/++
  Author: Aziz Köksal
  License: GPL2
+/
module Token;

struct Position
{
  size_t loc;
  size_t col;
}

enum TOK
{
  Identifier,
  Comment,
  String,
  Character,

  // Numbers
  Number,
  Int32, Int64, Uint32, Uint64,


  // Brackets
  LParen,
  RParen,
  LBracket,
  RBracket,
  LBrace,
  RBrace,

  Dot, Slice, Ellipses,

  // Floating point operators
  Unordered,
  UorE,
  UorG,
  UorGorE,
  UorL,
  UorLorE,
  LorEorG,
  LorG,

  // Normal operators
  Assign, Equal, NotEqual, Not,
  LessEqual, Less,
  GreaterEqual, Greater,
  LShiftAssign, LShift,
  RShiftAssign,RShift,
  URShiftAssign, URShift,
  OrAssign, OrLogical, OrBinary,
  AndAssign, AndLogical, AndBinary,
  PlusAssign, PlusPlus, Plus,
  MinusAssign, MinusMinus, Minus,
  DivAssign, Div,
  MulAssign, Mul,
  ModAssign, Mod,
  XorAssign, Xor,
  CatAssign, Catenate,
  Tilde,

  Colon,
  Semicolon,
  Question,
  Comma,
  Dollar,

  /* Keywords:
     NB.: Token.isKeyword() depends on this list being contiguous.
  */
  Abstract,Alias,Align,Asm,Assert,Auto,Body,
  Bool,Break,Byte,Case,Cast,Catch,Cdouble,
  Cent,Cfloat,Char,Class,Const,Continue,Creal,
  Dchar,Debug,Default,Delegate,Delete,Deprecated,Do,
  Double,Else,Enum,Export,Extern,False,Final,
  Finally,Float,For,Foreach,Foreach_reverse,Function,Goto,
  Idouble,If,Ifloat,Import,In,Inout,Int,
  Interface,Invariant,Ireal,Is,Lazy,Long,Macro,
  Mixin,Module,New,Null,Out,Override,Package,
  Pragma,Private,Protected,Public,Real,Ref,Return,
  Scope,Short,Static,Struct,Super,Switch,Synchronized,
  Template,This,Throw,True,Try,Typedef,Typeid,
  Typeof,Ubyte,Ucent,Uint,Ulong,Union,Unittest,
  Ushort,Version,Void,Volatile,Wchar,While,With,

  EOF
}

alias TOK.Abstract KeywordsBegin;
alias TOK.With KeywordsEnd;

struct Token
{
  TOK type;
  Position pos;

  char* start;
  char* end;

  union
  {
    struct
    {
      string str;
      char pf;
    }
    dchar dchar_;
    long  long_;
    ulong ulong_;
    int   int_;
    uint  uint_;
    float f;
    double d;
  }

  string span()
  {
    assert(start && end);
    return start[0 .. end - start];
  }

  bool isKeyword()
  {
    if (KeywordsBegin <= type && type <= KeywordsEnd)
      return true;
    return false;
  }
}