Reference
class Reference
Overview
Reference
is the base class of classes you define in your program- It is set as a class' superclass when you don't specify one:
class MyClass # < Reference end
A reference type is passed by reference: when you pass it to methods, return it from methods or assign it to variables, a pointer is actually passed.
Invoking .new
on a Reference
allocates a new instance on the heap- The instance's memory is automatically freed (garbage-collected) when the instance is no longer referred by any other entity in the program-
Direct Known Subclasses
- Array(T)
- Benchmark::BM::Job
- Benchmark::BM::Tms
- Benchmark::IPS::Entry
- Benchmark::IPS::Job
- Box(T)
- Channel(T)
- Crypto::Bcrypt
- Crypto::Bcrypt::Password
- Crypto::Blowfish
- Crystal::Macros::ASTNode
- CSV
- CSV::Builder
- CSV::Lexer
- CSV::Parser
- Deque(T)
- Digest::Base
- Dir
- Event::SignalChildHandler
- Event::SignalHandler
- Exception
- Fiber
- Flate::Reader
- Flate::Writer
- Gzip::Header
- Gzip::Reader
- Gzip::Writer
- Hash(K, V)
- HTTP::Client
- HTTP::Client::Response
- HTTP::CompressHandler
- HTTP::Cookie
- HTTP::Cookies
- HTTP::ErrorHandler
- HTTP::FormData::Builder
- HTTP::FormData::Parser
- HTTP::LogHandler
- HTTP::Multipart::Builder
- HTTP::Multipart::Parser
- HTTP::Params::Builder
- HTTP::Request
- HTTP::Server
- HTTP::Server::Context
- HTTP::Server::RequestProcessor
- HTTP::Server::Response
- HTTP::StaticFileHandler
- HTTP::WebSocket
- HTTP::WebSocket::Protocol::StreamIO
- HTTP::WebSocketHandler
- INI
- IO::Delimited
- IO::FileDescriptor
- IO::Hexdump
- IO::Memory
- IO::MultiWriter
- IO::Sized
- Iterator::Stop
- JSON::Builder
- JSON::Lexer
- JSON::Parser
- JSON::PullParser
- JSON::Token
- Levenshtein::Finder
- LLVM::ABI
- LLVM::ABI::FunctionType
- LLVM::Builder
- LLVM::Context
- LLVM::FunctionPassManager
- LLVM::GenericValue
- LLVM::JITCompiler
- LLVM::MemoryBuffer
- LLVM::Module
- LLVM::ModulePassManager
- LLVM::PassManagerBuilder
- LLVM::TargetMachine
- Logger
- Markdown
- Markdown::HTMLRenderer
- Markdown::Parser
- Mutex
- OAuth2::AccessToken
- OAuth2::Client
- OAuth2::Session
- OAuth::AccessToken
- OAuth::Consumer
- OAuth::RequestToken
- OpenSSL::Digest
- OpenSSL::HMAC
- OpenSSL::MD5
- OpenSSL::SHA1
- OpenSSL::SSL::Context
- OpenSSL::SSL::Socket
- OptionParser
- PrettyPrint
- Process
- Process::Status
- Random::MT19937
- Regex
- Regex::MatchData
- Spec::VerboseFormatter::Item
- String
- String::Builder
- StringPool
- StringScanner
- URI
- WeakRef(T)
- YAML::Builder
- YAML::Parser
- YAML::PullParser
- Zip::File
- Zip::File::Entry
- Zip::Reader
- Zip::Reader::Entry
- Zip::Writer
- Zip::Writer::Entry
- Zlib::Reader
- Zlib::Writer
Defined in:
primitives.crreference.cr
Class Method Summary
Instance Method Summary
- #==(other : self)
Returns
true
if this reference is the same as other. - #==(other)
Returns
false
(other can only be aValue
here)- - #dup
Returns a shallow copy of this object.
- #hash
Returns this reference's
#object_id
as the hash value. - #inspect(io : IO) : Nil
- #object_id : UInt64
Returns a
UInt64
that uniquely identifies this object. - #pretty_print(pp) : Nil
- #same?(other : Reference)
Returns
true
if this reference is the same as other. - #same?(other : Nil)
Returns
false
: a reference is nevernil
. - #to_s(io : IO) : Nil
Instance methods inherited from class Object
!=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)===(other : YAML::Any)
===(other) ===, =~(other) =~, class class, dup dup, hash hash, inspect(io : IO)
inspect inspect, itself itself, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, tap(&block) tap, to_json(io : IO)
to_json to_json, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ") to_pretty_json, to_s
to_s(io : IO) to_s, to_yaml(io : IO)
to_yaml to_yaml, try(&block) try
Class methods inherited from class Object
from_json(string_or_io, root : String) : selffrom_json(string_or_io) : self from_json, from_yaml(string_or_io) : self from_yaml
Class Method Detail
def self.newSource
Instance Method Detail
def dupSource
Returns a shallow copy of this object.
This allocates a new object and copies the contents of self
into it.
def hashSource
Returns this reference's #object_id
as the hash value.
def object_id : UInt64Source
Returns a UInt64
that uniquely identifies this object.
The returned value is the memory address of this object.
string = "hello" string.object_id # => 4460249568 pointer = Pointer(String).new(string.object_id) string2 = pointer.as(String) string2.object_id == string.object_id # => true
def same?(other : Reference)Source
Returns true
if this reference is the same as other. This is only true
if this reference's #object_id
is the same as other's.
© 2012–2017 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.22.0/Reference.html