A language for humans and computers - Home / HN v1.0.0

#!/usr/bin/env crystal
puts "Hello World!"

• Embed Crystal code directly in Ruby / HN - have ruby generate crystal code from ruby code and then invoke it.

Creating a project or library

crystal init app <name>         # create app/lib project
shards                          # edit shards.yml/ then install shard
crystal [build|[run]] main.cr   # compile & execute main

Installation Notes

contrary to doc keys.gnupg.net is not reachable, use pgp.mit.edu instead.

Lang

• annotation

Standard library

• Array
  • doc / ruby
• Running a child process
• Iterate over directory

Shards (Gems)

• Writing a shard.yml
  • –ignore-crystal-versionx
• CrystalShards

C bindings

Crystal allows you to bind to existing C libraries without writing a single line in C.

• C++ binding

Overall perfs

• Go vs Crystal Performance
• Crystal lang vs NodeJS vs Golang http benchmark

Forum

• Crystal Forum

References

• Crystal for Rubyists
• Roadmap

see also

• Crystal vs Go: Notes and Reflections