dungpa

type Direction = 
  | Up
  | Down
  | Left
  | Right
  override this.ToString() = 
    match this with
    | Up -> "Up"
    | Down -> "Down"
    | Left -> "Left"

dungpa

type Example() =
    member __.Getter = doComputation()

// It's clearer if you use the long syntax:

type Example() =
    member __.Getter with get() = doComputation()

// What you probably wanted to do is:

dungpa

type TickTack = Tick | Tack

let ticker x =
    match x with
    | Tick -> printfn "Tick"
    | Tock -> printfn "Tock"
    | Tack -> printfn "Tack"

ticker Tick
ticker Tack

dungpa

let main() =
    let myIdent = "something ..."
    ...
    ...
    ...
    let myFunc() =
        let myIdent = "something else ..."
        ...
        ...
        myIdent

dungpa

async {
  let wc = new WebClient()
  let html = wc.DownloadString(uri)
  printfn "%s" html }

// To make code in F# async workflow actually asynchronous, 
// we need to use a primitive operation of type Async<'T> 
// (implemented usually in the F# library as an extension) and call it using let! or do!:

async {

dungpa

let plusOne (s : seq<_>) =
    let e = s.GetEnumerator()
    seq {
        while e.MoveNext() do
            yield e.Current + 1
    }

let r = plusOne [1; 2; 3]
printfn "%A" r // prints [2; 3; 4]
printfn "%A" r // prints []

dungpa

let func = 
    printfn "hi"
    1

// vs.

let func() = 
    printfn "hi"
    1

dungpa

let rec loop () = async {
  do! Async.Sleep(1000)
  do! loop() } // Wrong!

// In order to write tail-recursive calls in F# async workflows, we should use return!:

let rec loop () = async {
  do! Async.Sleep(1000)
  return! loop() } // Correct :-)

dungpa

    // Preassign the divider with some configurations.
    member x.preassignBB(level, threadId) =
        for l in 1..level do
            if threadId &&& (pown 2 l) <> 0 then
                path.[depth] <- 1uy
                totalValues.[1] <- totalValues.[1] + itemValues.[depth]
                totalUnassigned <- totalUnassigned - itemValues.[depth]
                depth <- depth + 1        
            else
                path.[depth] <- 0uy

dungpa

    // Using branch and bound method to prune unused branches.
    member x.divideBB() =
        if depth >= numItems then
            if abs(totalValues.[0] - totalValues.[1]) < bestDifference then
                Array.Copy(totalValues, bestTotalValues, size)
                bestDifference <- abs(totalValues.[0] - totalValues.[1])
            else ()            
        elif abs(totalValues.[0] - totalValues.[1]) - totalUnassigned <= bestDifference then                       
            for i in 0..1 do
                x.selectBB(i)