OOP Class Lawrence D’Antonio Lecture 2 History of OOP and C++

OOPL  Simula  Smalltalk  C++  Java  Python  C#  Eiffel  Ruby

More OOPL  Dylan  Modula 3  Self  Sather  Forté  Objective C  Object Pascal  Visual Basic  Perl

More OOPL  PHP  REBOL  CLOS  Delphi  COBOL  Prolog  Ada DDDD

History of Simula  Developed by Kristen Nygaard and Ole- Johan Dahl.  Carried out at the Norwegian Computing Center.  Designed as a system description language, built on ALGOL 60, to implement simulations.  Development was begun in 1961, leading to the definition of Simula 1 in

History of Simula – Part 2   Process concept: Active customers moving through a passive network. System = Set of interacting processes   In 1965, Tony Hoare introduced the concept of a record class for handling records.   Nygaard and Dahl introduce the concept of processes with layers in Simula 67.

Simula 67 features   Introduced classes, subclasses, virtual methods   Garbage collection

Simula example Class Rectangle (Width, Height); Real Width, Height; ! Class with two parameters; Begin Real Area, Perimeter; ! Attributes; Procedure Update; ! Methods (Can be Virtual); Begin Area := Width * Height; Perimeter := 2*(Width + Height) End of Update; Boolean Procedure IsSquare; IsSquare := Width=Height; Update; ! Life of rectangle started at creation; OutText("Rectangle created: "); OutFix(Width,2,6); OutFix(Height,2,6); OutImage End of Rectangle; End of Rectangle

History of Smalltalk  Developed at Xerox PARC in  Developed by Alan Kay et al to be a compact powerful OOPL, analogous to LISP. Alan KayAlan Kay  Designed in parallel to the Dynabook project.  Public release in 1980 (Smalltalk-80).

Smalltalk features  Pure object-oriented  Dynamically and strongly typed  Reflective language (self-modifying)  Garbage collection  Everything is an object. Classes are instances of metaclasses.

Smalltalk example | x y className methodName | className := 'Foo'. methodName := 'hello'. x := (Compiler evaluate: className). (x isKindOf: Class) ifTrue: [ y := x new. (y respondsTo: methodName asSymbol) ifTrue: [ y perform: methodName asSymbol ]

History of Ada  In 1975, DoD put out a request for a language meeting certain goals (Steelman requirements). No existing language met these goals, so a new language was created. Steelman  Jean Ichbiah created the language Ada – 83 to meet these goals.  Ada – 95 was the next installment of the language, designed by S. Tucker Taft.

Ada Features  Exception handling  Modularity  Statically and strongly typed.  Generics  Dynamic binding  Inheritance  Garbage collection

Ada Example with dates; use dates; -- definition of type date package persons is type person is tagged record name :string(1..10); dob :date; salary :float := 0.0; end record; procedure employ(someone:in out person); procedure dismiss(someone:in out person); procedure pay_raise(someone:in out person); end persons;

Ada Example, Part 2 with persons; use persons; package managers is type manager is new person with record master_key_code :string(1..10); end record; procedure allocate_master_key( someone:in out manager; code :in string); procedure pay_raise(someone:in out person); end managers;

Python History   Developed in late 1980’s by Guido van Rossum. Open source.   Published in   Version 1.0 released in   Versions 1.6 and 2.0 released in   GNU GPL compatible since 2001   Python 3.0 (Python 3000) released in alpha version in 2007.

Python Features   Simple, easy to learn language   Dynamically and strongly typed   Metaclasses   Exception handling   Garbage collection

Python Example class Stack: def __init__(self): # Initialize the stack self.stack = [ ] def push(self,object): self.stack.append(object) def pop(self): return self.stack.pop() def length(self): return len(self.stack) #Example s = Stack() # Create a stack s.push("Dave") # Push some things onto it s.push(42) s.push([3,4,5]) x = s.pop() # x gets [3,4,5] y = s.pop() # y gets 42 del s # Destroy s

C++ History   Bjarne Stroustrup began working on the idea of an efficient OOPL in 1979 at AT&T Labs.   Started developing C with Classes, that combined features of Simula and C.   1980 version had classes, inheritance, public/private, ctors and dtors, friends, type checking, inline, overloading assignment operator

C++ History – Part 2   Finished the first C++ compiler, Cfront, in Cfront was written in C++, but converted code into C.   In 1983, Rick Mascitti suggested the name C++ for the language.   Added features: virtual functions, overloading, references, const, operator new

C++ History – Part 3   In 1985, published first edition of The C++ Programming Language and version 1.0 of C++ released.   In 1989, version 2.0 released. Added features: multiple inheritance, abstract classes, const member functions, protected members.   In 1990, The Annotated C++ Reference Manual was published.

C++ History – Part 4   Templates proposed in   Exception handling designed, with Andrew Koenig, in   I/O library designed by Jerry Schwarz and Koenig for version 2.0.   X3J16 standardization committee formed in December 1989.

Standard Template Library History   In 1987 Alex Stepanov and David Musser, at GE R&D, developed a generic list processing library for Ada.   Stepanov presented his idea of a generic library for C++ at the November 1993 meeting of X3J16.   The library design was developed (with Meng Lee) and approved at the March 1994 meeting.

C++ History – Part 5   C++ standard was approved on November 14,   Corrected version of the standard was approved in 2003.

C++ - the Future   Library Technical Report 1 (TR1) released in Suggestions such as smart pointers, metaprogramming, improved functors, improved numerical functions, regular expressions, fixed size array class, hash tables. Expected to be adopted for next version of standard.