llvm-tutorial/source/Lexer.h

#ifndef LEXER_H
#define LEXER_H

#include <cctype>
#include <cstdio>
#include <map>
#include <string>
#include <vector>
#include "Ast.h"

namespace lexer{
// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
// of these for known things.
enum Token {
  tok_eof = -1,

  // commands
  tok_def = -2,
  tok_extern = -3,

  // primary
  tok_identifier = -4,
  tok_number = -5
};

static std::string IdentifierStr; // Filled in if tok_identifier
static double NumVal;

int gettok();
}

#endif