F# Async problem.
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Published on 2010-06-13T06:39:33Z
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2010/06/13
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Hi, I've written a dummy http server as an exercise in F#.
I'm using Mono 2.4.4 on Ubuntu 10.04 x86_64, with MonoDevelop.
The following code fails to compile with the error:
Error FS0039: The field, constructor or member 'Spawn' is not defined (FS0039)
Could someone try this in VisualStudio please, I don't know whether this is a Mono problem, or my problem.
I have tried several Async examples from the F# book, and they also all produce similar messages about Async.* methods.
Thanks,
Chris.
#light
open System
open System.IO
open System.Threading
open System.Net
open System.Net.Sockets
open Microsoft.FSharp.Control.CommonExtensions
printfn "%s" "Hello World!"
let headers = System.Text.Encoding.ASCII.GetBytes("HTTP/1.0 200 OK\r\nContent-Type: text/html; charset=UTF-8\r\nContent-Length: 37\r\nDate: Sun, 13 Jun 2010 05:30:00 GMT\r\nServer: FSC/0.0.1\r\n\r\n")
let content = System.Text.Encoding.ASCII.GetBytes("<html><body>Hello World</body></html>")
let serveAsync (client : TcpClient) =
async { let out = client.GetStream()
do! out.AsyncWrite(headers)
do! Async.Sleep 3000
do! out.AsyncWrite(content)
do out.Close()
}
let http_server (ip, port) =
let server = new TcpListener(IPAddress.Parse(ip),port)
server.Start()
while true do
let client = server.AcceptTcpClient()
printfn "new client"
Async.Spawn (serveAsync client)
http_server ("0.0.0.0", 1234)
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