Hey all,
This is a small and simple library I am developing, that will be part in a larger whole of libraries to hopefully at some point allow nice, functional native Graphical User Interfaces to be made from within elixir.
People who know about Elm: This is basically what Elm does as well.
GenFRP
GenFRP is a library that allows for programming in elixir using the
Functional Reactive Programming method.
This is a way to store and dispatch information that is very readable and extensible.
The idea is as follows:
- Your FRP module contains
use GenFRP, initial_state: some_useful_starting_state. (some_useful_starting_statecan be anything you wish, of course) - It implements the
update(state, event) :: statefunction. - It implements the
render(state, last_rendered_state) :: anyfunction.
update is called whenever an event is sent to the GenFRP process by using GenFRP.send_event(frp_pid, whatever_you_want_to_send).
render is called whenever you want to know its current state (in some representation format that is useful for the outside world, i.e. rendered).
GenFRP uses a very simple caching mechanism to ensure that render is only invoked when the internal state has changed since its last invocation.
Here is a very simple example (which can be found as GenFRP.Example.Map as well)
defmodule GenFRP.Example.Map do
use GenFRP, initial_state: %{}
def update(state, [{key, val}]) do
Map.put(state, key, val)
end
def update(state, event) do
IO.puts "Unrecognized event passed to `#{inspect(__MODULE__)}.update/2`: #{event}"
end
@doc """
Returns the key-value pairs as strings, separated over multiple lines, in alphabetical order.
"""
def render(state, last_rendered_state) do
Enum.map(state, fn {key, val} ->
"`#{key}`: `#{val}`"
end)
end
Enum.join("\n")
end
This can be used as follows:
{:ok, pid} = GenFRP.start_link(GenFRP.Example.Map)
# ... maybe some other code here...
GenFRP.send_event(pid, {:foo, :bar})
# ... maybe some more code here...
GenFRP.send_event(pid, {:baz, 42})
# ... maybe yet some other code here...
GenFRP.render(pid)
"`foo`: `bar`
``baz`: `42`
"
This is the first, 0.1.0 version release. I wanted to get this out quickly, to get some feedback from the community.
Expect things to be still somewhat unfinished, and don’t worry: I will run Credo on the code to make it nicer 
.
But: any feedback is greatly appreciated. Is this programming interface understandable? Are there things that the library is glaringly lacking?
Thank you,
~Qqwy
!
.
.
