Token.EVENT);
+                       keywords.Add ("exit", Token.EXIT);
+                       keywords.Add ("explicit", Token.EXPLICIT);
+                       keywords.Add ("false", Token.FALSE);
+                       keywords.Add ("finally", Token.FINALLY);
+                       keywords.Add ("for", Token.FOR);
+                       keywords.Add ("friend", Token.FRIEND);
+                       keywords.Add ("function", Token.FUNCTION);
+                       keywords.Add ("get", Token.GET);
+                       //keywords.Add ("gettype", Token.GETTYPE);
+                       keywords.Add ("goto", Token.GOTO);
+                       keywords.Add ("handles", Token.HANDLES);
+                       keywords.Add ("if", Token.IF);
+                       keywords.Add ("implements", Token.IMPLEMENTS);
+                       keywords.Add ("imports", Token.IMPORTS);
+                       keywords.Add ("in", Token.IN);
+                       keywords.Add ("inherits", Token.INHERITS);
+                       keywords.Add ("integer", Token.INTEGER);
+                       keywords.Add ("interface", Token.INTERFACE);
+                       keywords.Add ("is", Token.IS);
+                       keywords.Add ("let ", Token.LET );
+                       keywords.Add ("lib ", Token.LIB );
+                       keywords.Add ("like ", Token.LIKE );
+                       keywords.Add ("long", Token.LONG);
+                       keywords.Add ("loop", Token.LOOP);
+                       keywords.Add ("me", Token.ME);
+                       keywords.Add ("mod", Token.MOD);
+                       keywords.Add ("module", Token.MODULE);
+                       keywords.Add ("mustinherit", Token.MUSTINHERIT);
+                       keywords.Add ("mustoverride", Token.MUSTOVERRIDE);
+                       keywords.Add ("mybase", Token.MYBASE);
+                       keywords.Add ("myclass", Token.MYCLASS);
+                       keywords.Add ("namespace", Token.NAMESPACE);
+                       keywords.Add ("new", Token.NEW);
+                       keywords.Add ("next", Token.NEXT);
+                       keywords.Add ("not", Token.NOT);
+                       keywords.Add ("nothing", Token.NOTHING);
+                       keywords.Add ("notinheritable", Token.NOTINHERITABLE);
+                       keywords.Add ("notoverridable", Token.NOTOVERRIDABLE);
+                       keywords.Add ("object", Token.OBJECT);
+                       keywords.Add ("off", Token.OFF);
+                       keywords.Add ("on", Token.ON);
+                       keywords.Add ("option", Token.OPTION);
+                       keywords.Add ("optional", Token.OPTIONAL);
+                       keywords.Add ("or", Token.OR);
+                       keywords.Add ("orelse", Token.ORELSE);
+                       keywords.Add ("overloads", Token.OVERLOADS);
+                       keywords.Add ("overridable", Token.OVERRIDABLE);
+                       keywords.Add ("overrides", Token.OVERRIDES);
+                       keywords.Add ("paramarray", Token.PARAM_ARRAY);
+                       keywords.Add ("preserve", Token.PRESERVE);
+                       keywords.Add ("private", Token.PRIVATE);
+                       keywords.Add ("property", Token.PROPERTY);
+                       keywords.Add ("protected", Token.PROTECTED);
+                       keywords.Add ("public", Token.PUBLIC);
+                       keywords.Add ("raiseevent", Token.RAISEEVENT);
+                       keywords.Add ("readonly", Token.READONLY);
+                       keywords.Add ("redim", Token.REDIM);
+                       keywords.Add ("rem", Token.REM);
+                       keywords.Add ("removehandler", Token.REMOVEHANDLER);
+                       keywords.Add ("resume", Token.RESUME);
+                       keywords.Add ("return", Token.RETURN);
+                       keywords.Add ("select", Token.SELECT);
+                       keywords.Add ("set", Token.SET);
+                       keywords.Add ("shadows", Token.SHADOWS);
+                       keywords.Add ("shared", Token.SHARED);
+                       keywords.Add ("short", Token.SHORT);
+                       keywords.Add ("single", Token.SINGLE);
+                       keywords.Add ("sizeof", Token.SIZEOF);
+                       keywords.Add ("static", Token.STATIC);
+                       keywords.Add ("step", Token.STEP);
+                       keywords.Add ("stop", Token.STOP);
+                       keywords.Add ("strict", Token.STRICT);
+                       keywords.Add ("string", Token.STRING);
+                       keywords.Add ("structure", Token.STRUCTURE);
+                       keywords.Add ("sub", Token.SUB);
+                       keywords.Add ("synclock", Token.SYNCLOCK);
+                       keywords.Add ("text", Token.TEXT);
+                       keywords.Add ("then", Token.THEN);
+                       keywords.Add ("throw", Token.THROW);
+                       keywords.Add ("to", Token.TO);
+                       keywords.Add ("true", Token.TRUE);
+                       keywords.Add ("try", Token.TRY);
+                       keywords.Add ("typeof", Token.TYPEOF);
+                       keywords.Add ("unicode", Token.UNICODE);
+                       keywords.Add ("until", Token.UNTIL);
+                       keywords.Add ("variant", Token.VARIANT);
+                       keywords.Add ("when", Token.WHEN);
+                       keywords.Add ("while", Token.WHILE);
+                       keywords.Add ("with", Token.WITH);
+                       keywords.Add ("withevents", Token.WITHEVENTS);
+                       keywords.Add ("writeonly", Token.WRITEONLY);
+                       keywords.Add ("xor", Token.XOR);
+
+                       if (Parser.UseExtendedSyntax){
+                               keywords.Add ("yield", Token.YIELD);
+                       }
+
+               }
+
+               static Tokenizer ()
+               {
+                       initTokens ();
+                       csharp_format_info = new NumberFormatInfo ();
+                       csharp_format_info.CurrencyDecimalSeparator = ".";
+                       styles = NumberStyles.AllowExponent | NumberStyles.AllowDecimalPoint;
+               }
+
+               public Tokenizer (System.IO.TextReader input, string fname, ArrayList defines)
+               {
+                       this.Source = fname;
+
+                       reader = input;
+
+                       // putback an EOL at the beginning of a stream. This is a convenience that 
+                       // allows pre-processor directives to be added to the beginning of a vb file.
+                       putback('\n');
+               }
+
+               bool is_keyword (string name)
+               {
+                       bool res;
+                       name = name.ToLower();
+
+                       res = keywords.Contains(name);
+                       if ((name == "GET" || name == "SET") && handle_get_set == false)
+                               return false;
+                       return res;
+               }
+
+               int getKeyword (string name)
+               {
+                       return (int) (keywords [name.ToLower()]);
+               }
+               
+               public Location Location {
+                       get {
+                               return new Location (ref_line, col);
+                       }
+               }
+               
+               public bool PropertyParsing {
+                       get {
+                               return handle_get_set;
+                       }
+
+                       set {
+                               handle_get_set = value;
+                       }
+                }
+                               
+               bool is_identifier_start_character (char c)
+               {
+                       return Char.IsLetter (c) || c == '_' ;
+               }
+
+               bool is_identifier_part_character (char c)
+               {
+                       return (Char.IsLetter (c) || Char.IsDigit (c) || c == '_');
+               }
+
+               int is_punct (char c, ref bool doread)
+               {
+                       int d;
+                       int t;
+
+                       doread = false;
+                       
+                       error_details = c.ToString();
+                       
+                       d = peekChar ();
+                       
+                       switch (c){
+                       case '[':
+                               return Token.OPEN_BRACKET;
+                       case ']':
+                               return Token.CLOSE_BRACKET;
+                       case '{':
+                               return Token.OPEN_BRACE;
+                       case '}':
+                               return Token.CLOSE_BRACE;                               
+                       case '(':
+                               return Token.OPEN_PARENS;
+                       case ')':
+                               return Token.CLOSE_PARENS;
+                       case ',':
+                               return Token.COMMA;
+                       case '?':
+                               return Token.INTERR;
+                       case '!':
+                               if (is_identifier_start_character((char)d) || cant_have_a_type_character)
+                                       return Token.EXCLAMATION;
+                               return Token.SINGLETYPECHAR;
+                       case '$':
+                               if (cant_have_a_type_character)
+                                       return Token.ERROR;
+                               return Token.DOLAR_SIGN;
+                       case '@':
+                               if (cant_have_a_type_character)
+                                       return Token.ERROR;
+                               return Token.AT_SIGN;
+                       case '%':
+                               if (cant_have_a_type_character)
+                                       return Token.ERROR;
+                               return Token.PERCENT;
+                       case '#':
+                               if(tokens_seen)
+                               {
+                                       if (cant_have_a_type_character) 
+                                               return ExtractDateTimeLiteral();
+                                       else
+                                               return Token.NUMBER_SIGN;
+                               }
+                               else 
+                               {
+                                       tokens_seen = true;
+                                       return Token.HASH;
+                               } 
+                       case '&':
+                               if (!cant_have_a_type_character)
+                                       return Token.LONGTYPECHAR;
+                               t = handle_integer_literal_in_other_bases(d);
+                               if (t == Token.NONE) {
+                                       if (d == '=') {
+                                               doread = true;
+                                               t = Token.OP_CONCAT_ASSIGN;
+                                       } else 
+                                               t = Token.OP_CONCAT;
+                               }
+                               return t;                       
+                       }
+
+                       if (c == '+'){
+                               if (d == '+')
+                                       t = Token.OP_INC;
+                               else if (d == '=')
+                                       t = Token.OP_ADD_ASSIGN;
+                               else
+                                       return Token.PLUS;
+                               doread = true;
+                               return t;
+                       }
+                       if (c == '-'){
+                               if (d == '=')
+                                       t = Token.OP_SUB_ASSIGN;
+                               else
+                                       return Token.MINUS;
+                               doread = true;
+                               return t;
+                       }
+
+                       if (c == '='){
+                               return Token.ASSIGN;
+                       }
+
+                       if (c == '*'){
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.OP_MULT_ASSIGN;
+                               }
+                               return Token.STAR;
+                       }
+
+                       if (c == '/'){
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.OP_DIV_ASSIGN;
+                               }
+                               return Token.DIV;
+                       }
+
+                       if (c == '\\'){
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.OP_IDIV_ASSIGN;
+                               }
+                               return Token.OP_IDIV;
+                       }
+
+                       if (c == '^'){
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.OP_EXP_ASSIGN;
+                               }
+                               return Token.OP_EXP;
+                       }
+
+                       if (c == '<'){
+                               if (d == '>')
+                               {
+                                       doread = true;
+                                       return Token.OP_NE;
+                               }
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.OP_LE;
+                               }
+                               if (d == '<')
+                               {
+                                       doread = true;
+                                       return Token.OP_SHIFT_LEFT;
+                               }
+                               return Token.OP_LT;
+                       }
+
+                       if (c == '>'){
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.OP_GE;
+                               }
+                               if (d == '>')
+                               {
+                                       doread = true;
+                                       return Token.OP_SHIFT_RIGHT;
+                               }
+                               return Token.OP_GT;
+                       }
+                       
+                       if (c == ':'){
+                               if (d == '='){
+                                       doread = true;
+                                       return Token.ATTR_ASSIGN;
+                               }
+                               return Token.COLON;
+                       }                       
+                       
+                       return Token.ERROR;
+               }
+
+               bool decimal_digits (int c)
+               {
+                       int d;
+                       bool seen_digits = false;
+                       
+                       if (c != -1)
+                               number.Append ((char) c);
+                       
+                       while ((d = peekChar ()) != -1){
+                               if (Char.IsDigit ((char)d)){
+                                       number.Append ((char) d);
+                                       getChar ();
+                                       seen_digits = true;
+                               } else
+                                       break;
+                       }
+                       return seen_digits;
+               }
+
+               
+               int real_type_suffix (int c)
+               {
+                       int t;
+                       
+                       switch (c){
+                       case 'F': case 'f':
+                               t =  Token.LITERAL_SINGLE;
+                               break;
+                       case 'R': case 'r':
+                               t = Token.LITERAL_DOUBLE;
+                               break;
+                       case 'D': case 'd':
+                                t= Token.LITERAL_DECIMAL;
+                               break;
+                       default:
+                               return Token.NONE;
+                       }
+                       getChar ();
+                       return t;
+               }
+
+               int integer_type_suffix (int c)
+               {
+                       int t;
+                       
+                       try {
+                       
+                               switch (c){
+                               case 'S': case 's':
+                                       t =  Token.LITERAL_INTEGER; // SHORT ?
+                                       val = ((IConvertible)val).ToInt16(null);
+                                       break;
+                               case 'I': case 'i':
+                                       t = Token.LITERAL_INTEGER;
+                                       val = ((IConvertible)val).ToInt32(null);
+                                       break;
+                               case 'L': case 'l':
+                                        t= Token.LITERAL_INTEGER; // LONG ?
+                                        val = ((IConvertible)val).ToInt64(null);
+                                       break;
+                               default:
+                                       if ((long)val <= System.Int32.MaxValue &&
+                                               (long)val >= System.Int32.MinValue) {
+                                               val = ((IConvertible)val).ToInt32(null);
+                                               return Token.LITERAL_INTEGER;
+                                       } else {
+                                               val = ((IConvertible)val).ToInt64(null);
+                                               return Token.LITERAL_INTEGER; // LONG ?
+                                       }
+                               }
+                               getChar ();
+                               return t;
+                       } catch (Exception e) {
+                               val = e.ToString();
+                               return Token.ERROR;
+                       }
+               }
+               
+               int adjust_real (int t)
+               {
+                       string s = number.ToString ();
+
+                       switch (t){
+                       case Token.LITERAL_DECIMAL:
+                               val = new System.Decimal ();
+                               val = System.Decimal.Parse (
+                                       s, styles, csharp_format_info);
+                               break;
+                       case Token.LITERAL_DOUBLE:
+                               val = new System.Double ();
+                               val = System.Double.Parse (
+                                       s, styles, csharp_format_info);
+                               break;
+                       case Token.LITERAL_SINGLE:
+                               val = new System.Double ();
+                               val = (float) System.Double.Parse (
+                                       s, styles, csharp_format_info);
+                               break;
+
+                       case Token.NONE:
+                               val = new System.Double ();
+                               val = System.Double.Parse (
+                                       s, styles, csharp_format_info);
+                               t = Token.LITERAL_DOUBLE;
+                               break;
+                       }
+                       return t;
+               }
+
+               long hex_digits ()
+               {
+                       StringBuilder hexNumber = new StringBuilder ();
+                       
+                       int d;
+
+                       while ((d = peekChar ()) != -1){
+                               char e = Char.ToUpper ((char) d);
+                               
+                               if (Char.IsDigit (e) || (e >= 'A' && e <= 'F')){
+                                       hexNumber.Append (e);
+                                       getChar ();
+                               } else
+                                       break;
+                       }
+                       return System.Int64.Parse (hexNumber.ToString(), NumberStyles.HexNumber);
+               }
+
+               long octal_digits ()
+               {
+                       long valueToReturn = 0;
+                       
+                       int d;
+
+                       while ((d = peekChar ()) != -1){
+                               char e = (char)d;                       
+                               if (Char.IsDigit (e) && (e < '8')){
+                                       valueToReturn *= 8;
+                                       valueToReturn += (d - (int)'0');
+                                       getChar ();
+                               } else
+                                       break;
+                       }
+                       
+                       return valueToReturn;
+               }
+
+               int handle_integer_literal_in_other_bases(int peek)
+               {
+                       if (peek == 'h' || peek == 'H'){
+                               getChar ();
+                               val = hex_digits ();
+                               return integer_type_suffix (peekChar ());
+                       }
+                       
+                       if (peek == 'o' || peek == 'O'){
+                               getChar ();
+                               val = octal_digits ();
+                               return integer_type_suffix (peekChar ());
+                       }
+                       
+                       return Token.NONE;
+               }
+               
+               //
+               // Invoked if we know we have .digits or digits
+               //
+               int is_number (int c)
+               {
+                       bool is_real = false;
+                       number = new StringBuilder ();
+                       int type;
+
+                       number.Length = 0;
+
+                       if (Char.IsDigit ((char)c)){
+                               decimal_digits (c);
+                               c = peekChar ();
+                       }
+
+                       //
+                       // We need to handle the case of
+                       // "1.1" vs "1.ToString()" (LITERAL_SINGLE vs NUMBER DOT IDENTIFIER)
+                       //
+                       if (c == '.'){
+                               if (decimal_digits (getChar())){
+                                       is_real = true;
+                                       c = peekChar ();
+                               } else {
+                                       putback ('.');
+                                       number.Length -= 1;
+                                       val = System.Int64.Parse(number.ToString());
+                                       return integer_type_suffix('.');
+                               }
+                       }
+                       
+                       if (c == 'e' || c == 'E'){
+                               is_real = true;
+                               number.Append ("e");
+                               getChar ();
+                               
+                               c = peekChar ();
+                               if (c == '+'){
+                                       number.Append ((char) c);
+                                       getChar ();
+                                       c = peekChar ();
+                               } else if (c == '-'){
+                                       number.Append ((char) c);
+                                       getChar ();
+                                       c = peekChar ();
+                               }
+                               decimal_digits (-1);
+                               c = peekChar ();
+                       }
+
+                       type = real_type_suffix (c);
+                       if (type == Token.NONE && !is_real){
+                               val = System.Int64.Parse(number.ToString());
+                               return integer_type_suffix(c);
+                       }
+                       
+                       return adjust_real (type);
+               }
+                       
+               int getChar ()
+               {
+                       if (putback_char != -1){
+                               int x = putback_char;
+                               putback_char = -1;
+
+                               return x;
+                       }
+                       return reader.Read ();
+               }
+
+               int peekChar ()
+               {
+                       if (putback_char != -1)
+                               return putback_char;
+                       return reader.Peek ();
+               }
+
+               void putback (int c)
+               {
+                       if (putback_char != -1)
+                               throw new Exception ("This should not happen putback on putback");
+                       putback_char = c;
+               }
+
+               public bool advance ()
+               {
+                       return current_token != Token.EOF ;
+               }
+
+               public Object Value {
+                       get {
+                               return val;
+                       }
+               }
+
+               public Object value ()
+               {
+                       return val;
+               }
+
+               private bool IsEOL(int currentChar)
+               {
+                       bool retVal;
+                       
+                       if (currentChar ==  0x0D) {
+                               if (peekChar() ==  0x0A) // if it is a CR-LF pair consume LF also
+                                       getChar();
+
+                               retVal = true;
+                       }
+                       else {
+                               retVal = (currentChar ==  -1 || currentChar ==  0x0A || currentChar ==  0x2028 || currentChar ==  0x2029);
+                       }
+
+                       if(retVal) {
+                               nextLine();
+                       }
+
+                       return retVal;
+               }
+
+               private int DropComments()              
+               {
+                       int d;
+                       while (!IsEOL(d = getChar ()))
+                               col++;
+
+                       return Token.EOL;
+               }       
+                       
+               public int token ()
+               {
+                       int lastToken = current_token;
+                       do
+                       {
+                               current_token = xtoken ();
+                               if (current_token == 0) 
+                                       return Token.EOF;
+                               if (current_token == Token.REM)
+                                       current_token = DropComments();
+                       } while (lastToken == Token.EOL && current_token == Token.EOL);
+
+                       return current_token;
+               }
+
+               private string GetIdentifier()
+               {
+                       int c = getChar();
+                       if (is_identifier_start_character ((char) c))
+                               return GetIdentifier(c);
+                       else
+                               return null;
+               }
+
+               private string GetIdentifier(int c)
+               {
+                       StringBuilder id = new StringBuilder ();
+
+                       id.Append ((char) c);
+                               
+                       while ((c = peekChar ()) != -1) 
+                       {
+                               if (is_identifier_part_character ((char) c))
+                               {
+                                       id.Append ((char)getChar ());
+                                       col++;
+                               } 
+                               else 
+                                       break;
+                       }
+                       
+                       cant_have_a_type_character = false;
+                       
+                       return id.ToString();
+               }
+
+               private bool is_doublequote(int currentChar)
+               {
+                       return (currentChar == '"' || 
+                                       currentChar == 0x201C || // unicode left double-quote character
+                                       currentChar == 0x201D);  // unicode right double-quote character
+               }
+               
+               private bool is_whitespace(int c)
+               {
+                       return (c == ' ' || c == '\t' || c == '\v' || c == '\r' || c == 0xa0);
+               }
+               
+               private bool tokens_seen = false;
+               
+               private void nextLine()
+               {
+                       cant_have_a_type_character = true;
+                       line++;
+                       ref_line++;
+                       col = 0;
+                       tokens_seen = false;
+               }
+
+               public int xtoken ()
+               {
+                       int t;
+                       bool doread = false;
+                       int c;
+
+                       val = null;
+                       for (;(c = getChar ()) != -1; col++) {
+                       
+                               // Handle line continuation character
+                               if (c == '_') 
+                               {
+                                       int d = peekChar();
+                                       if (!is_identifier_part_character((char)d)) {
+                                               while ((c = getChar ()) != -1 && !IsEOL(c)) {}
+                                               c = getChar ();                 
+                                       }               
+                               }
+
+                               // white space
+                               if (is_whitespace(c)) {
+                                       // expand tabs for location
+                                       if (c == '\t')
+                                               col = (((col + ExpandedTabsSize) / ExpandedTabsSize) * ExpandedTabsSize) - 1;
+                                       cant_have_a_type_character = true;
+                                       continue;
+                               }
+                               
+                               // Handle line comments.
+                               if (c == '\'')
+                                       return Token.REM;                                       
+                               
+                               // Handle EOL.
+                               if (IsEOL(c))
+                               {
+                                       if (current_token == Token.EOL) // if last token was also EOL keep skipping
+                                               continue;
+                                       return Token.EOL;
+                               }
+                               
+                               // Handle escaped identifiers
+                               if (c == '[')
+                               {
+                                       if ((val = GetIdentifier()) == null)
+                                               break;
+                                       if ((c = getChar()) != ']')
+                                               break;
+                                       tokens_seen = true;
+                                       return Token.IDENTIFIER;
+                               }
+
+                               // Handle unescaped identifiers
+                               if (is_identifier_start_character ((char) c))
+                               {
+                                       string id;
+                                       if ((id = GetIdentifier(c)) == null)
+                                               break;
+                                       val = id;
+                                       tokens_seen = true;
+                                       if (is_keyword(id) && (current_token != Token.DOT))
+                                               return getKeyword(id);
+                                       return Token.IDENTIFIER;
+                               }
+
+                               // Treat string literals
+                               if (is_doublequote(c)) {
+                                       cant_have_a_type_character = true;
+                                       return ExtractStringOrCharLiteral(c);
+                               }
+                       
+                               // handle numeric literals
+                               if (c == '.')
+                               {
+                                       cant_have_a_type_character = true;
+                                       tokens_seen = true;
+                                       if (Char.IsDigit ((char) peekChar ()))
+                                               return is_number (c);
+                                       return Token.DOT;
+                               }
+                               
+                               if (Char.IsDigit ((char) c))
+                               {
+                                       cant_have_a_type_character = true;
+                                       tokens_seen = true;
+                                       return is_number (c);
+                               }
+
+                               if ((t = is_punct ((char)c, ref doread)) != Token.ERROR) {
+                                       cant_have_a_type_character = true;
+
+                                       if (t == Token.NONE)
+                                               continue;
+                                               
+                                       if (doread){
+                                               getChar ();
+                                               col++;
+                                       }
+                                       tokens_seen = true;
+                                       return t;
+                               }
+                               
+                               error_details = ((char)c).ToString ();
+                               return Token.ERROR;
+                       }
+
+                       if (current_token != Token.EOL) // if last token wasn't EOL send it before EOF
+                               return Token.EOL;
+                       
+                       return Token.EOF;
+               }
+
+               private int ExtractDateTimeLiteral()
+               {
+                       int c;
+                       
+                       StringBuilder sb = new StringBuilder();
+                       for (;(c = getChar ()) != -1; col++)
+                       {
+                               if (c == '#') {
+                                       val = ParseDateLiteral(sb);
+                                       return Token.LITERAL_DATE;
+                               }
+                               if (IsEOL(c)) {
+                                       break;
+                               } 
+                               if (c == '-')
+                                       c = '/';
+                               sb.Append((char)c);
+                       }
+                       return Token.ERROR;
+               }
+               
+               private int ExtractStringOrCharLiteral(int c)
+               {
+                       StringBuilder s = new StringBuilder ();
+
+                       tokens_seen = true;
+
+                       while ((c = getChar ()) != -1){
+                               if (is_doublequote(c)){
+                                       if (is_doublequote(peekChar()))
+                                               getChar();
+                                       else {
+                                               //handle Char Literals
+                                               if (peekChar() == 'C' || peekChar() == 'c') {
+                                                       getChar();
+                                                       if (s.Length == 1) {
+                                                               val = s[0];
+                                                               return Token.LITERAL_CHARACTER;
+                                                       } else {
+                                                               val = "Incorrect length for a character literal";
+                                                               return Token.ERROR;
+                                                       }                                                       
+                                               } else {
+                                                       val = s.ToString ();
+                                                       return Token.LITERAL_STRING;
+                                               }
+                                       }
+                               }
+
+                               if (IsEOL(c)) {
+                                       return Token.ERROR;
+                               }
+                       
+                               s.Append ((char) c);
+                       }
+                                       
+                       return Token.ERROR;
+               }
+
+               static IFormatProvider enUSculture = new CultureInfo("en-US", true);
+
+               private DateTime ParseDateLiteral(StringBuilder value)
+               {
+                       try
+                       {
+                               return DateTime.Parse(value.ToString(),
+                                                 enUSculture,
+                                                 DateTimeStyles.NoCurrentDateDefault | DateTimeStyles.AllowWhiteSpaces);
+                       }
+                       catch (FormatException ex)
+                       {
+                               //TODO: What is the correct error number and message?
+                               Report.Error (1, Location, string.Format("Invalid date literal '{0}'", value.ToString()) 
+                                       + Environment.NewLine + ex.ToString());
+                       }
+                       catch (Exception)
+                       {
+                               Report.Error (1, Location, "Error parsing date literal");       //TODO: What is the correct error number and message?
+                       }
+                       return new DateTime();
+               }
+               public void PositionCursorAtNextPreProcessorDirective()
+               {
+                       int t;
+                       
+                       for(t = token(); t != Token.HASH && t != Token.EOF; t = token());
+
+                       if(t == Token.EOF)
+                               throw new ApplicationException("Unexpected EOF while looking for a pre-processor directive");
+                       
+                       if(t == Token.HASH) {
+                               tokens_seen = false;
+                               putback('#');
+                       }
+               }
+
+       }
+}