In application script hosting. How does tryfsharp.org work? - f#

Question

I am interested in the ability to have F# scripting within my app.
Having something like tryfsharp.org would be great, specifically the Intellisense capability. Is any of this available on Github somewhere? How does this work?

Answer 1

Short answer
The code used for the first cut of TryFSharp with F# 2, which includes Intellisense support, is available as a code drop. As an example Rob Pickering built an online editor for Undertone with it. I suspect the code used on the current TryFSharp site which uses F# 3 will appear in time.
TryFSharp uses Silverlight to host the F# compiler in the client's browser (F# is written in F#). It is also possible to call an instance of the F# compiler running on the server from the browser on demand, which is an approach taken by TryFs.Net and Pit.
Longer answer
There are two sides to scripting:
Editing
Execution
F# already supports editing and execution of (.fsx) script files via F# Interactive.
Editing F# Code
There's no shortage of external editors for F# code:
Visual Studio
SharpDevelop
Xamarin Studio
Emacs
Vim
TryFSharp
F# Notebook
The editor support for Xamarin Studio, Emacs and Vim is based on the open source F# Bindings project, which provides code completion.
SharpDevelop uses the open source AvalonEdit and includes syntax highlighting for F#. You can use AvalonEdit in your own projects, for example the open source Refunctor project uses it to provide F# editing inside Reflector.
There are also a couple of new editors for F# on the horizon:
Cloud Sharper - web based F# IDE
Tsumani IDE - embedded editor for Excel, Hadoop, etc.
AvalonEdit is a good place to start for a desktop based embedded editor. Once you've chosen an editor environment then you need to choose between simple syntax highlighting or more advanced integration using F# Bindings. If you suspect people will use an external editor then syntax highlighting may be sufficient.
Bring your own editor is probably the easiest place to start which just leaves execution.
Executing F# Code
Options for executing F# code:
F# CodeDOM from the F# PowerPack
F# Compiler via the F# compiler code drop or invoking fsi.exe
Compiling a snippet with the F# CodeDOM:
open Microsoft.FSharp.Compiler.CodeDom
open System.CodeDom.Compiler
let compile snippet =
use provider = new FSharpCodeProvider()
let options = CompilerParameters(GenerateInMemory=true)
provider.CompileAssemblyFromSource(options, [|snippet|])
let snippet = """
module Snippet
let x = 1
"""
let results = compile snippet