Objective-CUm pouco de arqueologia

Tales Pinheiro@talesp, tales@newtlabs.com

Mestre em computação pelo IME/USP

Head of Technologies na Newt Labs

Dev iOS na Shopcliq (http://shopcliq.com.br)

Incentivador da @selfsp NSCoder Night

http://meetup.com/NSCoder-Night-self-SP/

[self SP]; //http://groups.google.com/forum/#!forum/selfsp

Tales Pinheiro de Andrade

Charles Babbage

Augusta Ada King

Fortran

Analyticlal Engine Order Code

CPC Building Scheme

Boehm Unnamed Coding system

Sequentielle Formelübersetzung

Speedcoding

Laning and Zieler

IT

Algol

Simula

CPL BCPL B C

Smalltalk

40s - Primeiras linguagens

Fortran

Analyticlal Engine Order Code

CPC Building Scheme

Boehm Unnamed Coding system

Sequentielle Formelübersetzung

Speedcoding

Laning and Zieler

IT

Algol

Simula

CPL BCPL B C

Smalltalk

Primeiras linguagens “Modernas”

Fortran

Analyticlal Engine Order Code

CPC Building Scheme

Boehm Unnamed Coding system

Sequentielle Formelübersetzung

Speedcoding

Laning and Zieler

IT

Algol

Simula

CPL BCPL B C

Smalltalk

Paradigmas fundamentais

Smalltalk

One day, in a typical PARC hallway bullsession, Ted Kaehler, Dan Ingalls, and I were standing around talking

about programming languages. The subject of power came up and the two of them wondered how large a language one

would have to make to get great power. With as much panache as I could muster, I asserted that you could define the “most powerful language in the world” in “a page of

code.” They said, “Put up or shut up.”

http://gagne.homedns.org/~tgagne/contrib/EarlyHistoryST.html

Origem

1981: Apresentação de Smalltalk na ITT Research Laboratory

Artigo sobre Smalltalk-80 na Byte Magazine

Se mudam para Schlumberger Research Labs

Tom Love adquire licença do Smalltalk-80

Se torna o primeiro cliente comercial

Cox e Love aprendem Smalltalk com a revista, código fonte e suporte

I could built a Smalltalk pre-processor for C in a couple of weeks: it’s just what we need

OOPC

1981 - Object Oriented Pre-Processor

ITT Research Laboratory, junto com Tom Love

sed, awk, compilador C...

1982 - Cox e Love deixam a Schlumberger Research Labs

Fundam a Productivity Products International (PPI)

Renomeada para StepStone (após investimento de VC)

Objective -C - Primeira versão

1982 - Desenvolvimento do pre-compilador

lex/yacc

1983 - Inicio da comercialização do Objective-C

Adiciona algumas bibliotecas de classes

1986 - Lançado Object Oriented Programming - An evolutionary approach

About that time Bjarne [Stroustrup] heard about our work and invited me to speak at Bell Labs, which was when I learned he was working on C++. Entirely different notions of what object-oriented meant. He wanted a better C (silicon fab line). I wanted a better way of soldering together components originally fabricated in C to build larger-scale assemblies.

http://moourl.com/89918

‘Concorrência” com C++

Primeira aparição da Apple

Apple é uma da primeiras interessadas no Objective-C

Além de Clascal, Object Pascal, Dylan*

“They did like PPI/Stepstone because we did such a good job finding errors in their C compiler!"

https://www.youtube.com/watch?v=mdhl0iiv478

NeXT

1985 - Jobs deixa a Apple e funda a NeXT

NeXT “vai as compras” de tecnologia

1988 - NeXT licencia uso de Objective-C da Stepstone

NeXTStep (OS) e o OpenStep (APIs)

Application Kit e Foundation Kit

Protocolos (conceito, mas não implementação, de herança multipla)

Objective-C open source

1988 - NeXT adiciona suporte ao GCC

Mas não liberam AppKit e Foundation

1992 - GNUStep: primeira implementação GPL incluindo runtime e libs

1993 - GNU Objective-C runtime

NeXT adquire Objective-C

1995 - NeXT adquire marcas e direitos do Objective-C

Vende de volta licença de uso para Stepstone

http://moourl.com/89918

Apple adquire NeXT

1996 - Apple adquire NeXT

Usa NeXTStep como base para criar o Mac OS X

Usa a especificação do OpenStep para criar a Cocoa

Anos depois, transforma Project Builder no Xcode

Objective-C 2.0

Anunciado na WWDC 2006

Garbage Collector (apenas no Mac OS X)

Melhorias de sintaxe

Melhorias no runtime

Suporte 64 bits

Disponibilizado no Mac OS X 10.5 (Leopard) em 2007

Objective-C 2.0

Melhorias na sintaxe

@property e @synthesize (ou @dynamic)

Protocolos com @optional e @required

Dot Syntax

Fast enumeration

Extensões de classe

@property e @synthesize - Antes@interface Person : NSObject { // instance variables NSString *_name;}- (NSString*)name;- (void)setName:(NSString*)aName;@end

@implementation Person- (NSString*)name { return _name;}- (void)setName:(NSString *)aName { if (aName != _name) { [_name release]; } _name = [aName retain];}@end

@property e @synthesize - Depois@interface Person : NSObject@property (retain) NSString *name;

@end

@implementation Person@synthesize name;

@end

Atributos para @property

Variáveis de instância publicas (@private e @protected)

Acesso: readonly (gera apenas o getter)

Semantica de armazenamento: assign, copy e retain

Thread safe: nonatomic

Permite nomear o getter

Atributos e getter nomeado@interface Person : NSObject {@private int age;@protected BOOL active;}@property (retain) NSString *name;@property (assign) int age;@property (assign, getter = isActive) BOOL active;@end

@implementation Person@synthesize name = _name;- (void)doSomething { Person *aPerson = [[Person alloc] init]; if ([aPerson isActive]) { [aPerson setActive:NO]; }}@end

@property e @synthesize

Key Value Coding:

NSString *name = [person valueForKey:@"name"];

[person setValue:@"Tales" forKey:@"name"];

Dot notation

Inicialmente, envio de mensagem era feito através de @property (retain) NSString *name;

[person name];

[person setName:@”Tales”];

Com Dot notation, é possível usarNSString *name = person.name;

person.name = @"John";

Ainda é enviada mensagem

Dot notation

Permite “aberrações”NSMutableArray *mutableArray = NSArray.alloc.init.mutableCopy;

Envio de mensagem pode causar problemas de performance

Sobre-uso (@property vs métodos) Person *p = [[Person alloc] init]; NSArray *thePeople = [NSArray arrayWithObject:p]; NSInteger numberOfPersons = thePeople.count;

Fast enumaration - Antes

Usando NSEnumerator@interface Person : NSObject@property (retain) NSString *name;@property (assign) int age;@end

@implementation Person- (void)doSomething { NSArray *thePeople = [NSArray array]; // Using NSEnumerator NSEnumerator *enumerator = [thePeople objectEnumerator]; Person *p; while ((p = [enumerator nextObject]) != nil) { NSLog(@"%@ is %i years old.", [p name], [p age]); }}@end

Fast enumaration - Antes

Usando indices@interface Person : NSObject@property (retain) NSString *name;@property (assign) int age;@end

@implementation Person- (void)doSomething { NSArray *thePeople = [NSArray array]; // Using indexes for (int i = 0; i < [thePeople count]; i++) { Person *p = [thePeople objectAtIndex:i]; NSLog(@"%@ is %i years old.", [p name], [p age]); }}@end

Fast enumaration - Depois

@interface Person : NSObject@property (retain) NSString *name;@property (assign) int age;@end

@implementation Person- (void)doSomething { NSArray *thePeople = [NSArray array]; // Using fast enumeration for (Person *p in thePeople) { NSLog(@"%@ is %i years old.", [p name], [p age]); }}@end

Modern Objective-C

Xcode 4 - Apple troca GCC por LLVM

Automatic Reference Counting

Blocks

Literais

@property com @synthesize padrão

NSDictionary e NSArray subscripting

iVar no bloco @implementation

Blocks

Adição ao C (e por extensão, ao Objective-C e ao C++) ainda não padronizada

Sintaxe inspirada em expressões lambda para criação de closures

OS X 10.6+ e iOS 4.0+

Bibliotecas de terceiros permitem OS X 10.5 e iOS 2.2+

Foco no uso com GCD

http://blog.bignerdranch.com/3001-cocoa-got-blocks/http://vimeo.com/68340179

Literais - antes

NSNumber *number = [NSNumber numberWithInt:0];NSArray *array = [NSArray arrayWithObjects:@"nome", @"sobrenome", nil];NSDictionary *dict = [NSDictionary dictionaryWithObjects:@"Tales", @"Pinheiro" forKeys:@"nome", @"sobrenome"];

Literais - depois

NSNumber *number = @0;NSArray *array = @[@"nome", @"sobrenome"];NSDictionary *dict = @{@"nome": @"Tales", @"sobrenome": @"Pinheiro"};

Default @synthesize

Não é mais necessário o @synthesize para uma @property

Compilador/runtime declaram automagicamente, equivalente a

@synthesize name = _name;

Subscripting

LLVM 4.0 ou posterior

Transforma id object1 = [someArray objectAtIndex:0]; id object2 = [someDictionary objectForKey:@"key"]; [someMutableArray replaceObjectAtIndex:0 withObject:object3]; [someMutableDictionary setObject:object4 forKey:@"key"];}

Em id object1 = someArray[0]; id object2 = someDictionary[@"key"]; someMutableArray[0] = object3; someMutableDictionary[@"key"] = object4;

Subscripting

Custom classes também permitem

Indexada:- (id)objectAtIndexedSubscript:(NSUInteger)idx;

- (void)setObject:(id)obj atIndexedSubscript:(NSUInteger)idx;

Por chave:- (id)objectForKeyedSubscript:(id <NSCopying>)key;

- (void)setObject:(id)obj forKeyedSubscript:(id <NSCopying>)key;

Subscripting

É poder (http://nshipster.com/object-subscripting/)

Permite criação de DSLroutes[@"GET /users/:id"] = ^(NSNumber *userID){

// ... }

id piece = chessBoard[@"E1"]; NSArray *results = managedObjectContext[@"Product WHERE stock > 20"];

“Com grandes poderes vêm grandes responsabilidades” BEN, Tio

O futuro

Módulos! Yay \o/

http://llvm.org/devmtg/2012-11/Gregor-Modules.pdf

http://clang.llvm.org/docs/Modules.html

Já disponível no Clang 3.4 (C e C++)

Headers são frageis e adicionam peso ao compilador

A fragilidade dos Headers

#define FILE "MyFile.txt"#include <stdio.h>int main() { printf(“Hello, world!\n”);}

A fragilidade dos Headers

#define FILE "MyFile.txt"// stdio.htypedef struct { //...} FILE;// on and on...

int main() { printf(“Hello, world!\n”);}

A fragilidade dos Headers

#define FILE "MyFile.txt"// from stdio.htypedef struct { //...} “MyFile.txt”;// on and on...

int main() { printf(“Hello, world!\n”);}

Tamanho dos headers

#include <stdio.h>int main() { printf(“Hello, world!\n”);}

#include <iostream>int main() { std::cout << “Hello, world!”}

C C++

Fonte

Headers

64 81

11.072 1.161.003

Módulos

import std; //#include <stdio.h>int main() { printf(“Hello, World!\n”);}

import permite adicionar um módulo nomeadoIgnora macros de pre-processador

Módulos

import std.stdio;int main() { printf(“Hello, World!\n”);}

import permite modo seletivo

Módulos

Vejam sessão 404 da WWDC 2013

Obrigado :D