davidgrenier

#r "System.Management"
open System.Management

do
    use ma = new ManagementObjectSearcher("Select * from Win32_Processor")

    for item in ma.Get() do
        try
            printfn "%A" item.["NumberOfCores"]
        with _ -> ()

davidgrenier

let cell init =
    MailboxProcessor.Start(fun inbox ->
        let rec loop n =
            async {
                let! result = inbox.Receive()
                printfn "Received %d" result
                return! loop result
            }

        loop init

davidgrenier

let inline parse str = (^a: (static member Parse: string -> ^a) (str))

let inline tryParse str =
    let mutable value = Unchecked.defaultof<_>
    let result = (^a: (static member TryParse: string * byref< ^a > -> bool) (str, &value))
    result, value

(tryParse "3": bool * int)
(tryParse "2.3": bool * float)
(tryParse "2.3": bool * decimal)

davidgrenier

#r @"C:\Projects\Lib\System.Reactive.Interfaces.dll"
#r @"C:\Projects\Lib\System.Reactive.Core.dll"
#r @"C:\Projects\Lib\System.Reactive.Linq.dll"

open System
open System.Linq
open System.Reactive.Subjects
open System.Reactive.Linq
 
let run n m =

davidgrenier

//Hi Julie, I liked your article and couldn't resist offering some possible improvements. I don't know
//what all the formulae mean but F#'s pattern matching is pretty powerful but also extensible and can
//be used to greatly improve readability and your chances of getting the code right in the first go.
//
//Below you can see the definition of two Active Pattern to extend F#'s pattern matching with a way
//to extract information from simple values, in this case floats.

let (|GreaterThan|_|) num = function
    | value when value > num -> Some ()
    | _ -> None

davidgrenier

query {
    for order in db.Orders do
    let status =
        match order.Status with
        | 0 | 1 -> "Cancelled/Returned"
        | _ -> "Valid"
    where (status = "Valid")
    select order
}

davidgrenier

module Order =
    type T = Order of int

    let get (db: DataContext) id =
        query {
            for order in db.Orders do
            where (order.Id = id)
            select (Order id)
            exactlyOne
        }

davidgrenier

type FileChange =
    | Changed of string
    | Deleted of string
    | Created of string
    | Renamed of string * string
 
let watch folder =
    async {
        use fsw = new System.IO.FileSystemWatcher(folder, "*.fsx", EnableRaisingEvents = true)
 

davidgrenier

let (|Empty|_|) = function
    | xs when Set.isEmpty xs -> Some ()
    | _ -> None

[
    "rule1", ["192"; "193"]
    "rule2", ["193"; "194"]
    "rule3", ["194"; "195"]
]
|> Seq.fold (fun data (rule, dst) ->

davidgrenier

let data =
    query {
        for packet in communicator.ReceivePackets() do
        // where (not packet.IsValid)
        select packet
    }