Objectives

What do we want to do today?

The Crystal Programming Language

What is this?

https://crystal-lang.org/

web playground: https://play.crystal-lang.org/#/cr

native compilation (via LLVM)

heavily Ruby-inspired syntax

statically type-checked, type-inferenced

non-nillable types (compile-time nil checks)

macro metaprogramming system

The Crystal Programming Language

An HTTP server

require "http/server"

server = HTTP::Server.new do |context|
  context.response.content_type = "text/plain"
  context.response.print "Hello world! The time is #{Time.local}"
end

address = server.bind_tcp 8080
puts "Listening on http://#{address}"
server.listen

Getting Started with Crystal

Installation

https://crystal-lang.org/install/

Online playground: https://play.crystal-lang.org/#/cr

Download: https://crystal-lang.org/install/from_targz

Package managers:

Homebrew/Linuxbrew: brew install crystal-lang

Ubuntu: curl -fsSL https://crystal-lang.org/install.sh | sudo bash

From sources: https://crystal-lang.org/install/from_sources/

self-hosting, so you need Crystal to build Crystal

Getting Started with Crystal

Create a project

crystal init app hello

Hello, world: src/hello.cr

# TODO: Write documentation for `Hello`
module Hello
  VERSION = "0.1.0"

  # TODO: Put your code here
end

Run

crystal run src/hello.cr

Compile

crystal build src/hello.cr; ./hello

Summary

So... now what?

Credentials

Who is this guy?

Architect, Engineering Manager/Leader, "force multiplier"

http://www.newardassociates.com

http://blogs.newardassociates.com

Sr Distinguished Engineer, Capital One

Educative (http://educative.io) Author

Performance Management for Engineering Managers

Books

Developer Relations Activity Patterns (w/Woodruff, et al; APress, forthcoming)

Professional F# 2.0 (w/Erickson, et al; Wrox, 2010)

Effective Enterprise Java (Addison-Wesley, 2004)

SSCLI Essentials (w/Stutz, et al; OReilly, 2003)

Server-Based Java Programming (Manning, 2000)