# <!-- rdoc-file=ext/stringio/stringio.c -->
# IO streams for strings, with access similar to [IO](rdoc-ref:IO); see
# [IO](rdoc-ref:IO).
#
# ### About the Examples
#
# Examples on this page assume that StringIO has been required:
#
#     require 'stringio'
#
class StringIO
  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - StringIO.new(string = '', mode = 'r+') -> new_stringio
  # -->
  # Note that `mode` defaults to `'r'` if `string` is frozen.
  #
  # Returns a new StringIO instance formed from `string` and `mode`; see [Access
  # Modes](rdoc-ref:File@Access+Modes):
  #
  #     strio = StringIO.new # => #<StringIO>
  #     strio.close
  #
  # The instance should be closed when no longer needed.
  #
  # Related: StringIO.open (accepts block; closes automatically).
  #
  def initialize: (?String string, ?String? mode) -> void

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - StringIO.open(string = '', mode = 'r+') {|strio| ... }
  # -->
  # Note that `mode` defaults to `'r'` if `string` is frozen.
  #
  # Creates a new StringIO instance formed from `string` and `mode`; see [Access
  # Modes](rdoc-ref:File@Access+Modes).
  #
  # With no block, returns the new instance:
  #
  #     strio = StringIO.open # => #<StringIO>
  #
  # With a block, calls the block with the new instance and returns the block's
  # value; closes the instance on block exit.
  #
  #     StringIO.open {|strio| p strio }
  #     # => #<StringIO>
  #
  # Related: StringIO.new.
  #
  def self.open: [U] (?String string, ?String? mode) { (StringIO arg) -> U } -> U

  def <<: (untyped arg0) -> self

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - binmode -> self
  # -->
  # Sets the data mode in `self` to binary mode; see [Data
  # Mode](rdoc-ref:File@Data+Mode).
  #
  def binmode: () -> self

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - close -> nil
  # -->
  # Closes `self` for both reading and writing.
  #
  # Raises IOError if reading or writing is attempted.
  #
  # Related: StringIO#close_read, StringIO#close_write.
  #
  def close: () -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - close_read -> nil
  # -->
  # Closes `self` for reading; closed-write setting remains unchanged.
  #
  # Raises IOError if reading is attempted.
  #
  # Related: StringIO#close, StringIO#close_write.
  #
  def close_read: () -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - close_write -> nil
  # -->
  # Closes `self` for writing; closed-read setting remains unchanged.
  #
  # Raises IOError if writing is attempted.
  #
  # Related: StringIO#close, StringIO#close_read.
  #
  def close_write: () -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - closed? -> true or false
  # -->
  # Returns `true` if `self` is closed for both reading and writing, `false`
  # otherwise.
  #
  def closed?: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - closed_read? -> true or false
  # -->
  # Returns `true` if `self` is closed for reading, `false` otherwise.
  #
  def closed_read?: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - closed_write? -> true or false
  # -->
  # Returns `true` if `self` is closed for writing, `false` otherwise.
  #
  def closed_write?: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - each_line(sep = $/, chomp: false) {|line| ... }   -> self
  #   - each_line(limit, chomp: false) {|line| ... }      -> self
  #   - each_line(sep, limit, chomp: false) {|line| ... } -> self
  # -->
  # Calls the block with each remaining line read from the stream; does nothing if
  # already at end-of-file; returns `self`. See [Line IO](rdoc-ref:IO@Line+IO).
  #
  # StringIO#each is an alias for StringIO#each_line.
  #
  def each: (?String sep, ?Integer limit, ?chomp: boolish) { (String) -> untyped } -> self
          | (?String sep, ?Integer limit, ?chomp: boolish) -> ::Enumerator[String, self]

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - each_byte {|byte| ... } -> self
  # -->
  # With a block given, calls the block with each remaining byte in the stream;
  # see [Byte IO](rdoc-ref:IO@Byte+IO).
  #
  # With no block given, returns an enumerator.
  #
  def each_byte: () { (Integer arg0) -> untyped } -> self
               | () -> ::Enumerator[Integer, self]

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - each_char {|c| ... } -> self
  # -->
  # With a block given, calls the block with each remaining character in the
  # stream; see [Character IO](rdoc-ref:IO@Character+IO).
  #
  # With no block given, returns an enumerator.
  #
  def each_char: () { (String arg0) -> untyped } -> self
               | () -> ::Enumerator[String, self]

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - each_codepoint {|codepoint| ... } -> self
  # -->
  # With a block given, calls the block with each remaining codepoint in the
  # stream; see [Codepoint IO](rdoc-ref:IO@Codepoint+IO).
  #
  # With no block given, returns an enumerator.
  #
  def each_codepoint: () { (Integer arg0) -> untyped } -> self
                    | () -> ::Enumerator[Integer, self]

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - eof? -> true or false
  # -->
  # Returns `true` if positioned at end-of-stream, `false` otherwise; see
  # [Position](rdoc-ref:File@Position).
  #
  # Raises IOError if the stream is not opened for reading.
  #
  # StreamIO#eof is an alias for StreamIO#eof?.
  #
  def eof: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - fcntl(*args)
  # -->
  # Raises NotImplementedError.
  #
  def fcntl: (Integer integer_cmd, String | Integer arg) -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - fileno()
  # -->
  # Returns `nil`.  Just for compatibility to IO.
  #
  def fileno: () -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - flush()
  # -->
  # Returns an object itself.  Just for compatibility to IO.
  #
  def flush: () -> self

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - fsync()
  # -->
  # Returns 0.  Just for compatibility to IO.
  #
  def fsync: () -> Integer?

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - getbyte -> byte or nil
  # -->
  # Reads and returns the next 8-bit byte from the stream; see [Byte
  # IO](rdoc-ref:IO@Byte+IO).
  #
  def getbyte: () -> Integer?

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - getc -> character or nil
  # -->
  # Reads and returns the next character from the stream; see [Character
  # IO](rdoc-ref:IO@Character+IO).
  #
  def getc: () -> String?

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - gets(sep = $/, chomp: false) -> string or nil
  #   - gets(limit, chomp: false) -> string or nil
  #   - gets(sep, limit, chomp: false) -> string or nil
  # -->
  # Reads and returns a line from the stream; assigns the return value to `$_`;
  # see [Line IO](rdoc-ref:IO@Line+IO).
  #
  def gets: (?String sep, ?Integer limit, ?chomp: boolish) -> String?

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.internal_encoding   => encoding
  # -->
  # Returns the Encoding of the internal string if conversion is specified.
  # Otherwise returns `nil`.
  #
  def internal_encoding: () -> Encoding

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.external_encoding   => encoding
  # -->
  # Returns the Encoding object that represents the encoding of the file. If the
  # stream is write mode and no encoding is specified, returns `nil`.
  #
  def external_encoding: () -> Encoding

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - isatty()
  # -->
  # Returns `false`.  Just for compatibility to IO.
  #
  def isatty: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - lineno -> current_line_number
  # -->
  # Returns the current line number in `self`; see [Line
  # Number](rdoc-ref:IO@Line+Number).
  #
  def lineno: () -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - lineno = new_line_number -> new_line_number
  # -->
  # Sets the current line number in `self` to the given `new_line_number`; see
  # [Line Number](rdoc-ref:IO@Line+Number).
  #
  def lineno=: (Integer arg0) -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - pid()
  # -->
  # Returns `nil`.  Just for compatibility to IO.
  #
  def pid: () -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - pos -> stream_position
  # -->
  # Returns the current position (in bytes); see [Position](rdoc-ref:IO@Position).
  #
  # StringIO#tell is an alias for StringIO#pos.
  #
  def pos: () -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - pos = new_position -> new_position
  # -->
  # Sets the current position (in bytes); see [Position](rdoc-ref:IO@Position).
  #
  def pos=: (Integer arg0) -> Integer

  def print: (*untyped arg0) -> nil

  def printf: (String format_string, *untyped arg0) -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.putc(obj)    -> obj
  # -->
  # See IO#putc.
  #
  def putc: (Numeric | String arg0) -> untyped

  def puts: (*untyped arg0) -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.read([length [, outbuf]])    -> string, outbuf, or nil
  # -->
  # See IO#read.
  #
  def read: (?int? length, ?string outbuf) -> String?

  def read_nonblock: (int len, ?string buf) -> String

  def readbyte: () -> Integer

  def readchar: () -> String

  def readline: (?String sep, ?Integer limit) -> String

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.readlines(sep=$/, chomp: false)     ->   array
  #   - strio.readlines(limit, chomp: false)      ->   array
  #   - strio.readlines(sep, limit, chomp: false) ->   array
  # -->
  # See IO#readlines.
  #
  def readlines: (?String sep, ?Integer limit, ?chomp: boolish) -> ::Array[String]

  def readpartial: (int maxlen, ?string outbuf) -> String

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - reopen(other, mode = 'r+') -> self
  # -->
  # Reinitializes the stream with the given `other` (string or StringIO) and
  # `mode`; see IO.new:
  #
  #     StringIO.open('foo') do |strio|
  #       p strio.string
  #       strio.reopen('bar')
  #       p strio.string
  #       other_strio = StringIO.new('baz')
  #       strio.reopen(other_strio)
  #       p strio.string
  #       other_strio.close
  #     end
  #
  # Output:
  #
  #     "foo"
  #     "bar"
  #     "baz"
  #
  def reopen: (StringIO other) -> self
            | (String other, ?String mode_str) -> self

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - rewind -> 0
  # -->
  # Sets the current position and line number to zero; see
  # [Position](rdoc-ref:IO@Position) and [Line Number](rdoc-ref:IO@Line+Number).
  #
  def rewind: () -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - seek(offset, whence = SEEK_SET) -> 0
  # -->
  # Sets the current position to the given integer `offset` (in bytes), with
  # respect to a given constant `whence`; see [Position](rdoc-ref:IO@Position).
  #
  def seek: (Integer amount, ?Integer whence) -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.set_encoding(ext_enc, [int_enc[, opt]])  => strio
  # -->
  # Specify the encoding of the StringIO as *ext_enc*. Use the default external
  # encoding if *ext_enc* is nil. 2nd argument *int_enc* and optional hash *opt*
  # argument are ignored; they are for API compatibility to IO.
  #
  def set_encoding: (?String | Encoding ext_or_ext_int_enc) -> self
                  | (?String | Encoding ext_or_ext_int_enc, ?String | Encoding int_enc) -> self

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - string -> string
  # -->
  # Returns underlying string:
  #
  #     StringIO.open('foo') do |strio|
  #       p strio.string
  #       strio.string = 'bar'
  #       p strio.string
  #     end
  #
  # Output:
  #
  #     "foo"
  #     "bar"
  #
  # Related: StringIO#string= (assigns the underlying string).
  #
  def string: () -> String

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - string = other_string -> other_string
  # -->
  # Assigns the underlying string as `other_string`, and sets position to zero;
  # returns `other_string`:
  #
  #     StringIO.open('foo') do |strio|
  #       p strio.string
  #       strio.string = 'bar'
  #       p strio.string
  #     end
  #
  # Output:
  #
  #     "foo"
  #     "bar"
  #
  # Related: StringIO#string (returns the underlying string).
  #
  def string=: (String str) -> String

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.length -> integer
  #   - strio.size   -> integer
  # -->
  # Returns the size of the buffer string.
  #
  def size: () -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - sync -> true
  # -->
  # Returns `true`; implemented only for compatibility with other stream classes.
  #
  def sync: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - sync=(p1)
  # -->
  # Returns the argument unchanged.  Just for compatibility to IO.
  #
  def sync=: (boolish) -> bool

  def sysread: (Integer maxlen, String outbuf) -> String

  def syswrite: (String arg0) -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - pos -> stream_position
  # -->
  # Returns the current position (in bytes); see [Position](rdoc-ref:IO@Position).
  #
  # StringIO#tell is an alias for StringIO#pos.
  #
  def tell: () -> Integer

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.truncate(integer)    -> 0
  # -->
  # Truncates the buffer string to at most *integer* bytes. The stream must be
  # opened for writing.
  #
  def truncate: (Integer) -> 0

  # <!-- rdoc-file=ext/stringio/stringio.c -->
  # Returns `false`.  Just for compatibility to IO.
  #
  def tty?: () -> bool

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - ungetbyte(byte) -> nil
  # -->
  # Pushes back ("unshifts") an 8-bit byte onto the stream; see [Byte
  # IO](rdoc-ref:IO@Byte+IO).
  #
  def ungetbyte: (String | Integer arg0) -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - ungetc(character) -> nil
  # -->
  # Pushes back ("unshifts") a character or integer onto the stream; see
  # [Character IO](rdoc-ref:IO@Character+IO).
  #
  def ungetc: (String arg0) -> nil

  # <!--
  #   rdoc-file=ext/stringio/stringio.c
  #   - strio.write(string, ...) -> integer
  #   - strio.syswrite(string)   -> integer
  # -->
  # Appends the given string to the underlying buffer string. The stream must be
  # opened for writing.  If the argument is not a string, it will be converted to
  # a string using `to_s`. Returns the number of bytes written.  See IO#write.
  #
  def write: (*_ToS) -> Integer

  # This is a deprecated alias for #each_byte.
  #
  def bytes: () { (Integer arg0) -> untyped } -> self
           | () -> ::Enumerator[Integer, self]

  # This is a deprecated alias for #each_char.
  #
  def chars: () { (String arg0) -> untyped } -> self
           | () -> ::Enumerator[String, self]

  # This is a deprecated alias for #each_codepoint.
  #
  def codepoints: () { (Integer arg0) -> untyped } -> self
                | () -> ::Enumerator[Integer, self]

  # <!-- rdoc-file=ext/stringio/stringio.c -->
  # Calls the block with each remaining line read from the stream; does nothing if
  # already at end-of-file; returns `self`. See [Line IO](rdoc-ref:IO@Line+IO).
  #
  # StringIO#each is an alias for StringIO#each_line.
  #
  def each_line: (?String sep, ?Integer limit, ?chomp: boolish) { (String) -> untyped } -> self
               | (?String sep, ?Integer limit, ?chomp: boolish) -> ::Enumerator[String, self]

  # <!-- rdoc-file=ext/stringio/stringio.c -->
  # Returns `true` if positioned at end-of-stream, `false` otherwise; see
  # [Position](rdoc-ref:File@Position).
  #
  # Raises IOError if the stream is not opened for reading.
  #
  # StreamIO#eof is an alias for StreamIO#eof?.
  #
  def eof?: () -> bool

  # This is a deprecated alias for #each_line.
  #
  def lines: (?String sep, ?Integer limit) { (String arg0) -> untyped } -> self
           | (?String sep, ?Integer limit) -> ::Enumerator[String, self]
end