# class Compress::Deflate::Writer

- Compress::Deflate::Writer
- IO
- Reference
- Object

##
Overview

A write-only `IO` object to compress data in the DEFLATE format.

Instances of this class wrap another IO object. When you write to this instance, it compresses the data and writes it to the underlying IO.

NOTE unless created with a block, `#close` must be invoked after all data has been written to a Flate::Writer instance.

##
Defined in:

compress/deflate/writer.cr

##
Constructors

- .new(output : IO, level : Int32 = Compress::Deflate::DEFAULT_COMPRESSION, strategy : Compress::Deflate::Strategy = Compress::Deflate::Strategy::DEFAULT, sync_close : Bool = false, dict : Bytes | Nil = nil)

  Creates an instance of Flate::Writer.

##
Class Method Summary

- .open(io : IO, level : Int32 = Compress::Deflate::DEFAULT_COMPRESSION, strategy : Compress::Deflate::Strategy = Compress::Deflate::Strategy::DEFAULT, sync_close : Bool = false, dict : Bytes | Nil = nil, &)

  Creates a new writer for the given io, yields it to the given block, and closes it at its end.

##
Instance Method Summary

- #close : Nil

  Closes this writer.

- #closed? : Bool

  Returns `true` if this IO is closed.

- #flush : Nil

  See `IO#flush`.

- #inspect(io : IO) : Nil

  Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

- #read(slice : Bytes) : NoReturn

  Always raises `IO::Error` because this is a write-only `IO`.

- #sync_close=(sync_close : Bool)

  If `#sync_close?` is `true`, closing this IO will close the underlying IO.

- #sync_close? : Bool

  If `#sync_close?` is `true`, closing this IO will close the underlying IO.

- #write(slice : Bytes) : Nil

  See `IO#write`.

### Instance methods inherited from class `IO`

<<(obj) : self <<, close close, closed? : Bool closed?, each_byte(&) : Nil
each_byte each_byte, each_char(&) : Nil
each_char each_char, each_line(*args, **options, &block : String -> ) : Nil
each_line(*args, **options) each_line, encoding : String encoding, flush flush, getb_to_end : Bytes getb_to_end, gets(limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, chomp = false) : String | Nil
gets(delimiter : String, chomp = false) : String | Nil
gets(chomp = true) : String | Nil gets, gets_to_end : String gets_to_end, peek : Bytes | Nil peek, pos pos, pos=(value) pos=, print(obj : _) : Nil
print(*objects : _) : Nil print, printf(format_string, args : Array | Tuple) : Nil
printf(format_string, *args) : Nil printf, puts(string : String) : Nil
puts(obj : _) : Nil
puts : Nil
puts(*objects : _) : Nil puts, read(slice : Bytes) read, read_at(offset, bytesize, & : IO -> ) read_at, read_byte : UInt8 | Nil read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char | Nil read_char, read_fully(slice : Bytes) : Int32 read_fully, read_fully?(slice : Bytes) : Int32 | Nil read_fully?, read_line(*args, **options) : String read_line, read_string(bytesize : Int) : String read_string, read_utf8(slice : Bytes) read_utf8, read_utf8_byte : UInt8 | Nil read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol | Nil = nil) : Nil set_encoding, skip(bytes_count : Int) : Nil skip, skip_to_end : Nil skip_to_end, tell tell, tty? : Bool tty?, write(slice : Bytes) : Nil write, write_byte(byte : UInt8) : Nil write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) : Nil write_bytes, write_string(slice : Bytes) : Nil write_string, write_utf8(slice : Bytes) : Nil write_utf8

### Class methods inherited from class `IO`

copy(src, dst, limit : Int) : Int64
copy(src, dst) : Int64 copy, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &) pipe, same_content?(stream1 : IO, stream2 : IO) : Bool same_content?

### Instance methods inherited from class `Reference`

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s

### Constructor methods inherited from class `Reference`

new new, unsafe_construct(address : Pointer, *args, **opts) : self unsafe_construct

### Class methods inherited from class `Reference`

pre_initialize(address : Pointer) pre_initialize

### Instance methods inherited from class `Object`

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

### Class methods inherited from class `Object`

from_json(string_or_io, root : String)
from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml

### Macros inherited from class `Object`

class_getter(*names, &block) class_getter, class_getter!(*names) class_getter!, class_getter?(*names, &block) class_getter?, class_property(*names, &block) class_property, class_property!(*names) class_property!, class_property?(*names, &block) class_property?, class_setter(*names) class_setter, def_clone def_clone, def_equals(*fields) def_equals, def_equals_and_hash(*fields) def_equals_and_hash, def_hash(*fields) def_hash, delegate(*methods, to object) delegate, forward_missing_to(delegate) forward_missing_to, getter(*names, &block) getter, getter!(*names) getter!, getter?(*names, &block) getter?, property(*names, &block) property, property!(*names) property!, property?(*names, &block) property?, setter(*names) setter

##
Constructor Detail

def self.new(output : IO, level : Int32 = Compress::Deflate::DEFAULT_COMPRESSION, strategy : Compress::Deflate::Strategy = Compress::Deflate::Strategy::DEFAULT, sync_close : Bool = false, dict : Bytes | Nil = nil) #

Creates an instance of Flate::Writer. `#close` must be invoked after all data has written.

##
Class Method Detail

def self.open(io : IO, level : Int32 = Compress::Deflate::DEFAULT_COMPRESSION, strategy : Compress::Deflate::Strategy = Compress::Deflate::Strategy::DEFAULT, sync_close : Bool = false, dict : Bytes | Nil = nil, &) #

Creates a new writer for the given io, yields it to the given block, and closes it at its end.

##
Instance Method Detail

def close : Nil #

Closes this writer. Must be invoked after all data has been written.

def closed? : Bool #

Returns `true` if this IO is closed.

def flush : Nil #

See `IO#flush`.

def inspect(io : IO) : Nil #
Description copied from class Reference

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

    class Person
      def initialize(@name : String, @age : Int32)
      end
    end

    Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

def read(slice : Bytes) : NoReturn #

Always raises `IO::Error` because this is a write-only `IO`.

def sync_close=(sync_close : Bool) #

If `#sync_close?` is `true`, closing this IO will close the underlying IO.

def sync_close? : Bool #

If `#sync_close?` is `true`, closing this IO will close the underlying IO.

def write(slice : Bytes) : Nil #

See `IO#write`.