protoprint

type CommentType int

type Element interface {
	// Kind returns the kind of the element. The kind determines which other
	// methods are applicable.
	Kind() ElementKind
	// Name returns the element name. This is NOT applicable to syntax,
	// extension range, and reserved range kinds and will return the empty
	// string for these kinds. For custom options, this will be the
	// fully-qualified name of the corresponding extension.
	Name() string
	// Number returns the element number. This is only applicable to field,
	// extension, and enum value kinds and will return zero for all other kinds.
	Number() int32
	// NumberRange returns the range of numbers/tags for the element. This is
	// only applicable to extension ranges and reserved ranges and will return
	// (0, 0) for all other kinds.
	NumberRange() (int32, int32)
	// Extendee is the extended message for the extension element. Elements
	// other than extensions will return the empty string.
	Extendee() string
	// IsCustomOption returns true if the element is a custom option. If it is
	// not (including if the element kind is not option) then this method will
	// return false.
	IsCustomOption() bool
}

type ElementKind int

type Printer struct {
	// If true, comments are rendered using "/*" style comments. Otherwise, they
	// are printed using "//" style line comments.
	PreferMultiLineStyleComments bool

	// If true, elements are sorted into a canonical order.
	//
	// The canonical order for elements in a file follows:
	//  1. Syntax
	//  2. Package
	//  3. Imports (sorted lexically)
	//  4. Options (sorted by name, standard options before custom options)
	//  5. Messages (sorted by name)
	//  6. Enums (sorted by name)
	//  7. Services (sorted by name)
	//  8. Extensions (grouped by extendee, sorted by extendee+tag)
	//
	// The canonical order of elements in a message follows:
	//  1. Options (sorted by name, standard options before custom options)
	//  2. Fields and One-Ofs (sorted by tag; one-ofs interleaved based on the
	//     minimum tag therein)
	//  3. Nested Messages (sorted by name)
	//  4. Nested Enums (sorted by name)
	//  5. Extension ranges (sorted by starting tag number)
	//  6. Nested Extensions (grouped by extendee, sorted by extendee+tag)
	//  7. Reserved ranges (sorted by starting tag number)
	//  8. Reserved names (sorted lexically)
	//
	// Methods are sorted within a service by name and appear after any service
	// options (which are sorted by name, standard options before custom ones).
	// Enum values are sorted within an enum, first by numeric value then by
	// name, and also appear after any enum options.
	//
	// Options for fields, enum values, and extension ranges are sorted by name,
	// standard options before custom ones.
	SortElements bool

	// The "less" function used to sort elements when printing. It is given two
	// elements, a and b, and should return true if a is "less than" b. In this
	// case, "less than" means that element a should appear earlier in the file
	// than element b.
	//
	// If this field is nil, no custom sorting is done and the SortElements
	// field is consulted to decide how to order the output. If this field is
	// non-nil, the SortElements field is ignored and this function is called to
	// order elements.
	CustomSortFunction func(a, b Element) bool

	// The indentation used. Any characters other than spaces or tabs will be
	// replaced with spaces. If unset/empty, two spaces will be used.
	Indent string

	// If true, detached comments (between elements) will be ignored.
	//
	// Deprecated: Use OmitComments bitmask instead.
	OmitDetachedComments bool

	// A bitmask of comment types to omit. If unset, all comments will be
	// included. Use CommentsAll to not print any comments.
	OmitComments CommentType

	// If true, trailing comments that typically appear on the same line as an
	// element (option, field, enum value, method) will be printed on a separate
	// line instead.
	//
	// So, with this set, you'll get output like so:
	//
	//    // leading comment for field
	//    repeated string names = 1;
	//    // trailing comment
	//
	// If left false, the printer will try to emit trailing comments on the same
	// line instead:
	//
	//    // leading comment for field
	//    repeated string names = 1; // trailing comment
	//
	// If the trailing comment has more than one line, it will automatically be
	// forced to the next line.
	TrailingCommentsOnSeparateLine bool

	// If true, the printed output will eschew any blank lines, which otherwise
	// appear between descriptor elements and comment blocks. Note that if
	// detached comments are being printed, this will cause them to be merged
	// into the subsequent leading comments. Similarly, any element trailing
	// comments will be merged into the subsequent leading comments.
	Compact bool

	// If true, all references to messages, extensions, and enums (such as in
	// options, field types, and method request and response types) will be
	// fully-qualified. When left unset, the referenced elements will contain
	// only as much qualifier as is required.
	//
	// For example, if a message is in the same package as the reference, the
	// simple name can be used. If a message shares some context with the
	// reference, only the unshared context needs to be included. For example:
	//
	//  message Foo {
	//    message Bar {
	//      enum Baz {
	//        ZERO = 0;
	//        ONE = 1;
	//      }
	//    }
	//
	//    // This field shares some context as the enum it references: they are
	//    // both inside of the namespace Foo:
	//    //    field is "Foo.my_baz"
	//    //     enum is "Foo.Bar.Baz"
	//    // So we only need to qualify the reference with the context that they
	//    // do NOT have in common:
	//    Bar.Baz my_baz = 1;
	//  }
	//
	// When printing fully-qualified names, they will be preceded by a dot, to
	// avoid any ambiguity that they might be relative vs. fully-qualified.
	ForceFullyQualifiedNames bool

	// The number of options that trigger short options expressions to be
	// rendered using multiple lines. Short options expressions are those
	// found on fields and enum values, that use brackets ("[" and "]") and
	// comma-separated options. If more options than this are present, they
	// will be expanded to multiple lines (one option per line).
	//
	// If unset (e.g. if zero), a default threshold of 3 is used.
	ShortOptionsExpansionThresholdCount int

	// The length of printed options that trigger short options expressions to
	// be rendered using multiple lines. If the short options contain more than
	// one option and their printed length is longer than this threshold, they
	// will be expanded to multiple lines (one option per line).
	//
	// If unset (e.g. if zero), a default threshold of 50 is used.
	ShortOptionsExpansionThresholdLength int

	// The length of a printed option value message literal that triggers the
	// message literal to be rendered using multiple lines instead of using a
	// compact single-line form. The message must include at least two fields
	// or contain a field that is a nested message to be expanded.
	//
	// This value is further used to decide when to expand individual field
	// values that are nested message literals or array literals (for repeated
	// fields).
	//
	// If unset (e.g. if zero), a default threshold of 50 is used.
	MessageLiteralExpansionThresholdLength int
}