History of the language self

• Sandeep K Gude

History

•Designed by - David Ungar, Randall Smith

•Presented as "SELF: The Power of Simplicity", OOPLSA '87,

History Continued…..

•Initial implementation was undertaken at Stanford University in 1987

•Self was used as a vehicle for language, environment, user interface and implementation research

History continued….

•A public releases of Self from stanford took place in 1990.

•In 1991 the Self project moved to Sun Microsystems Labs.

Context

•There is a (n)ever ending thirst for a pure object oriented approach of programming.

•eg Camp Smalltalk: meetings for discussions on Object oriented programming

Context ….

• A programming language which can be self supporting

•A programming langugage which can over come the inadequacies of the operating system.

Elements of the language

• Elements of the language

• Kristin Ruble

What is Different about SELF

• No Classes• No variables• Objects have slots not

instance variables• Objects created by

“cloning” a prototype

Self based on a small number of simple

and concrete ideas

• Prototypes• Slots • Behavior

Prototypes

• Prototypes combine inheritance and instantiation to provide a framework that is simpler and more flexible than most object-oriented languages

Slots

• Slots unite variables and procedures into a single construct

• This permits the inheritance hierarchy to take over the function of lexical scoping in conventional languages

Behavior

• Self does not distinguish state from behavior

• Narrows the gaps between ordinary objects, procedures, and closures

• Self's simplicity and expressiveness offer new insights into object-oriented computation.

SELF Objects

Self Objects

Example:SELF True

Its position with respect to other languages

• Brian Barcomb

Similarities

• Object-Oriented

Similarities

• Object-Oriented

• Closely related to Smalltalk

-syntax

-no type declarations

-block usage

-exploratory style

Differences

• Simplicity

• Concreteness

• No Classes

• Object-Level Inheritance

• Prototypes

• Messages

In a class-based language

In SELF

Conclusion of Language Comparison

Self’s simplicity and expressiveness offer new insights into object oriented computation