wren.cr

Crystal bindings to the Wren interpreter.

Includes additional libraries / utilities out of the box:

• wren-json

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     wren:
       github: nobodywasishere/wren.cr
   

2. Run shards install

3. Run ./src/ext/generate.sh

Usage

require "wren"

vm = Wren::VM.new

# Supports low-level interfacing with the VM

vm.bind_method("MyKlass", true, "method(_,_)") do |vm|
  a = LibWren.get_slot_double(vm, 1)
  b = LibWren.get_slot_double(vm, 2)
  LibWren.set_slot_double(vm, 0, a + b)
end

vm.interpret <<-WREN
class MyKlass {
  foreign static method(a, b)
}
WREN

puts vm.call("MyKlass", "method(_,_)", [1, 2]) # => 3.0

vm.interpret <<-WREN
  System.print(MyKlass.method(1, 2)) // => "3"
WREN

# Equivalent to above, also supports automatically creating bindings

class MyOtherKlass
  include Wren::Class

  foreign_def self.method do |a, b|
    case {a, b}
    when {Float64, Float64}
      a + b
    end
  end
end

vm.bind(MyOtherKlass)

puts MyOtherKlass.method(1, 2) # => 3.0

vm.interpret <<-WREN
  System.print(MyOtherKlass.method(1, 2)) // => "3"
WREN

Contributing

1. Fork it (https://github.com/nobodywasishere/wren.cr/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Margret Riegert - creator and maintainer