Data-Oriented programming
The secret ๐ sauce ๐ that makes Clojure systems less complex
Yehonathan Sharvit viebel
๐Who am I?
๐ป Developer since 2001 (Clojure since 2012)
๐๏ธMaintainer of Klipse
๐ Author of Data-Oriented programming
๐ Blogger at blog.klipse.tech
๐ Definitions
๐ Secret sauce
An element, quality, ability, or practice that makes something or someone successful or distinctive.
Merriam-Webster dictionary
๐ฐComplexity
What makes large systems hard to understand.
Out of the Tar Pit (2006)
๐ค What makes Clojure distinctive?
โ A brief history of Data-Oriented programming
1936 ๐ ฮป-calculus (Alonzo Church)
1958 ๐ LISP (John McCarthy)
1981 ๐ Values and Objects in Programming Languages (Bruce MacLennan)
2000 ๐ Ideal Hash trees (Phil Bagwell)
2006 ๐ Out of the Tar Pit (Ben Moseley and Peter Marks)
2007 ๐ Clojure (Rich Hickey)
2021? ๐ Wikipedia article about Data-Oriented programming (Help wanted)
๐The main ideas of LISP
Data-Oriented Computing with symbolic expressions | Functional Programming Composition of functions |
Homoiconicity Representation of LISP programs as LISP data | The REPL? The function |
History of Lisp, John McCarthy 1979
๐ก Principles of Data-Oriented programming
Data is a first-class citizen โ๏ธ
Separate code from data
Represent data with generic data structures
Do not mutate data
Language agnostic
OO and FP
Statically or dynamically typed
Applicable in isolation
Powerful when combined
๐Design a library management system
๐ธ๏ธWhat makes this system complex?
Nodes with many edges
Many kind of arrows
Association
Composition
Inheritance
Usage
๐ก Principle #1: Separate Code from Data
Breaking the principle in FP ๐
function createAuthor(firstName,
lastName) {
return {
fullName: function() {
return firstName + " " + lastName;
}
};
}Adhering to the principle in OOP ๐
class AuthorData {
constructor(firstName, lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
}class NameCalculation {
static fullName(data) {
return data.firstName + " "
+ data.lastName;
}
}๐ Reduction of System Complexity
โWhat makes this system less complex?
Separation of concerns
Code diagram constraints
Stateless (static)
Only usage relation
Data diagram constraints
Only association and composition
๐กPrinciple #2: Represent Data with generic data structures
Breaking the principle ๐
class Book {
isbn; title;
constructor(publicationYear, title) {
this.publicationYear = publicationYear;
this.title = title;
}
}
var watchmenBook = new Book("978-1779501127",
"Watchmen");Adhering to the principle ๐
var watchmenBook = new Map([
["publicationYear", 1986],
["title", "Watchmen"]
]);๐ Reduction of System Complexity even more
๐ ๐ ๐
๐ ๐ ๐
โWhat makes this system less complex?
Weak dependency between code and data
Loose coupling between components
Flexible data model
Generic data manipulation functions
๐ Visualize the system data
Information path (e.g.
["catalog", "authorsById", "alan-moore", "name"])Display data on console
Serialization for free
Reflection for free
๐ก Principle #3: Do not mutate Data
Mutation is bad!
๐จโ๐ปApplication of DO principles
โณSummary
Separate Code from Data
Represent Data with generic data structures
Do not mutate data
๐นImagine
๐คCollaborate