January 2019
Intermediate to advanced
246 pages
5h 23m
English
Content preview from Programming Crystal
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Appendix 1: Setting Up a Crystal Environment
Your Turn 1
a. hello_world.cr:
$ crystal build hello_world.cr # size: 1.1MB
$ crystal build hello_world.cr --release # size: 802KB (Use –release –no-debug if –release doesn’t work for you.)
$ crystal build hello_world.cr --debug # size: 1.4MB
b. $ crystal build test.cr --error-trace
c. Put the code within single quotes: $ crystal eval ’puts "Greetings world!"’ # => Greetings world!
d. $ crystal build hello_world.cr --emit llvm-ir/ (see file hello_world.ll)
$ crystal build hello_world.cr --emit asm (see file hello_world)
e. $ crystal env gives as output:
| | CRYSTAL_CACHE_DIR="/home/username/.cache/crystal" |
| | CRYSTAL_PATH="lib:/opt/crystal/src" |
| | CRYSTAL_VERSION="0.23.1" |
f. A Crystal REPL: Clone the repository ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.