Fsharpy

Access F# interactive (FSI) from Elixir.

Getting F#

FSharpy requires that dotnet or dotnet-core be installed and in your path. You can install dotnet using asdf.

$ asdf plugin add dotnet-core
$ asdf install dotnet-core 5.0.203
$ asdf global dotnet-core 5.0.203

... or by following the instructions here: https://dotnet.microsoft.com/download

Usage from IEX

To start an Fsharpy session...

iex> {:ok, p} = Fsharpy.start_link
{:ok, #PID<0.142.0>}

Once an Fsharpy session has been started, you can use the print function to send code to be evaluated in F# and have the results printed to IEX.

iex> Fsharpy.print p, "let x = 21 * 2"

F#: val x : int = 42
:ok

iex> Fsharpy.print p, "#help"

F#: F# Interactive directives:
F#:
F#:     #r "file.dll";;        Reference (dynamically load) the given DLL
F#:     #I "path";;            Add the given search path for referenced DLLs
F#:     #load "file.fs" ...;;  Load the given file(s) as if compiled and referenced
F#:     #time ["on"|"off"];;   Toggle timing on/off
F#:     #help;;                Display help
F#:     #quit;;                Exit
F#:
F#:   F# Interactive command line options:
F#:
F#:       See 'fsharpi --help' for options
:ok

To evaluate F# code and get results that can be used programatically in Elixir you can use the eval function

iex> Fsharpy.eval p, "let x = 10"
[%{"x" => 10}]

iex> Fsharpy.eval p, "let y = x + 5"
[%{"y" => 15}]

iex> [map] = Fsharpy.eval p, "[1;2;3;4;5] |> List.map(fun n -> n * x)"
[%{"it" => [10, 20, 30, 40, 50]}]

iex> map["it"] |> Enum.reverse
[50, 40, 30, 20, 10]

To shut down the Fsharpy session

iex>  Fsharpy.quit p
:ok