1. Programming Language Paradigms ITSK2314 Lecture 3

2. Agenda  What is a programming language  Abstractions  History  Computational Paradigms

3. Programming Language Defined  Notation system Symbols/grammar  Describe computation Anything a computer can do (Turing)  Machine-readable Unambiguous, finite algorithm  Human-readable Abstraction mechanisms needed

4. Design Issues  Efficiency  Writability  Readability  Expressiveness  Orthogonality  Simplicity  Extensibility  Machine Independence  Security

5. Abstractions  Data abstractions Variables Structures  Unit abstractions Abstract Data Types (classes) Packages Procedures, functions, methods  Control abstractions Assignment Goto If-then, case/switch loops

6. History  1830s/1840s Charles Babbage (Analytical Engine) Ada Lovelace  First programmer Sequence of cards w/ data & operations  1950s First programming languages  COBOL, LISP, Algol First high-level language – FORTRAN  1960s Special-purpose languages (> 100)  1970s Simplicity, structure, efficient Pascal, C  1980s Object-oriented languages  1990s Libraries, scripting, distributed/network computing

7. Computational Paradigms  Imperative/Procedural C, Pascal  Functional (applicative) LISP, Scheme  Logic Prolog  Object-oriented C++, Java, C#, Smalltalk  Parallel C, FORTRAN  Distributed

8. FIN