Golo, the Tiny Language that gives super powers

Specific version for @DevTalksRo

Transcript

1. Golo, the Tiny Language that gives super powers
2. Philippe Charrière > Technical “evangelist” & CSO @Clever_Cloud > Core committer for the eclipse/golo-lang project U@k33g_org / O @k33g
3. What is Golo?
4. A dynamic language for the JVM Built from the first day with invokedynamic Light (~700 kb) and fast (in a dynamic context) A research project by Julien Ponge http://golo-lang.org @jponge
6. Why such a title? “The Tiny Language that gives super powers”
7. Thanks to Golo… I learned to read the Java doc I progressed in Java (I wasn’t a Java Ninja) I learned how to participate in an opensource project I do things I didn’t do before
8. Agenda We will not have enough time to “do the whole” of Golo
9. we are going to talk about: Golo’s simplicity: hello world, … some Golo’s specificities: DynamicObjects, Structures,… Functional Programming: Optional, Result,… Golo ❤ Java: Vert-x, … Augmenting Golo: add features to Golo
10. Golo’s Simplicity Quick landscape
11. Golo install Download Golo: http://golo-lang.org/download/ Unzip it export GOLO_HOME=~/golo-lang export PATH=$GOLO_HOME/bin:$PATH export PATH=~/:$PATH
12. Golo install You can build Golo git clone git@github.com:eclipse/golo-lang.git ./gradlew installDist
13. My first “hello world!”
14. Hello world module hello.world function main = |args| { println("Hello ") }
15. Hello world module hello.world function main = |args| { println("Hello ") }
16. Hello world module hello.world function main = |args| { println("Hello ") }
17. Hello world module hello.world function main = |args| { println("Hello ") }
18. How to run Golo code?
19. Run some Golo Code You can compile and run Or create Jar files applications (or Libraries) but…
20. Run Golo code as a script golo golo --classpath libs/*.jar --files imports/*.golo main.golo
21. Run Golo code as a script golo golo --classpath libs/*.jar --files imports/*.golo main.golo
22. Run Golo code as a script golo golo --classpath libs/*.jar --files imports/*.golo main.golo
23. Run Golo code as a script golo golo --classpath libs/*.jar --files imports/*.golo main.golo
24. Modules & Functions
25. Modules & Functions # my.lib.golo module my.lib function hello = |name| { return "Hello " + name } # short version function hi = |name| -> "Hi " + name # main.golo module myApp import my.lib function main = |args| { let name = "Baby Groot" println(hello(name)) println(hi(name)) }
26. Modules & Functions # my.lib.golo module my.lib function hello = |name| { return "Hello " + name } # short version function hi = |name| -> "Hi " + name # main.golo module myApp import my.lib function main = |args| { let name = "Baby Groot" println(hello(name)) println(hi(name)) }
27. Modules & Functions # my.lib.golo module my.lib function hello = |name| { return "Hello " + name } # short version function hi = |name| -> "Hi " + name # main.golo module myApp import my.lib function main = |args| { let name = "Baby Groot" println(hello(name)) println(hi(name)) }
28. Modules & Functions # my.lib.golo module my.lib function hello = |name| { return "Hello " + name } # short version function hi = |name| -> "Hi " + name # main.golo module myApp import my.lib function main = |args| { let name = "Baby Groot" println(hello(name)) println(hi(name)) }
29. Lambdas
30. Lambdas module lambdas function main = |args| { let add = |a, b| { return a + b } # compact version let addOne = |value| -> value + 1 println( add(40, 2) ) # 42 println( addOne(41) ) # 42 }
31. Lambdas module lambdas function main = |args| { let add = |a, b| { return a + b } # compact version let addOne = |value| -> value + 1 println( add(40, 2) ) # 42 println( addOne(41) ) # 42 }
32. Lambdas module lambdas function main = |args| { let add = |a, b| { return a + b } # compact version let addOne = |value| -> value + 1 println( add(40, 2) ) # 42 println( addOne(41) ) # 42 }
33. Some control & loop constructions
34. Control Structures
35. Control structures module control function main = |args| { let fourtyTwo = 42 if fourtyTwo is 42 { println("") } else { println("") } }
36. Control structures module control function main = |args| { let isEqualTo42 = |value| { case { when value is 42 { return " good" } when value > 42 { return " too big" } otherwise { return " too little" } } } println(isEqualTo42(42)) # good println(isEqualTo42(24)) # too little println(isEqualTo42(84)) # too big }
37. Loop Structures
38. Loop structures module loops function main = |args| { var counter = 0 while (counter < 4) { counter = counter + 1 } println(counter) # 4 }
39. Loop structures module loops function main = |args| { foreach item in [1, 2, 3, 4, 5] { if item < 3 { println(item) } } foreach item in [1, 2, 3, 4, 5] when item < 3 { println(item) } }
40. Loop structures with a guard module loops function main = |args| { foreach item in [1, 2, 3, 4, 5] { if item < 3 { println(item) } } foreach item in [1, 2, 3, 4, 5] when item < 3 { println(item) } }
41. Java types
42. Java types module javatypes function main = |args| { let vegetables = java.util.LinkedList() # no new keyword vegetables: add("") # colon notation vegetables: add("") vegetables: add("") println(vegetables) # [, , ] let mixedSalad = vegetables : stream() : map( |ingredient| -> java.lang.String.join(ingredient, ingredient, ingredient) ) : reduce("", |acc, next| -> acc + next) println(mixedSalad) # } # dot notation
43. Java types module javatypes function main = |args| { let vegetables = java.util.LinkedList() # no new keyword vegetables: add("") # colon notation vegetables: add("") vegetables: add("") println(vegetables) # [, , ] let mixedSalad = vegetables : stream() : map( |ingredient| -> java.lang.String.join(ingredient, ingredient, ingredient) ) : reduce("", |acc, next| -> acc + next) println(mixedSalad) # } # dot notation
44. Java types module javatypes function main = |args| { let vegetables = java.util.LinkedList() # no new keyword vegetables: add("") # colon notation vegetables: add("") vegetables: add("") println(vegetables) # [, , ] let mixedSalad = vegetables : stream() : map( |ingredient| -> java.lang.String.join(ingredient, ingredient, ingredient) ) : reduce("", |acc, next| -> acc + next) println(mixedSalad) # } # dot notation
45. Simpler way: Collection literals module javatypes function main = |args| { let vegetables = list["", "", ""] let mixedSalad = vegetables : map(|ingredient| -> "": join(ingredient,ingredient,ingredient)) : reduce("", |acc, next| -> acc + next) println(mixedSalad) # } java.util.LinkedList()
46. Simpler way: Collection literals module javatypes function main = |args| { let vegetables = list["", "", ""] let mixedSalad = vegetables : map(|ingredient| -> ingredient: join(ingredient,ingredient)) : reduce("", |acc, next| -> acc + next) println(mixedSalad) # }
47. Golo’s Specificities
48. no class with Golo❗
49. DynamicObjects
50. DynamicObject module clark function main = |args| { let clark = DynamicObject() : firstName("Clark"): lastName("Kent") : define("hello", |this| { println("Hello, I'm " + this: firstName()) return this }) : define("say", |this, message| { println(message) return this }) clark: hello(): say("hi!") # Hello, I'm Clark\n hi! clark: firstName("CLARK") clark: hello() # Hello, I'm CLARK clark: define("yo", |this| -> println("yo!")) }
51. DynamicObject module clark function main = |args| { let clark = DynamicObject() : firstName("Clark"): lastName("Kent") : define("hello", |this| { println("Hello, I'm " + this: firstName()) return this }) : define("say", |this, message| { println(message) return this }) clark: hello(): say("hi!") # Hello, I'm Clark\n hi! clark: firstName("CLARK") clark: hello() # Hello, I'm CLARK clark: define("yo", |this| -> println("yo!")) }
52. DynamicObject module clark function main = |args| { let clark = DynamicObject() : firstName("Clark"): lastName("Kent") : define("hello", |this| { println("Hello, I'm " + this: firstName()) return this }) : define("say", |this, message| { println(message) return this }) clark: hello(): say("hi!") # Hello, I'm Clark\n hi! clark: firstName("CLARK") clark: hello() # Hello, I'm CLARK clark: define("yo", |this| -> println("yo!")) }
53. Less dynamic but powerful: Structures
54. Structures module doeFamiliy struct human = { firstName, lastName } function main = |args| { # simple constructor let jane = human("Jane", "Doe") # constructor, then setters let john = human(): firstName("John"): lastName("Doe") println("hello we are " + jane: firstName() + " " + jane: lastName() + " and " + john: firstName() + " " + john: lastName() ) println(jane oftype doeFamiliy.types.human.class) # true }
55. Structures module doeFamiliy struct human = { firstName, lastName } function main = |args| { # simple constructor let jane = human("Jane", "Doe") # constructor, then setters let john = human(): firstName("John"): lastName("Doe") println("hello we are " + jane: firstName() + " " + jane: lastName() + " and " + john: firstName() + " " + john: lastName() ) println(jane oftype doeFamiliy.types.human.class) # true }
56. Augmenting Structure
57. Structures & Augmentations module doeFamiliy struct human = { firstName, lastName } augment human { function hello = |this| { println(this: firstName() + ": Hello!") } function hello = |this, message| { println(this: firstName() + ": Hello! " + message) } } function main = |args| { let jane = human("Jane", "Doe") jane: hello() # Jane: Hello! jane: hello("How are you doing?") # Jane: Hello! How are you doing? }
58. Structures & Augmentations module doeFamiliy struct human = { firstName, lastName } augment human { function hello = |this| { println(this: firstName() + ": Hello!") } function hello = |this, message| { println(this: firstName() + ": Hello! " + message) } } function main = |args| { let jane = human("Jane", "Doe") jane: hello() # Jane: Hello! jane: hello("How are you doing?") # Jane: Hello! How are you doing? }
59. Structures & named Augmentations module doeFamiliy struct human = { firstName, lastName } struct dog = { name } augmentation eat = { function eat = |this, something| -> println("I'm eating " + something) } augment human with eat augment dog with eat function main = |args| { let jane = human("Jane", "Doe") let cookie = dog("Cookie") jane: eat("") # I'm eating cookie: eat("") # I'm eating }
60. Golo & Functional Programming
61. NPE Java -> Optional Haskell -> Maybe Golo -> Option
62. NPE module nomore_npe struct buddy = { id, avatar } function main = |args| { let buddies = list[buddy(1, ""), buddy(2, ""), buddy(3, "")] # println(buddies: find(|buddy| -> buddy: id(): equals(3)): avatar()) # java.lang.NullPointerException println(buddies: find(|buddy| -> buddy: id(): equals(4)): avatar()) }
63. Option() / Some / None function main = |args| { let buddies = list[buddy(1, ""), buddy(2, ""), buddy(3, "")] let getBuddy = |id| -> Option( buddies: find(|buddy| -> buddy: id(): equals(id)) ) let maybePanda = getBuddy(2) let maybeNobody = getBuddy(4) println( maybePanda ) # Optional[struct buddy{id=2, avatar=}] println( maybeNobody ) # Optional.empty println( maybePanda: isSome() ) # true println( maybeNobody: isNone() ) # true println( maybePanda: orElse(buddy(0, "")) ) # struct buddy{id=2, avatar=} println( maybeNobody: orElse(buddy(0, "")) ) # struct buddy{id=0, avatar=} }
64. Option() / Some / None function main = |args| { let buddies = list[buddy(1, ""), buddy(2, ""), buddy(3, "")] let getBuddy = |id| -> Option( buddies: find(|buddy| -> buddy: id(): equals(id)) ) let maybePanda = getBuddy(2) let maybeNobody = getBuddy(4) println( maybePanda ) # Optional[struct buddy{id=2, avatar=}] println( maybeNobody ) # Optional.empty println( maybePanda: isSome() ) # true println( maybeNobody: isNone() ) # true println( maybePanda: orElse(buddy(0, "")) ) # struct buddy{id=2, avatar=} println( maybeNobody: orElse(buddy(0, "")) ) # struct buddy{id=0, avatar=} }
65. Option() / Some / None function main = |args| { let buddies = list[buddy(1, ""), buddy(2, ""), buddy(3, "")] let getBuddy = |id| -> Option( buddies: find(|buddy| -> buddy: id(): equals(id)) ) let maybePanda = getBuddy(2) let maybeNobody = getBuddy(4) println( maybePanda ) # Optional[struct buddy{id=2, avatar=}] println( maybeNobody ) # Optional.empty println( maybePanda: isSome() ) # true println( maybeNobody: isNone() ) # true println( maybePanda: orElse(buddy(0, "")) ) # struct buddy{id=2, avatar=} println( maybeNobody: orElse(buddy(0, "")) ) # struct buddy{id=0, avatar=} }
66. Option() / either() function main = |args| { let buddies = list[buddy(1, ""), buddy(2, ""), buddy(3, "")] let getBuddy = |id| -> Option( buddies: find(|buddy| -> buddy: id(): equals(id)) ) getBuddy(2) : either( |buddy| { println("Hello "+ buddy: avatar()) }, # Hello { println(" ouch❗") } ) }
67. Result and Error
68. Result / Error module nomore_error import gololang.Errors function main = |args| { let divide = |a, b| { try { return Result(a/b) } catch(e) { return Error(e: message()) } } println( divide(84, 2) ) # Result.value[42] println( divide(84, 0) ) # Result.error[ java.lang.RuntimeException: / by zero] }
69. Result / Error / trying() / either() module nomore_error import gololang.Errors function main = |args| { let divide = |a, b| -> trying({ return a/b }) divide(84, 0): either( |result| -> println(": " + result), |error| -> println(": " + error: message()) # : / by zero ) }
70. Result / Error / trying() / either() module nomore_error import gololang.Errors function main = |args| { let divide = |a, b| -> trying({ return a/b }) divide(84, 0): either( |result| -> println(": " + result), |error| -> println(": " + error: message()) # : / by zero ) }
71. Golo ❤ Java
72. Golo ❤ Java package acme; import java.lang.String; import java.lang.System; public class Toon { private String name; public String getName() { return name; } public void setName(String value) { name = value; } public Toon(String name) { this.name = name; } public static Toon getInstance(String name) { return new Toon(name); } public void hug(Toon toon) { System.out.println("I ❤ " + toon.name); } } module toons import acme function main = |args| { let buster = Toon("Buster") # no new buster: name("Buster Bunny") println(buster: name()) let elmira = Toon.getInstance("elmira") elmira: hug(buster) }
73. Golo ❤ Java package acme; import java.lang.String; import java.lang.System; public class Toon { private String name; public String getName() { return name; } public void setName(String value) { name = value; } public Toon(String name) { this.name = name; } public static Toon getInstance(String name) { return new Toon(name); } public void hug(Toon toon) { System.out.println("I ❤ " + toon.name); } } module toons import acme function main = |args| { let buster = Toon("Buster") # no new buster: name("Buster Bunny") println(buster: name()) let elmira = Toon.getInstance("elmira") elmira: hug(buster) }
74. Golo ❤ Java package acme; import java.lang.String; import java.lang.System; public class Toon { private String name; public String getName() { return name; } public void setName(String value) { name = value; } public Toon(String name) { this.name = name; } public static Toon getInstance(String name) { return new Toon(name); } public void hug(Toon toon) { System.out.println("I ❤ " + toon.name); } } module toons import acme function main = |args| { let buster = Toon("Buster") # no new buster: name("Buster Bunny") println(buster: name()) let elmira = Toon.getInstance("elmira") elmira: hug(buster) }
75. and …
76. Golo ✨⚡ Java module toons import acme augment acme.Toon { function hey = |this, message| { println(this: name() + ": " + message) } } function main = |args| { let buster = Toon("Buster") buster: hey("I'm a ") }
77. Golo and the other frameworks
78. Simplification with Golo
79. Java web application with Vert-x int httpPort = 8080; Vertx vertx = Vertx.vertx(); HttpServer server = vertx.createHttpServer(); Router router = Router.router(vertx); router.route().handler(BodyHandler.create()); router.get("/about").handler(routingContext -> { routingContext.response() .putHeader("content-type", "application/json;charset=UTF-8") .end((new JsonObject().put("about", " hello from Golo")).toString()); }); router.post("/hello").handler(routingContext -> { String name = routingContext.getBodyAsJson().getString("name"); routingContext.response() .putHeader("content-type", "application/json;charset=UTF-8") .end((new JsonObject().put("message", " Hello " + name)).toString()); }); server.requestHandler(router::accept).listen(httpPort);
80. A few augmentations later…
81. Simplify Vert-x let httpPort = 8080 let server = createHttpServer() let router = getRouter() router: get("/about", |context| { context: response(): djson(): about(" hello from Golo"): send() }) router: post("/hello", |context| { let data = context: dbody() let name = data: name() context: response(): djson(): message(" Hello " + name): send() }) startHttpServer(server, router, httpPort, "/*")
82. some of the augmentations augment io.vertx.ext.web.Router { function get = |this, uri, handler| { return this: get(uri): handler(handler) } function post = |this, uri, handler| { return this: post(uri): handler(handler) } } augment io.vertx.core.http.HttpServerResponse { function djson = |this| { this: putHeader("content-type", "application/json;charset=UTF-8") let d = DynamicObject() d: define("send", |self| { this: end(JSON.stringify(self), "UTF-8") }) return d } } augment io.vertx.ext.web.RoutingContext { function dbody = |this| -> JSON.toDynamicObjectFromJSONString(this: getBodyAsString()) }
83. Simplify Vert-x - Functional way let httpPort = Integer.parseInt(System.getenv(): get("PORT") orIfNull "8080") let server = createHttpServer() let router = getRouter() router: get("/about", |context| { context: response(): djson(): about(" hello from Golo"): send() }) router: post("/hello", |context| { trying({ let data = context: dbody() return data: name() }) : either( |name| -> context: response(): djson(): message(" Hello " + name): send(), |error| -> context: response(): djson(): error(" " + error: message()): send() ) }) startHttpServer(server, router, httpPort, "/*")
84. the source code https://github.com/golo-x/golo-x-web
85. Augmenting Golo
86. I am a superhero I’m not a real Java Developer I ❤ JavaScript and Node But I made (accepted) PR on the Golo project
87. It’s very easy to add features to Golo 3 ways Java Golo Invokedynamic
88. It’s very easy to add features to Golo 3 ways Java Golo Invokedynamic
89. the Golo project https://github.com/eclipse/golo-lang
92. Demo
93. I do fun “things” with Golo
95. IOT & MQTT experiments the benefit of the entire Java Ecosystem easy experiments https://github.com/golo-x/golo-x-mqtt
96. Jarvis-CI https://github.com/k33g/jarvis-ci SparkJava + eGit ⚠ V0
97. GolOctokit GitHub API https://github.com/k33g/goloctokit
98. IndyBot Slack RocketChat https://github.com/bots-squad/indybot
99. Microservices https://github.com/wey-yu/poks-server https://github.com/wey-yu/poks-service https://github.com/wey-yu/poks-consumer https://github.com/wey-yu/poks-core-libs
100. Thank you very much to you and devtalks
101. One more thing: https://tech.io
102. The end. Any Questions? (not too hard)