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# This class implements a pretty printing algorithm. It finds line breaks and
# nice indentations for grouped structure.
#
# By default, the class assumes that primitive elements are strings and each
# byte in the strings have single column in width. But it can be used for other
# situations by giving suitable arguments for some methods:
# *   newline object and space generation block for PrettyPrint.new
# *   optional width argument for PrettyPrint#text
# *   PrettyPrint#breakable
#
#
# There are several candidate uses:
# *   text formatting using proportional fonts
# *   multibyte characters which has columns different to number of bytes
# *   non-string formatting
#
#
# ## Bugs
# *   Box based formatting?
# *   Other (better) model/algorithm?
#
#
# Report any bugs at http://bugs.ruby-lang.org
#
# ## References
# Christian Lindig, Strictly Pretty, March 2000,
# http://www.st.cs.uni-sb.de/~lindig/papers/#pretty
#
# Philip Wadler, A prettier printer, March 1998,
# http://homepages.inf.ed.ac.uk/wadler/topics/language-design.html#prettier
#
# ## Author
# Tanaka Akira <akr@fsij.org>
class PrettyPrint
  interface _Output
    def <<: (String) -> void
  end

  # This is a convenience method which is same as follows:
  #
  #     begin
  #       q = PrettyPrint.new(output, maxwidth, newline, &genspace)
  #       ...
  #       q.flush
  #       output
  #     end
  #
  def self.format: (?untyped output, ?Integer maxwidth, ?String newline, ?^(Integer) -> Integer genspace) { (PrettyPrint) -> untyped } -> _Output

  # This is similar to PrettyPrint::format but the result has no breaks.
  #
  # `maxwidth`, `newline` and `genspace` are ignored.
  #
  # The invocation of `breakable` in the block doesn't break a line and is treated
  # as just an invocation of `text`.
  #
  def self.singleline_format: (?untyped output, ?Integer? maxwidth, ?String? newline, ?^(Integer) -> Integer? genspace ) { (PrettyPrint::SingleLine) -> untyped } -> _Output

  # Creates a buffer for pretty printing.
  #
  # `output` is an output target. If it is not specified, '' is assumed. It should
  # have a << method which accepts the first argument `obj` of PrettyPrint#text,
  # the first argument `sep` of PrettyPrint#breakable, the first argument
  # `newline` of PrettyPrint.new, and the result of a given block for
  # PrettyPrint.new.
  #
  # `maxwidth` specifies maximum line length. If it is not specified, 79 is
  # assumed. However actual outputs may overflow `maxwidth` if long non-breakable
  # texts are provided.
  #
  # `newline` is used for line breaks. "n" is used if it is not specified.
  #
  # The block is used to generate spaces. {|width| ' ' * width} is used if it is
  # not given.
  #
  def initialize: (?untyped output, ?Integer maxwidth, ?String newline, ?^(Integer) -> Integer genspace)  -> void

  # The output object.
  #
  # This defaults to '', and should accept the << method
  attr_reader output: _Output

  # The maximum width of a line, before it is separated in to a newline
  #
  # This defaults to 79, and should be a Fixnum
  attr_reader maxwidth: Integer

  # The value that is appended to +output+ to add a new line.
  #
  # This defaults to "\n", and should be String
  attr_reader newline: String

  # A lambda or Proc, that takes one argument, of a Fixnum, and returns
  # the corresponding number of spaces.
  #
  # By default this is:
  #   lambda {|n| ' ' * n}
  attr_reader genspace: Proc

  # The number of spaces to be indented
  attr_reader indent: Integer

  # The PrettyPrint::GroupQueue of groups in stack to be pretty printed
  attr_reader group_queue: PrettyPrint::GroupQueue

  # Returns the group most recently added to the stack.
  #
  # Contrived example:
  #     out = ""
  #     => ""
  #     q = PrettyPrint.new(out)
  #     => #<PrettyPrint:0x82f85c0 @output="", @maxwidth=79, @newline="\n", @genspace=#<Proc:0x82f8368@/home/vbatts/.rvm/rubies/ruby-head/lib/ruby/2.0.0/prettyprint.rb:82 (lambda)>, @output_width=0, @buffer_width=0, @buffer=[], @group_stack=[#<PrettyPrint::Group:0x82f8138 @depth=0, @breakables=[], @break=false>], @group_queue=#<PrettyPrint::GroupQueue:0x82fb7c0 @queue=[[#<PrettyPrint::Group:0x82f8138 @depth=0, @breakables=[], @break=false>]]>, @indent=0>
  #     q.group {
  #       q.text q.current_group.inspect
  #       q.text q.newline
  #       q.group(q.current_group.depth + 1) {
  #         q.text q.current_group.inspect
  #         q.text q.newline
  #         q.group(q.current_group.depth + 1) {
  #           q.text q.current_group.inspect
  #           q.text q.newline
  #           q.group(q.current_group.depth + 1) {
  #             q.text q.current_group.inspect
  #             q.text q.newline
  #           }
  #         }
  #       }
  #     }
  #     => 284
  #      puts out
  #     #<PrettyPrint::Group:0x8354758 @depth=1, @breakables=[], @break=false>
  #     #<PrettyPrint::Group:0x8354550 @depth=2, @breakables=[], @break=false>
  #     #<PrettyPrint::Group:0x83541cc @depth=3, @breakables=[], @break=false>
  #     #<PrettyPrint::Group:0x8347e54 @depth=4, @breakables=[], @break=false>
  #
  def current_group: () -> PrettyPrint::Group

  # Breaks the buffer into lines that are shorter than #maxwidth
  #
    def break_outmost_groups: () -> untyped

  # This adds `obj` as a text of `width` columns in width.
  #
  # If `width` is not specified, obj.length is used.
  #
  def text: (String obj, ?Integer width) -> void

  # This is similar to #breakable except the decision to break or not is
  # determined individually.
  #
  # Two #fill_breakable under a group may cause 4 results: (break,break),
  # (break,non-break), (non-break,break), (non-break,non-break). This is different
  # to #breakable because two #breakable under a group may cause 2 results:
  # (break,break), (non-break,non-break).
  #
  # The text `sep` is inserted if a line is not broken at this point.
  #
  # If `sep` is not specified, " " is used.
  #
  # If `width` is not specified, `sep.length` is used. You will have to specify
  # this when `sep` is a multibyte character, for example.
  #
  def fill_breakable: (?String sep, ?Integer width) -> void

  # This says "you can break a line here if necessary", and a `width`-column text
  # `sep` is inserted if a line is not broken at the point.
  #
  # If `sep` is not specified, " " is used.
  #
  # If `width` is not specified, `sep.length` is used. You will have to specify
  # this when `sep` is a multibyte character, for example.
  #
  def breakable: (?String sep, ?Integer width) -> void

  # Groups line break hints added in the block. The line break hints are all to be
  # used or not.
  #
  # If `indent` is specified, the method call is regarded as nested by
  # nest(indent) { ... }.
  #
  # If `open_obj` is specified, `text open_obj, open_width` is called before
  # grouping. If `close_obj` is specified, `text close_obj, close_width` is called
  # after grouping.
  #
  def group: (?::Integer indent, ?::String open_obj, ?::String close_obj, ?Integer open_width, ?Integer close_width) { () -> untyped } -> Integer

  # Takes a block and queues a new group that is indented 1 level further.
  #
  def group_sub: () { () -> untyped } -> untyped

  # Increases left margin after newline with `indent` for line breaks added in the
  # block.
  #
  def nest: (Integer indent) { () -> untyped } -> void

  # outputs buffered data.
  #
  def flush: () -> Integer

  class Text
    # Creates a new text object.
    #
    # This constructor takes no arguments.
    #
    # The workflow is to append a PrettyPrint::Text object to the buffer, and
    # being able to call the buffer.last() to reference it.
    #
    # As there are objects, use PrettyPrint::Text#add to include the objects
    # and the width to utilized by the String version of this object.
    def initialize: () -> void

    # The total width of the objects included in this Text object.
    attr_reader width: Integer

    # Render the String text of the objects that have been added to this Text object.
    #
    # Output the text to +out+, and increment the width to +output_width+
    def output: (untyped `out`, untyped output_width) -> untyped

    # Include +obj+ in the objects to be pretty printed, and increment
    # this Text object's total width by +width+
    def add: (untyped obj, Integer width) -> void
  end

  class Breakable
    # Create a new Breakable object.
    #
    # Arguments:
    # * +sep+ String of the separator
    # * +width+ Fixnum width of the +sep+
    # * +q+ parent PrettyPrint object, to base from
    def initialize: (String sep, Integer width, PrettyPrint q) -> void

    # Holds the separator String
    #
    # The +sep+ argument from ::new
    attr_reader obj: String

    # The width of +obj+ / +sep+
    attr_reader width: Integer

    # The number of spaces to indent.
    #
    # This is inferred from +q+ within PrettyPrint, passed in ::new
    attr_reader indent: Integer

    # Render the String text of the objects that have been added to this
    # Breakable object.
    #
    # Output the text to +out+, and increment the width to +output_width+
    def output: (untyped `out`, Integer output_width) -> untyped
  end

  class Group
    # The Group class is used for making indentation easier.
    #
    # While this class does neither the breaking into newlines nor indentation,
    # it is used in a stack (as well as a queue) within PrettyPrint, to group
    # objects.
    #
    # For information on using groups, see PrettyPrint#group
    #
    # This class is intended for internal use of the PrettyPrint buffers.
    # :nodoc:
    # Create a Group object
    #
    # Arguments:
    # * +depth+ - this group's relation to previous groups
    def initialize: (untyped depth) -> void

    # This group's relation to previous groups
    attr_reader depth: untyped

    # Array to hold the Breakable objects for this Group
    attr_reader breakables: Array[PrettyPrint::Breakable]

    # Makes a break for this Group, and returns true
    def break: () -> bool

    # Boolean of whether this Group has made a break
    def break?: () -> bool

    # Boolean of whether this Group has been queried for being first
    #
    # This is used as a predicate, and ought to be called first.
    def first?: () -> bool
  end

  class GroupQueue
    # The GroupQueue class is used for managing the queue of Group to be pretty
    # printed.
    #
    # This queue groups the Group objects, based on their depth.
    #
    # This class is intended for internal use of the PrettyPrint buffers.
    # :nodoc:
    # Create a GroupQueue object
    #
    # Arguments:
    # * +groups+ - one or more PrettyPrint::Group objects
    def initialize: (*untyped groups) -> void

    # Enqueue +group+
    #
    # This does not strictly append the group to the end of the queue,
    # but instead adds it in line, base on the +group.depth+
    def enq: (untyped group) -> void

    # Returns the outer group of the queue
    def deq: () -> (PrettyPrint::Group | nil)

    # Remote +group+ from this queue
    def delete: (PrettyPrint::Group group) -> void
  end

  # PrettyPrint::SingleLine is used by PrettyPrint.singleline_format
  #
  # It is passed to be similar to a PrettyPrint object itself, by responding to:
  # * #text
  # * #breakable
  # * #nest
  # * #group
  # * #flush
  # * #first?
  #
  # but instead, the output has no line breaks
  #
  class SingleLine
    # Create a PrettyPrint::SingleLine object
    #
    # Arguments:
    # * +output+ - String (or similar) to store rendered text. Needs to respond to '<<'
    # * +maxwidth+ - Argument position expected to be here for compatibility.
    #                This argument is a noop.
    # * +newline+ - Argument position expected to be here for compatibility.
    #               This argument is a noop.
    def initialize: (String | untyped output, ?Integer? maxwidth, ?String? newline) -> void

    # Add +obj+ to the text to be output.
    #
    # +width+ argument is here for compatibility. It is a noop argument.
    def text: (String obj, ?Integer? width) -> void

    # Appends +sep+ to the text to be output. By default +sep+ is ' '
    #
    # +width+ argument is here for compatibility. It is a noop argument.
    def breakable: (?String sep, ?Integer? width) -> void

    def nest: (untyped indent) { () -> untyped } -> void

    # Opens a block for grouping objects to be pretty printed.
    #
    # Arguments:
    # * +indent+ - noop argument. Present for compatibility.
    # * +open_obj+ - text appended before the &blok. Default is ''
    # * +close_obj+ - text appended after the &blok. Default is ''
    # * +open_width+ - noop argument. Present for compatibility.
    # * +close_width+ - noop argument. Present for compatibility.
    def group: (?Integer? indent, ?String open_obj, ?String close_obj, ?Integer? open_width, ?Integer? close_width) { () -> untyped } -> untyped

    def flush: () -> nil

    # This is used as a predicate, and ought to be called first.
    def first?: () -> bool
  end
end