version 1 .

PreprocessorInput = [@context Context, @book Book] .

Context = {
  "root": @root string,
  "config": @config any,
  "renderer": @renderer string,
  "mdbook_version": @mdbook_version string,
} .

Book = {
  "sections": @sections [BookItem ...],
  "__non_exhaustive": =null,
} .

BookItem =
/ @chapter { "Chapter": @value Chapter }
/ @separator "Separator"
/ @partTitle { "PartTitle": @value string }
.

Chapter = {
  "name": @name string,
  "content": @content string,
  "number": @number MaybeSectionNumber,
  "sub_items": @sub_items [BookItem ...],
  "path": @path MaybePath,
  "source_path": @source_path MaybePath,
  "parent_names": @parent_names [string ...],
} .

MaybeSectionNumber = @absent =null / @present [int ...] .
MaybePath = @absent =null / @present string .