regex.h

#ifndef SOURCEMETA_CORE_REGEX_H_
#define SOURCEMETA_CORE_REGEX_H_
 
#ifndef SOURCEMETA_CORE_REGEX_EXPORT
#include <sourcemeta/core/regex_export.h>
#endif
 
#include <cstddef>     // std::size_t
#include <cstdint>     // std::uint8_t
#include <memory>      // std::shared_ptr
#include <optional>    // std::optional
#include <string>      // std::string
#include <string_view> // std::string_view
#include <utility>     // std::pair
#include <variant>     // std::variant

 
namespace sourcemeta::core {

using RegexTypePrefix = std::string;

struct RegexTypeNonEmpty {
  auto operator==(const RegexTypeNonEmpty &) const noexcept -> bool = default;
};

using RegexTypeRange = std::pair<std::size_t, std::size_t>;

struct RegexTypePCRE2 {
  std::shared_ptr<void> code;
  auto operator==(const RegexTypePCRE2 &other) const noexcept -> bool {
    return this->code == other.code;
  }
};

struct RegexTypeNoop {
  auto operator==(const RegexTypeNoop &) const noexcept -> bool = default;
};

using Regex = std::variant<RegexTypePrefix, RegexTypeNonEmpty, RegexTypeRange,
                           RegexTypePCRE2, RegexTypeNoop>;
#if !defined(DOXYGEN)
// For fast internal dispatching. It must stay in sync with the variant above
enum class RegexIndex : std::uint8_t {
  Prefix = 0,
  NonEmpty,
  Range,
  PCRE2,
  Noop
};
#endif

enum class RegexDialect : std::uint8_t {
  Permissive,
  IRegexp,
  IRegexpSearch
};

SOURCEMETA_CORE_REGEX_EXPORT
auto to_regex(const std::string_view pattern,
              const RegexDialect dialect = RegexDialect::Permissive,
              const bool optimise_for_match = true) -> std::optional<Regex>;

SOURCEMETA_CORE_REGEX_EXPORT
auto matches(const Regex &regex, const std::string_view value) -> bool;

SOURCEMETA_CORE_REGEX_EXPORT
auto matches_if_valid(const std::string_view pattern,
                      const std::string_view value,
                      const RegexDialect dialect = RegexDialect::Permissive)
    -> bool;

SOURCEMETA_CORE_REGEX_EXPORT
auto replace_all(const Regex &regex, const std::string_view subject,
                 const std::string_view replacement) -> std::string;

SOURCEMETA_CORE_REGEX_EXPORT
auto is_regex_ecma(const std::string_view pattern) -> bool;
 
} // namespace sourcemeta::core
 
#endif