Programming paradigms

Question 1

Imperative

Answer 1

Control flow is an explicit sequence of commands

Question 2

Declarative

Answer 2

Programs state the result you want, not how to get it

Question 3

Structured

Answer 3

Programs have clean, goto-free, nested control structures

Question 4

Procedural

Answer 4

Imperative programming with procedure calls

Question 5

Functional (Applicative)

Answer 5

Computation proceeds by (nested) function calls that avoid any global state

Question 6

Function-Level (Combinator)

Answer 6

Programs have no variables. No kidding

Question 7

Object-Oriented

Answer 7

Computation is effected by sending messages to objects; objects have state and behavior

Question 8

Object-Oriented: Class-based

Answer 8

Objects get their state and behavior based on membership in a class

Question 9

Object-Oriented: Prototype-based

Answer 9

Objects get their behavior from a prototype object

Question 10

Event-Driven

Answer 10

Control flow is determined by asynchronous actions (from humans or sensors)

Question 11

Flow-Driven

Answer 11

Computation is specified by multiple processes communicating over predefined channels

Question 12

Logic (Rule-based)

Answer 12

Programmer specifies a set of facts and rules, and an engine infers the answers to questions

Question 13

Constraint

Answer 13

Programmer specifies a set of constraints, and an engine infers the answers to questions

Question 14

Aspect-Oriented

Answer 14

Programs have cross-cutting concerns applied transparently

Question 15

Reflective

Answer 15

Programs manipulate their own structures

Question 16

Array

Answer 16

Operators are extended to arrays, so loops are normally unnecessary

Question 17

Concurrent by default

Answer 17

For example, imagine you wrote three lines of code, A, B, and C:

A;
B;
C;
In most programming languages, A would execute first, then B, and then C. In a language like ANI, A, B, and C would all execute at the same time!

Question 18

Dependent types

Answer 18

You’re probably used to type systems in languages like C and Java, where the compiler can check that a variable is an integer, list, or string. But what if your compiler could check that a variable is “a positive integer”, “a list of length 2”, or “a string that is a palindrome”?

This is the idea behind languages that support dependent types: you can specify types that can check the value of your variables at compile time.

Question 19

Concatenative languages

Answer 19

The idea is that everything in the language is a function that pushes data onto a stack or pops data off the stack; programs are built up almost exclusively through functional composition (concatenation is composition).

This sounds pretty abstract, so let’s look at a simple example in cat:

2 3 +