const (
	// ErrInvalidCapacity is returned when the provided capacity is less than 1.
	//
	// This error is not used by the package itself, but is exported for use by
	// packages implementing the Cache interface.
	ErrInvalidCapacity xerrors.Error = "invalid capacity"

	// ErrUnexpectedType is returned when the cache encounters an unexpected
	// type in the list.
	//
	// This error is not used by the package itself, but is exported for use by
	// packages implementing the Cache interface.
	ErrUnexpectedType xerrors.Error = "unexpected type found in the list: expected *recache.Entry"

	// ErrNotFound is returned when a regular expression is not found in the
	// cache.
	//
	// This error is not used by the package itself, but is exported for use by
	// packages implementing the Cache interface.
	ErrNotFound xerrors.Error = "not found in the cache"
)

const DefaultCapacity int = 25

const ErrInvalidEntry xerrors.Error = "invalid entry"

type Cache interface {
	// Get returns a compiled regular expression from the cache given a pattern
	// and an optional flag.
	Get(ctx context.Context, pattern string, flag Flag) (*regexp.Regexp, error)

	// SetCapacity sets the maximum number of regular expressions that can be
	// stored in the cache.
	SetCapacity(capacity int) error

	// Capacity returns the maximum number of regular expressions that can be
	// stored in the cache.
	Capacity() int

	// Size returns the number of regular expressions currently stored in the
	// cache.
	Size() int

	// Clear removes all regular expressions from the cache.
	Clear()
}

type Entry struct {
	// contains filtered or unexported fields
}

type Flag int

const (
	// DefaultFlag is the default flag used when compiling regular expressions.
	DefaultFlag Flag = 0

	// FlagPOSIX specifies that the regular expression should be restricted to
	// POSIX syntax.
	FlagPOSIX Flag = 1 << iota

	// FlagMust specifies that the regular expression should be compiled using
	// MustCompile.
	FlagMust

	// FlagMustPOSIX is like Must but restricts the regular expression to POSIX
	// syntax.
	FlagMustPOSIX = FlagMust | FlagPOSIX
)