joko/lib/Lexer.hpp

#ifndef jk_LEXER_HPP
#define jk_LEXER_HPP

#include "commons.hpp"
#include "Logger.hpp"
#include "Node.hpp"

namespace jk
{
  JK_ERROR(lexical_error);

  struct ScanInfo {
    size_t cursor;
    NodeType type;
    std::string repr;
  };

  using scanner_t = std::function<std::optional<ScanInfo>()>;

  class Lexer
  {
  public:
    explicit Lexer(Logger& logger, Loc const& loc);
    virtual ~Lexer();

    Loc loc() const { return m_loc; }

    void scan(std::string const& source);
    std::shared_ptr<Node> next();

  private:
    Logger& m_logger;
    Loc m_loc;
    size_t m_cursor;
    std::string m_source;
    std::vector<scanner_t> m_scanners;

    bool more(size_t index) const;
    char at(size_t index) const;

    void skip_spaces();

    std::optional<ScanInfo> scan_int() const;
    std::optional<ScanInfo> scan_text(NodeType type,
                                      std::string const& text,
                                      bool has_value) const;
    std::optional<ScanInfo> scan_ident() const;
  };
}

#endif