.About-FSharpx.Extras.md

FSharpx.Extras

.build.ps1

<#
.Synopsis
	Build script (https://github.com/nightroman/Invoke-Build)
#>

[CmdletBinding()] param()

task Init {
	exec {paket.exe install --only-referenced}
}

task Kill Clean, {
	Remove-Item -Force -Recurse -ErrorAction 0 @(
		'packages'
		'paket.lock'
	)
}

task Clean {
	Remove-Item -Force -Recurse -ErrorAction 0 -Path bin, obj
}

.gitignore

*.ini
*.nupkg
*.sln
.vs
AssemblyInfo.fs
bin
obj
packages
paket.lock
z*
Turtle

fsExtras.fsproj

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <SchemaVersion>2.0</SchemaVersion>
    <ProjectGuid>ffcbd9e5-2549-4a4c-bc07-d7edd3fca6d9</ProjectGuid>
    <OutputType>Exe</OutputType>
    <RootNamespace>fsExtras</RootNamespace>
    <AssemblyName>fsExtras</AssemblyName>
    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
    <TargetFSharpCoreVersion>4.4.0.0</TargetFSharpCoreVersion>
    <Name>fsExtras</Name>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <Tailcalls>false</Tailcalls>
    <OutputPath>bin\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <WarningLevel>3</WarningLevel>
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DocumentationFile>bin\Debug\fsExtras.XML</DocumentationFile>
    <Prefer32Bit>true</Prefer32Bit>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <Tailcalls>true</Tailcalls>
    <OutputPath>bin\Release\</OutputPath>
    <DefineConstants>TRACE</DefineConstants>
    <WarningLevel>3</WarningLevel>
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DocumentationFile>bin\Release\fsExtras.XML</DocumentationFile>
    <Prefer32Bit>true</Prefer32Bit>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="mscorlib" />
    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
      <Private>True</Private>
    </Reference>
    <Reference Include="System" />
    <Reference Include="System.Core" />
    <Reference Include="System.Numerics" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="ReaderStack.fs" />
    <Compile Include="StateQueue.fs" />
    <Compile Include="StringBuilder.fs" />
    <Compile Include="InterfaceState.fs" />
    <Compile Include="InterfaceReader.fs" />
    <Compile Include="Program.fs" />
  </ItemGroup>
  <PropertyGroup>
    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
  </PropertyGroup>
  <Choose>
    <When Condition="'$(VisualStudioVersion)' == '11.0'">
      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
      </PropertyGroup>
    </When>
    <Otherwise>
      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
      </PropertyGroup>
    </Otherwise>
  </Choose>
  <Import Project="$(FSharpTargetsPath)" />
  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
       Other similar extension points exist, see Microsoft.Common.targets.
  <Target Name="BeforeBuild">
  </Target>
  <Target Name="AfterBuild">
  </Target>
  -->
  <Choose>
    <When Condition="$(TargetFrameworkIdentifier) == '.NETFramework' And $(TargetFrameworkVersion) == 'v4.5'">
      <ItemGroup>
        <Reference Include="FSharpx.Extras">
          <HintPath>packages\FSharpx.Extras\lib\net45\FSharpx.Extras.dll</HintPath>
          <Private>True</Private>
          <Paket>True</Paket>
        </Reference>
      </ItemGroup>
    </When>
  </Choose>
</Project>

InterfaceReader.fs


module InterfaceReader
open FSharpx.Reader

type It =
    abstract Do1 : unit -> unit
    abstract Inc : int -> int

let do1 (it:It) =
    it.Do1 ()

let inc i (it:It) =
    it.Inc i

let get (it:It) =
    it

type Imp() =
    interface It with
        member x.Do1 () = printfn "Do1"
        member x.Inc i = i + 1

let test1 () =
    let work = reader {
        do! do1

        // get the reader
        let! it = get
        printfn "%A" it

        // get the reader v2
        let! it2 = fun x -> x
        printfn "%A" it2

        // get the reader v3, best
        let! it3 = id
        printfn "%A" it3

        return! inc 42
    }

    printfn "%A" (ask work (Imp()))

InterfaceState.fs


module InterfaceState
open FSharpx.State

type It =
    abstract Do1 : unit -> unit
    abstract Inc : int -> int

let do1 (it:It) =
    it.Do1 ()
    (), it

let inc i (it:It) =
    (it.Inc i), it

type Imp() =
    interface It with
        member x.Do1 () = printfn "Do1"
        member x.Inc i = i + 1

let test1 () =
    let work = state {
        do! do1
        return! inc 42
    }

    printfn "%A" (eval work (Imp()))

paket.dependencies

framework: net45
references: strict
source https://www.nuget.org/api/v2
nuget FSharpx.Extras

paket.references

FSharpx.Extras

Program.fs


module Main

[<EntryPoint>]
let main argv =
    //do StateQueue.test1()
    //do ReaderStack.test1()
    //do StringBuilder.test1()
    //InterfaceState.test1()
    InterfaceReader.test1()
    0

ReaderStack.fs


// http://codebetter.com/matthewpodwysocki/2010/01/07/much-ado-about-monads-reader-edition/

module ReaderStack
open FSharpx.Reader
open System.Threading
open System.Collections.Generic

let tryRunLock lock m =
    let lock = box lock
    let lockTaken = ref false
    Monitor.Enter (lock, lockTaken)

    if lockTaken.Value then
        try Some (m lock) // runReader m lock ~ m lock
        finally Monitor.Exit lock
    else
        None

let pulseAll = Monitor.PulseAll
let wait = fun o -> Monitor.Wait o |> ignore

let pop (stack:Stack<_>) = reader {
    while stack.Count = 0 do return! wait
    return stack.Pop() }

let push (stack:Stack<_>) x = reader {
    if stack.Count = 0 then return! pulseAll
    do stack.Push(x) }

// Our lock object
let lockObj = new obj()

let move s1 s2 =
    reader {
        let! x = pop s1
        do! push s2 x
        return x }
    |> tryRunLock lockObj

let test1() =
    let s1 = Stack<int> [1..3]
    let s2 = Stack<int> ()
    let moved = move s1 s2
    printfn "%A" s1
    printfn "%A" s2
    printfn "%A" moved

StateQueue.fs

module StateQueue
open FSharpx.State

let enqueue a lst = ((), lst @ [a])
let dequeue = function
    | hd::tl -> (hd, tl)
    | _ -> invalidOp ""

let test1 () =
    let workflow = state {
        //let! queue = getState
        do! enqueue 4
        let! hd = dequeue
        do! enqueue (hd * 3)
        return hd
    }

    printfn "%A" (workflow [3..6])
    printfn "%A" (eval workflow [3..6])
    printfn "%A" (exec workflow [3..6])

StringBuilder.fs

// http://www.fssnip.net/d5/title/A-Computation-Expression-wrapper-for-StringBuilder

module StringBuilder
open System

type StringBuilder = B of (Text.StringBuilder -> unit)

let build (B f) =
    let b = new Text.StringBuilder()
    do f b
    b.ToString ()

(*
    member __.Yield (o : obj) = B(fun b -> b.Append o |> ignore)
    - add object, sloppy

    member __.YieldFrom (txt : string seq) = B(fun b -> for t in txt do b.Append t |> ignore)
    - add seq of strings, sloppy 
*)
type StringBuilderM () =
    let (!) = function B f -> f
    member __.Yield (txt : string) = B (fun b -> b.Append txt |> ignore)
    member __.Yield (c : char) = B (fun b -> b.Append c |> ignore)
    member __.YieldFrom f = f
    member __.Combine (f, g) = B (fun b -> !f b; !g b)
    member __.Delay f = B (fun b -> !(f ()) b)
    member __.Zero () = B (fun _ -> ())
    member __.For (xs : 'a seq, f : 'a -> StringBuilder) =
        B (fun b ->
            let e = xs.GetEnumerator ()
            while e.MoveNext () do
                !(f e.Current) b
        )
    member __.While (p : unit -> bool, f : StringBuilder) =
        B (fun b -> while p () do !f b)

let string = new StringBuilderM ()

// example
let test1 () =
    let r =
        string {
            for x in [1] do
                yield sprintf "%d " x
            
            let mutable x = true
            while x do
                yield sprintf "%A " x
                x <- false
            
            yield "s1"
            yield ' '
            yield "s2"
            yield ' '
            yield! string {
                yield "nested"
            }
        }
    let r = r |> build

    printfn "%s" r