You Should Try Elixir

Talk at YEGRB, December 2014

Transcript

1. You Should Try Elixir Nathan Feaver, Senior Developer @ AgileStyle
2. Example: FizzBuzz f i z z b u z z ( n ) = F i z z B u z z i f r e m ( n / 3 ) = 0 a n d r e m ( n / 5 ) = 0 F i z z i f r e m ( n / 3 ) = 0 B u z z i f r e m ( n / 5 ) = 0 n {
3. | Example: FizzBuzz d e f m o d u l e F i z z B u z z d o d e f f i z z _ w o r d ( 0 , 0 , _ ) , d o : " F i z z B u z z " d e f f i z z _ w o r d ( 0 , _ , _ ) , d o : " F i z z " d e f f i z z _ w o r d ( _ , 0 , _ ) , d o : " B u z z " d e f f i z z _ w o r d ( _ , _ , n ) , d o : n d e f f i z z b u z z ( n ) d o f i z z _ w o r d ( r e m ( n , 3 ) , r e m ( n , 5 ) , n ) e n d d e f p r i n t ( n ) d o 1 . . n | > E n u m . m a p ( f n ( n ) - > f i z z b u z z ( n ) e n d ) | > E n u m . j o i n ( " , " ) | > I O . p u t s e n d e n d F i z z B u z z . p r i n t ( 1 0 0 ) Pattern Matching Pipe Operator
4. Elixir has changed the way I think about programming. Not just in terms of "Oh, its a functional language", it's actually changed my conception of what it means to program. ~ Dave Thomas “
5. Why Should I Try Elixir?
6. Other People Are Doing It
7. Elixir has changed the way I think about programming. Not just in terms of "Oh, its a functional language", it's actually changed my conception of what it means to program. ~ Dave Thomas “ Taken from: Think Different
8. I want to long term use [Elixir and the Phoenix Framework] to replace all of my client work and everything I want to build personally ~ Chris McCord “ Taken from: Rise of The Phoenix - Building an Elixir Web Framework
9. Programming in Erlang sucks. Elixir is everything good about Erlang and none — almost none — of the bad. ~ Devin Torres “ Taken from: The Excitement of Elixir
10. José Valim
11. Why Should I Try Elixir?
12. It's Built on the Erlang Virtual Machine
13. Erlang Erlang was originally developed in 1986 by Ericsson for telephony applications to support highly concurrent systems Mature Language/Tools/Community Concurrency (OTP) Distributed (OTP) Fault Tolerant Hot code swapping
14. Erlang libraries are simple to use! Elixir doesn't have built-in random or time libraries (although there are multiple packages). Let's use Erlang's libraries: d e f m o d u l e R a n d o m d o d e f u n i f o r m d o : r a n d o m . u n i f o r m e n d d e f s e e d d o : r a n d o m . s e e d ( : e r l a n g . n o w ) e n d e n d
15. Why Should I Try Elixir?
16. It's Easy to Get Started Ruby-like Syntax Programming Elixir – Dave Thomas elixir-lang.org/getting_started/1.html Exercism.io
17. Great Toolset for a Young Language b r e w i n s t a l l e l i x i r Rake ~> Mix Bundler ~> Hex IRb ~> IEx RSpec ~> ExUnit
18. Why Should I Try Elixir?
19. Curiosity About Functional Languages
20. Curiosity About Concurrency Concurrency
21. Metaprogramming d e f m a c r o m a t c h ? ( l e f t , r i g h t ) d o q u o t e d o c a s e u n q u o t e ( r i g h t ) d o u n q u o t e ( l e f t ) - > t r u e _ - > f a l s e e n d e n d e n d i e x > l i s t = [ { : a , 1 } , { : b , 2 } , { : a , 3 } ] [ a : 1 , b : 2 , a : 3 ] i e x > E n u m . f i l t e r l i s t , f n ( t h i n g ) - > m a t c h ? ( { : a , _ } , t h i n g ) e n d [ a : 1 , a : 3 ] Taken from: Elixir: It's Not About Syntax
22. The Phoenix Web Framework
23. Jobs! But not in Edmonton
24. Okay, I Want to Try Elixir! b r e w i n s t a l l e l i x i r Programming Elixir – Dave Thomas Distribution/Concurrency Tutorial: elixir-lang.org Exercism.io How I Start. Elixir With José Valim: Portal
25. THE END nathan@agilestyle.com Slides on GitHub: jfeaver/talk-try-elixir
26. Some More Elixir
27. Head | Tail Recursion d e f m o d u l e M a t h d o d e f s u m _ l i s t ( [ h e a d | t a i l ] , a c c u m u l a t o r ) d o s u m _ l i s t ( t a i l , h e a d + a c c u m u l a t o r ) e n d d e f s u m _ l i s t ( [ ] , a c c u m u l a t o r ) d o a c c u m u l a t o r e n d e n d M a t h . s u m _ l i s t ( [ 1 , 2 , 3 ] , 0 ) # = > 6 Taken from: Elixir Getting Started: Recursion
28. Immutability
29. Concurrency/Distribution (OTP) # C o m p i l e t h e m o d u l e a n d c r e a t e a p r o c e s s t h a t e v a l u a t e s ` a r e a _ l o o p ` i n t h e s h e l l p i d = s p a w n ( f n - > G e o m e t r y . a r e a _ l o o p ( ) e n d ) # = > # P I D < 0 . 4 0 . 0 > # S e n d a m e s s a g e t o ` p i d ` t h a t w i l l m a t c h a p a t t e r n i n t h e r e c e i v e s t a t e m e n t s e n d p i d , { : r e c t a n g l e , 2 , 3 } # = > A r e a = 6 # { : r e c t a n g l e , 2 , 3 } s e n d p i d , { : c i r c l e , 2 } # = > A r e a = 1 2 . 5 6 0 0 0 0 0 0 0 0 0 0 0 0 0 4 9 7 3 8 # { : c i r c l e , 2 } # T h e s h e l l i s a l s o a p r o c e s s , y o u c a n u s e ` s e l f ` t o g e t t h e c u r r e n t p i d s e l f ( ) # = > # P I D < 0 . 2 7 . 0 > Taken from: Learn X in Y Minutes - Elixir
30. Pattern Matching i e x > a = [ 1 , 2 , 3 ] i e x > b = [ [ 1 , 2 , 3 ] ] i e x > [ c ] = [ [ 1 , 2 , 3 ] ] i e x > a = = c t r u e i e x > [ x , y , z ] = [ 1 , 2 , 3 ] i e x > z 3 i e x > " T o d a y i s " < > d a t e = " T o d a y i s D e c e m b e r 1 6 t h " i e x > d a t e " D e c e m b e r 1 6 t h " d e f m o d u l e M y A p p d o d e f c a l l b a c k ( : o k , d a t a ) d o # s u c c e s s e n d d e f c a l l b a c k ( : e r r o r , d a t a ) d o # h a n d l e f a i l u r e e n d e n d Back To FizzBuzz
31. Pipe Operator The pipe operator(| > ) is most helpful when transforming data through a sequence. The operator pipes the result of an expression into the first argument of the next function. Confusing, nested function calls no longer need temporary variables to make them readable: # C o n f u s i n g , n e s t e d f u n c t i o n c a l l s d e f p r i n t ( n ) d o I O . p u t s ( E n u m . j o i n ( E n u m . m a p ( 1 . . n , f n ( n ) - > f i z z b u z z ( n ) e n d ) , " , " ) ) e n d # v e r s u s u s i n g t h e p i p e o p e r a t o r d e f p r i n t ( n ) d o 1 . . n | > E n u m . m a p ( f n ( n ) - > f i z z b u z z ( n ) e n d ) | > E n u m . j o i n ( " , " ) | > I O . p u t s e n d # I n R u b y d e f p r i n t ( n ) p u t s 1 . . n . m a p d o f i z z b u z z ( n ) e n d . j o i n ( " , " ) e n d
32. Coming Back to Ruby Can I apply this in my day job?
33. Updating Records Functionally? i t ' r e l e a s e s o n e i n v i t e c r e d i t w h e n i t i s w i t h d r a w n ' d o s e n d e r = @ i n v i t e . s e n d e r e x p e c t { @ i n v i t e . w i t h d r a w ; s e n d e r . r e l o a d } . t o c h a n g e { s e n d e r . a v a i l a b l e _ i n v i t e _ c r e d i t s . l e n g t h } . b y ( 1 ) e n d i t ' r e l e a s e s o n e i n v i t e c r e d i t w h e n i t i s w i t h d r a w n ' d o s e n d e r = @ i n v i t e . s e n d e r e x p e c t { @ i n v i t e . w i t h d r a w } . t o c h a n g e { U s e r . a v a i l a b l e _ i n v i t e _ c r e d i t s ( s e n d e r . i d ) . l e n g t h } . b y ( 1 ) e n d
34. Another Attempt # f i n d t h e a u t h o r c o u n t s a u t h o r _ c o u n t s = [ ] a u t h o r _ c o u n t s _ i n d e x = - 1 c u r r e n t _ a u t h o r = ' ' f o r i i n 0 . . . c o m m i t s . l e n g t h c o m m i t = c o m m i t s [ i ] i f c o m m i t . a u t h o r = = c u r r e n t _ a u t h o r a u t h o r _ c o u n t s [ a u t h o r _ c o u n t s _ i n d e x ] [ 1 ] + = 1 e l s e c u r r e n t _ a u t h o r = c o m m i t . a u t h o r a u t h o r _ c o u n t s < < [ c o m m i t . a u t h o r , 1 ] a u t h o r _ c o u n t s _ i n d e x + = 1 e n d e n d c o m m i t s . s o r t _ b y d o | c o m m i t | c o m m i t . a u t h o r e n d . c h u n k d o | c o m m i t | c o m m i t . a u t h o r e n d . e a c h d o | a u t h o r , a u t h o r _ c o m m i t s | p u t s " # { a u t h o r } h a s # { a u t h o r _ c o m m i t s . c o u n t } c o m m i t s " e n d
35. Ruby is an OO Language, Default to OO Idioms Use functional style blocks Bottom-up versus Top-down Tell Don't Ask Read POODR by Sandi Metz My approaches to some Ruby problems have probably changed in subtle ways. Learning Elixir has been fun and will help me learn other languages (and their strengths) faster. I'm probably also better prepared to use Proc objects, the Proc#curry method, and Enumerator::Lazy objects but directly practicing them would be even better (perhaps with katas).