This document summarizes a workshop on programming paradigms. It defines programming paradigms as fundamental styles of computer programming that serve as patterns or models for programming languages. The workshop covers various programming concepts like eager vs lazy evaluation, procedures vs functions, external vs internal state, concurrency, and static vs dynamic typing. It also uses examples like searching and higher order functions to illustrate differences between paradigms like Java vs Prolog and Java vs Haskell.

1. Programming Paradigms ( http://www.directi.com | http://wiki.directi.com | http://careers.directi.com )‏ Licensed under Creative Commons Attribution Sharealike Noncommercial By, Janeve George [email_address] & Nilesh Mevada [email_address]

8. Creative Commons Sharealike Attributions Noncommercial Why bother about 'Programming Paradigms'?

9. Creative Commons Sharealike Attributions Noncommercial Why bother about 'Programming Paradigms'?

10. Creative Commons Sharealike Attributions Noncommercial Why bother about 'Programming Paradigms'?

15. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – An Overview Set of Programming Concepts Procedures Functions Higher/1 st Order Evaluation Eager/Lazy Variables Single/Multi store Scope Scope of variables Typing State Internal/External Objects Classes Concurrency & on & on & on.....

16. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – An Overview Subset of Concepts Programming Model Set of Programming Concepts Programming Language(s)‏ Embraced by Followed by Embraced by Followed by

19. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – An Overview

20. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – An Overview

23. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Eager Evaluation .... List Gen ( int N ) { ArrayList list = new ArrayList(); list. add ( N ); list. addAll ( Gen (N+1) ); return list; } void myMethod () { List K = Gen (1); System.out. println ( "Elements: " + K. getElementAt ( 3 ) ); } ....

25. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Lazy Evaluation declare fun lazy { Gen N} N | { Gen N+1} end declare K = { Gen 1} { Browse “Elements: ” + Nth K 3}

27. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Procedures local Default MaxOrDefault in Default=10 proc { MaxOrDefault Arg ?Result} if Arg >= Default then Result = Arg else Result = Default end end local Result in { MaxOrDefault 5 Result} { Browse Result} end end

30. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Functions (Higher Order)‏ listsum [] = 0 listsum (x:xs) = x + listsum xs listprod [] = 1 listprod (x:xs) = x * listprod xs fold op init [] = init fold op init (x:xs) = x `op` fold op init xs listsum = fold (+) 0 listprod = fold (*) 1

32. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – External and Internal State fun { Sum Numbers} Result = { NewCell 0} Input = { NewCell Numbers} proc { Sum } case @Input of nil then skip [] X | Y then Result := @Result + X Input := Y { Sum } end end in { Sum } @Result end

34. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Concurrency fun { GenerateNumbers FromArg ToArg} { Delay 100} if FromArg > ToArg then nil else FromArg | { GenerateNumbers FromArg+1 ToArg} end end thread ConcurrentFlow1 = { GenerateNumbers 1 10} end thread ConcurrentFlow2 = { GenerateNumbers 11 20} end { Browse ConcurrentFlow1} { Browse ConcurrentFlow2}

35. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Concurrency .... public void main(String[] args) throws InterruptedException { Temp temp = new Temp(); createAConcurrentFlow(1, 10); createAConcurrentFlow(11, 20); } .... private void createAConcurrentFlow( int FromArg, int ToArg) { new Runnable() { public void run() { try { new Temp().GenerateNumbers(FromArg, ToArg); } catch (InterruptedException e) { } } }; } ....

37. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Static Typing int num, sum; // explicit declaration num = 5; // now use the variables sum = 10; sum = sum + num;

39. Creative Commons Sharealike Attributions Noncommercial Programming Concepts – Dynamic Typing foo() { x = 1; x = 'hello'; }

41. Creative Commons Sharealike Attributions Noncommercial Some Real-Life Problems – Prolog vs Java % % Facts % male(hrithik). male(shahrukh). male(salman). male(abhishek). male(akshay). male(aamir). female(diya). female(aishwarya). female(katrina). female(malaika). parent(hrithik,shahrukh). parent(hrithik,salman). parent(hrithik,diya). parent(shahrukh,abhishek). parent(shahrukh,akshay). parent(salman,aishwarya). parent(salman,katrina). parent(salman,aamir). parent(diya,malaika). % % Rules % father(X,Y) :- parent(X,Y), male(X). mother(X,Y) :- parent(X,Y), female(X). grandparent(X,Y) :- parent(X,Z), parent(Z,Y). paternalgrandfather(X,Y) :- father(X,Z), father(Z,Y). sibling(X,Y) :- parent(Z,X), parent(Z,Y). brothers(X,Y) :- sibling(X,Y),male(X),male(Y), (X=Y). % % Queries % cmd: mother(diya,malaika) % Outupt: yes/no cmd: mother(Mother,Child). % Output: lists (mother,child) pair found in facts % according to associations defined

42. Creative Commons Sharealike Attributions Noncommercial Some Real-Life Problems – Statistics

46. Questions??? [email_address] & [email_address] http://directi.com http://careers.directi.com Download slides: http://wiki.directi.com

47. Retrospective!!! [email_address] & [email_address] http://directi.com http://careers.directi.com Download slides: http://wiki.directi.com