var DefaultConfig = Config{
	StartLevel: 2,
	EndLevel:   3,
	Ordered:    false,
}

var Empty = &Fragments{
	Headings:    Headings{},
	HeadingsMap: map[string]*Heading{},
}

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

type Config struct {
	// Heading start level to include in the table of contents, starting
	// at h1 (inclusive).
	// <docsmeta>{ "identifiers": ["h1"] }</docsmeta>
	StartLevel int

	// Heading end level, inclusive, to include in the table of contents.
	// Default is 3, a value of -1 will include everything.
	EndLevel int

	// Whether to produce a ordered list or not.
	Ordered bool
}

type Fragments struct {
	// Headings holds the top level headings.
	Headings Headings

	// Identifiers holds all the identifiers in the ToC as a sorted slice.
	// Note that collections.SortedStringSlice has both a Contains and Count method
	// that can be used to identify missing and duplicate IDs.
	Identifiers collections.SortedStringSlice

	// HeadingsMap holds all the headings in the ToC as a map.
	// Note that with duplicate IDs, the last one will win.
	HeadingsMap map[string]*Heading
}

type Heading struct {
	ID    string
	Level int
	Title string

	Headings Headings
}

type Headings []*Heading