The document presents an introduction to the Crystal programming language, highlighting its features such as ease of reading and writing, efficiency, and type checking. It includes various code examples demonstrating Crystal's syntax and performance comparisons with other programming languages. Additionally, it mentions applications built with Crystal across different domains, including console applications, emulators, and web pages.

1. Buenos Aires - Crystal Meetup #1
¿Por qué Crystal? Ary Borenszweig
aborenszweig@manas.com.ar

2. ¿Por qué un lenguaje nuevo?

3. Poca ceremonia
# Crystal
puts “Hello world”
~~~
// Java
public class Main {
public static void main(String[] args) {
System.out.println(“Hola mundo!”);
}
}

4. Fácil de leer y escribir

5. Fácil de leer y escribir
def say_hello()
puts(“Hola mundo!”);
end
say_hello();

6. Fácil de leer y escribir
def say_hello()
puts(“Hola mundo!”)
end
say_hello()

7. Fácil de leer y escribir
def say_hello()
puts “Hola mundo!”
end
say_hello()

8. Fácil de leer y escribir
def say_hello
puts “Hola mundo!”
end
say_hello

9. Apariencia de un lenguaje dinámico
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(100_000)

10. Eficiente

11. Eficiente
Tiempo (s) Memoria (MB)
C++ 5.08 1.1
Crystal 6.97 1.3
Ruby 226.86 8.0
Brainfuck
https://github.com/kostya/benchmarks

12. Eficiente
Tiempo (s) Memoria (MB)
Crystal 15.87 398.1
C++ 17.72 174.5
Python 396.54 724.0
Havlak
https://github.com/kostya/benchmarks

13. Eficiente
Tiempo (s) Memoria (MB)
Crystal 0.59 3.3
Go 1.43 2.3
Erlang 1.89 17.1
Ruby 41.73 30.0
Threadring
https://github.com/kostya/crystal-benchmarks-game

14. Eficiente
Tiempo (relativo)
Java 1.8.0_66 1.00
Crystal 1.58
Ruby MRI 2.3 47.59
Are we fast yet?
http://stefan-marr.de/downloads/crystal.html

15. Chequeo de tipos

16. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(100_000)

17. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(“Ups”)

18. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(“Ups”) # Error: no overload matches
# `Int32#<` with type String

19. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(“Ups”) # Error: no overload matches
# `Int32#<` with type String

20. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(“Ups”) # Error: no overload matches
# `Int32#<` with type String

21. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(100_000)

22. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n : Int)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(100_000)

23. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n : Int)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(“Ups”)

24. Chequeo de tipos
def prime?(n)
(2..n).all? { |i| n % i != 0 }
end
def sexy_primes(n : Int)
(9..n).map { |i| {i - 6, i} }
.select { |i| i.all? { prime?(i) } }
end
puts sexy_primes(“Ups”) # Error: no overload matches
# `sexy_primes` with type String

25. Alto nivel
numbers = [1, 2, 3, 4]
puts numbers.map { |x| x + 10 } # => [11, 12, 13, 14]
puts numbers[0] + numbers[-1] # => 5
phones = {
“Ary” => “15512312312”,
“Brian” => “1545645645”,
“Juan” => “1578978978”,
}
puts phones[“Brian”] # => “1545645645”

26. Bajo nivel
ptr = Pointer(UInt8).malloc(20)
ptr.value = 10_u8
puts ptr # => Pointer(UInt8)@0x109303e00
a = 1
ptr = pointerof(a)
ptr.value = 2
puts a # => 2
buffer = uninitialized UInt8[1024]

27. Bajo nivel
lib LibC
fun rand : LibC::Int
end
puts LibC.rand # => 16807

28. ¿Por qué un lenguaje nuevo?
❖ Poca ceremonia
❖ Fácil de leer y escribir
❖ Apariencia de un lenguaje dinámico
❖ Eficiente
❖ Chequeo de tipos
❖ Alto y bajo nivel
❖ => Felicidad!

29. ¿Para qué sirve?

30. Aplicaciones de consola
❖ tlcr: https://github.com/porras/tlcr
❖ crul: https://github.com/porras/crul
❖ vicr: https://github.com/veelenga/vicr
❖ shards: https://github.com/ysbaddaden/shards

31. Emuladores
❖ nes.cr: https://github.com/romeroadrian/nes.cr
❖ rcpu: https://github.com/ddfreyne/rcpu

32. Juegos
❖ crsfml: https://github.com/BlaXpirit/crsfml
❖ crystal-gl: https://github.com/ggiraldez/crystal-gl

33. Páginas web
❖ crystalshards: https://github.com/zamith/
crystalshards
❖ play.crystal-lang.org: https://github.com/jhass/carc.in

34. Bots IRC
❖ DeBot: https://github.com/jhass/DeBot

35. Compiladores
❖ Crystal: https://github.com/manastech/crystal

36. ¡Gracias!
Ary Borenszweig
email: aborenszweig@manas.com.ar
@asteritetwitter: