bar project in Crystal (that calls the foo library, implemented in Rust - https://gist.github.com/davidkellis/78bd7c65f31539b183f1b60c43339ff9)

README.md

How to run:

$ crystal run src/bar.cr
hello from crystal
Just called a Rust function from C!

shard.yml

name: bar
version: 0.1.0

authors:
  - davidkellis <davidkellis@gmail.com>

targets:
  bar:
    main: src/bar.cr

crystal: 0.26.1

license: MIT

src__bar.cr

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

@[Link(ldflags: "#{__DIR__}/../../foo/target/debug/libfoo.dylib")]
lib Foo
  fun call_from_c()
end

def main
  puts "hello from crystal"
  Foo.call_from_c
end

main