Embed Size (px)
DESCRIPTION
Keynote talk given at JDay Lviv 2014 in Ukraine (http://www.jday.com.ua/). Video coming soon. Abstract: Some say that there's nothing new under the sun. However, looking back on five to six decades of computing, it's easy to see that things progress at their own leisurly pace. Structured programming, originating in the '60s, did not gain mainstream adoption until the '80s; object-oriented programming was hotly debated in the '70s and '80s but only gained widespread acceptance in the '90s. Every couple of decades sees an engineering leap that radically improves the software engineering discipline across the board. I believe we are now at such an inflection point, with functional programming concepts slowly sifting into the mainstream. After this talk, I hope you will too.
Citation preview
Functional Leap of Faith
Tomer Gabel, WixJDay Lviv 2014
Through the Looking Glass
20 years ago…
• C/C++ rule the
market [1]
• First release of
Java
[1] TIOBE Index (historical data)
… since then?*
• C and Java are neck-and-neck• Virtual machines are everywhere• Garbage collection is everywhere• OOP is everywhere
* Not exhaustive
Virtual Machines
1967 BCPL
1978 UCSD p-System
1994 JVM
2014 Everywhere!
Garbage Collection
1960 Formalized[1]
1970s Research
1994 JVM
2014 Everywhere!
[1] Recursive Functions of Symbolic Expressions and Their Computation by Machine, Part I
Object-Oriented Programming
1967 Simula 67
1980 Smalltalk 80
1983 C++
2014 Everywhere!
Advances take decades to become mainstream
Market Growth[1]
1975 1980 1985 1990 1995 2000 2005 2010 2015* 2020*0
500000000
1000000000
1500000000
2000000000
2500000000
3000000000
[1] eTForecasts Worldwide PC Market Research Report
1975 1980 1985 1990 1995 2000 2005 2010 2015* 2020*0
500000000
1000000000
1500000000
2000000000
2500000000
3000000000
Market Growth
• Structured Programming
• Module Systems
• Dynamic Memory
Allocation
1975 1980 1985 1990 1995 2000 2005 2010 2015* 2020*0
500000000
1000000000
1500000000
2000000000
2500000000
3000000000
Market Growth
• Garbage Collection
• OOP
• VMs and JIT
1975 1980 1985 1990 1995 2000 2005 2010 2015* 2020*0
500000000
1000000000
1500000000
2000000000
2500000000
3000000000
Market Growth
You are here!
What’s holding us back?
The Market has Shifted
• SaaS is the norm
• Shorter time to market
• Latency requirements are stricter
• Availability is business-critical
The Free Lunch is Over[1]
[1] The Free Lunch is Over, Herb Stutter (Dr. Dobb's Journal, 2005)
• CPUs aren’t getting (much) faster
• Rather, they’re getting parallel
• Concurrency is the new kid on the block
Datasets are Getting Bigger
• Terabyte-scale data is common
• Computation demand – NoSQL– Big Data
• Specialized hardware (SAN) is a hindrance
We need new abstractions.
Three desirable attributes:
Today’s systems
are highly available & reliable.
Tomorrow’s abstraction must…
encourage correct code.
Complexity is the Mind Killer
• Complex system bigger
codebase
• More code more bugs
• We want less code
• We want correct code
Control flow Data flow
We need to invert our thinking.
How What
We need to invert our thinking.
Control flow describes the how
List<Person> adults(List<Person> in) {
ArrayList<Person> out = new ArrayList<>();
for (Person p : in) if (p.getAge() >= 18) out.add(p);
return out;}
Data flow describes the what
List<Person> adults(List<Person> in) { return in.stream() .filter(p -> p.age >= 18) .collect(Collectors.toList());}
“What” is Better
• Focuses on the problem
• Reduces accidental complexity
• Decouples intent from execution
I WANT YOU
TO STOPWORRYING
ABOUT TRIVIA
Today’s systems
are highly concurrent.
Tomorrow’s abstraction must…
encourage immutability.
The Case for Immutability
• Inherently thread-safe
• Referentially transparent
• Easier to reason about!
Today’s systems
are horizontally scalable.
Tomorrow’s abstraction must…
simplify workload distribution.
Distribution 101
1. Take a core computation
2. Split it out
3. Run on many nodes
4. Profit
Why is this hard?
• Behavior-as-data
• Side effects
• High-performance
frameworks
Lambdas
Immutability
Akka, Hadoop,
Storm…
The future is functional.
1. Data flow-oriented
2. Immutable3. Easy to
distribute
THANK YOU FOR YOUR TIME!
@tomerg
http://il.linkedin.com/in/tomergabel
