#1 let emptyList = []
#2 let oneItem = "one " :: []
#3 let twoItem = "one " :: "two " :: []

let shortHand = ["apples "; "pears"]

let twoLists = ["one, "; "two, "] @ ["buckle "; "my "; "shoe "]

let objList = [box 1; box 2.0; box "three"]

#1 let one = ["one "]
#2 let two = "two " :: one
#3 let three = "three " :: two
#4 let rightWayRound = List.rev three

#5 let main() =
printfn "%A" one
printfn "%A" two
printfn "%A" three
printfn "%A" rightWayRound

["one "]
["two "; "one "]
["three "; "two "; "one "]
["one "; "two "; "three "]

let rangeList = [1..99]

let dynamicList = [for x in 1..99 -> x*x]

for(int x=0;x<99 ; x++)
{
   myList.Add(x*x);
}

let listOfList = [[2; 3; 5]; [7; 11; 13]; [17; 19; 23; 29]]

let rec concatList l =
match l with
| head :: tail -> head @ (concatList tail)
| [] -> []

let primes = concatList listOfList

printfn "%A" primes

[2; 3; 5; 7; 11; 13; 17; 19; 23; 29]

 List.head [5; 4; 3]

List.tail [5; 4; 3]

List.map (fun x -> x*x) [1; 2; 3]

List.filter (fun x -> x % 3 = 0) [2; 3; 5; 7; 9]

seq { 0 .. 10 .. 100 }

seq { for i in 1 .. 10 do yield i * i }

seq { for i in 1 .. 10 -> i * i }

let isprime n =
    let rec check i =
        i > n/2 || (n % i <> 0 && check (i + 1))
    check 2

let aSequence = seq { for n in 1..100 do if isprime n then yield n }

let seqEmpty = Seq.empty

let seqOne = Seq.singleton 10

let seqFirst5MultiplesOf10 = Seq.init 5 (fun n -> n * 10)
Seq.iter (fun elem -> printf "%d " elem) seqFirst5MultiplesOf10

0 10 20 30 40

let seqFromArray2 = [| 1 .. 10 |] |> Seq.ofArray 

let seqFromArray1 = [| 1 .. 10 |] :> seq<int>

let containsNumber number seq1 = Seq.exists (fun elem -> elem = number) seq1
let seq0to3 = seq {0 .. 3}
printfn "For sequence %A, contains zero is %b" seq0to3 (containsNumber 0 seq0to3)

let isDivisibleBy number elem = elem % number = 0
let result = Seq.find (isDivisibleBy 5) [ 1 .. 100 ]
printfn "%d " result

let mySeq = seq { for i in 1 .. 10 -> i*i }
let printSeq seq1 = Seq.iter (printf "%A ") seq1; printfn "" 
let mySeqSkipWhileLessThan10 = Seq.skipWhile (fun elem -> elem < 10) mySeq
mySeqSkipWhileLessThan10 |> printSeq

16 25 36 49 64 81 100

let mySeq = seq { for i in 1 .. 10 -> i*i }
let truncatedSeq = Seq.truncate 5 mySeq
let takenSeq = Seq.take 5 mySeq

let printSeq seq1 = Seq.iter (printf "%A ") seq1; printfn "" 


#1 truncatedSeq |> printSeq
#3 takenSeq |> printSeq

1 4 9 16 25 //truncate
1 4 9 16 25 //take

// Tuple of two integers.
( 1, 2 ) 

// Triple of strings.
( "one", "two", "three" ) 

// Tuple of unknown types.
( a, b ) 

// Tuple that has mixed types.
( "one", 1, 2.0 ) 

// Tuple of integer expressions.
( a + 1, b + 1)

let print tuple1 =
   match tuple1 with
    | (a, b) -> printfn "Pair %A %A" a b

let (a, b) = (1, 2)

let c = fst (1, 2) // return 1
let d = snd (1, 2)// return 2

let third (_, _, c) = c

let divRem a b = 
   let x = a / b
   let y = a % b
   (x, y)

These are the customer-reported issues addressed in 15.7.3:

• VS2017 compiler creates broken debug build using Qt framework and generates 'Invalid address specified to RtlValidateHeap' error.
• Incorrect code generation for matrix multiplication.
• VS 2017 Update 7: Git History Codelens only showing entries for the past 6 months.
• UWP projects reference multiple NetStandard 2.0 dlls after 15.7.1 upgrade.
• Building C++ code in VS 15.7 with /std:c++17 breaks binary compatibility for std::_Ptr_move_cat.
• Visual Studio 15.7 stuck when opening XAML files.
• CMake configuration fails and generates message "C++ IntelliSense information may be out of date, generate the CMake cache to refresh".
• Unable to start second process for debugging.
• After update to Visual Studio 15.7.1, some test programs fail in start-up due to reading access violation.
• Missing compiler required member 'Microsoft.CSharp.RuntimeBinder.Binder.Convert'.
• Build fails after 15.7.0 update on older project using .NET 3.5 .
• Coloring, typing, tooltips and IntelliSense slow in F# in VS2017 editor.
• F# editing experience takes up to a minute for tooltips and dropdowns to display.
• Certain class member variable value are incorrectly read as zero.
• Attempt to open XAML file for the first time causes VS to sit with the "Opening the file ..." message for about 10 minutes before XAML file opens.
• Visual Studio slows down and freezes, creating work loss.
• The target "GetBuiltProjectOutputRecursive" does not exist in the project.
• Internal error with lambda C++17 after 15.7.1 update.
• UWP App is slow to return a stopped state in IDE.
• MSVC auto-vectorization produces incorrect code or incorrect results.
• Visual Studio closed debug a new instance project1, when a new debug new instance project2 has started.
• Latest update breaks "start without debugging" on multiple projects.
• UWP XAML is very very slow on open.
• XAML viewer freezes on 15.7.2 and 15.8.0 preview 1.1.
• Xamarin UI Test App project template missing.
• Xamarin project creation problem.
• Visual Studio crashes when creating new Mobile APP Xamarin.
• Unable to create Xamarin.Forms-Projects.
• Não consigo criar novos projetos Xamarin Forms - Can't create new projects Xamarin Forms.
• Blank project crash after update. 

// crate a surface
var info = new SKImageInfo(256, 256);
using var surface = SKSurface.Create(info);
// the the canvas and properties
var canvas = surface.Canvas;

// make sure the canvas is blank
canvas.Clear(SKColors.White);

// draw some text
using var typeface = SKTypeface.FromFamilyName("Tahoma");
using var paint = new SKPaint
    {
      Color = SKColors.Black,
      IsAntialias = true,
      Style = SKPaintStyle.Fill,
      TextAlign = SKTextAlign.Center,
      TextSize = 24,
      Typeface = typeface,
    };
var coord = new SKPoint(info.Width / 2, (info.Height + paint.TextSize) / 2);
canvas.DrawText("آزمایش", coord, paint);

// save the file
using var image = surface.Snapshot();
using var data = image.Encode(SKEncodedImageFormat.Png, 100);
using var stream = File.OpenWrite("farsi-text-1.png");
data.SaveTo(stream);

<ItemGroup>
   <PackageReference Include="SkiaSharp" Version="2.88.3" />
</ItemGroup>

<ItemGroup>
   <PackageReference Include="SkiaSharp" Version="2.88.3" />
   <PackageReference Include="SkiaSharp.HarfBuzz" Version="2.88.3" />
</ItemGroup>

// crate a surface
var info = new SKImageInfo(256, 256);
using var surface = SKSurface.Create(info);
// the the canvas and properties
var canvas = surface.Canvas;

// make sure the canvas is blank
canvas.Clear(SKColors.White);

// draw some text
using var typeface = SKTypeface.FromFamilyName("Tahoma");
using var shaper = new SKShaper(typeface);
using var paint = new SKPaint
  {
      Color = SKColors.Black,
      IsAntialias = true,
      Style = SKPaintStyle.Fill,
      TextAlign = SKTextAlign.Center,
      TextSize = 24,
      Typeface = typeface,
  };
var coord = new SKPoint(info.Width / 2, (info.Height + paint.TextSize) / 2);
canvas.DrawShapedText(shaper, "آزمایش", coord, paint);

// save the file
using var image = surface.Snapshot();
using var data = image.Encode(SKEncodedImageFormat.Png, 100);
using var stream = File.OpenWrite("farsi-text-2.png");
data.SaveTo(stream);

Top Issues Fixed in Visual Studio 2019 version 16.6.0

• When New Git experience feature flag is enabled, a message will appear in Team Explorer guiding users to the new Git tool window.
• Fix for intermittent UI delay while closing VS when WinForms .NET Core designer is in open state.
• Fixed issues creating projects using type providers, throwing missing method exception at runtime.
• Fixed project creation for .NET framework projects.
• New find in files experience respects options in Tools-Options-Find and Replace pane.
• Fixed a bug where Git repository does not change when closing a Folder and opening a Solution.
• Fixed bug when building iOS app using full debug symbols.
• Added back browing of Mac Distribution provisioning profiles and certificates from Windows.
• Fixed a bug causing Visual Studio 2019 to stop responding when working with Xamarin projects on certain scenarios.
• Added keyboard shortcut for "Copy with Headers" option in SQL Script Results Grid
• SSDT users will now be able to set and view sensitivity properties for all version above SQL Server 2008
• Improve Connection Properties dialog for accessibility users.
• Fixed occasional crashes when using Tested By Code Lens indicator.
• Ensure auto population of text in Find in files is as per legacy behavior.
• Ensure left arrow key behavior in find in files is correct.
• An issue blocking C++ users of the C++20 Ranges library from using algorithms. 

Security Advisory Notices

CVE-2019-1077 Visual Studio Extension Auto Update Vulnerability

An elevation of privilege vulnerability exists when the Visual Studio Extension auto-update process improperly performs certain file operations. An attacker who successfully exploited this vulnerability could delete files in arbitrary locations. To exploit this vulnerability, an attacker would require unprivileged access to a vulnerable system. The security update addresses the vulnerability by securing locations the Visual Studio Extension auto-update performs file operations in.

CVE-2019-1075 ASP.NET Core Spoofing Vulnerability

A spoofing vulnerability exists in ASP.NET Core that could lead to an open redirect. An attacker who successfully exploited the vulnerability could redirect a targeted user to a malicious website. To exploit the vulnerability, an attacker could send a link that has a specially crafted URL and convince the user to click the link.

The security update addresses the vulnerability by correcting how ASP.NET Core parses URLs. Details can be found in the .NET Core release notes.

CVE-2019-1113 WorkflowDesigner XOML deserialization allows code execution

A XOML file referencing certain types could cause random code to be executed when the XOML file is opened in Visual Studio. There is now a restriction on what types are allowed to be used in XOML files. If a XOML file containing one of the newly unauthorized types is opened, a message is displayed explaining that the type is unauthorized.

For further information, please refer to https://support.microsoft.com/en-us/help/4512190/remote-code-execution-vulnerability-if-types-are-specified-in-xoml.

These are the customer-reported issues addressed in 15.8.4:

• Constexpr function with explicit (void) parameter crashes MSVC 15.8.0 release.
• TypeScriptLspCodeActionProvider encountered an error and has been disabled.
• The 'Shared Web Components' package did not load correctly.
• Editing CSS with Browser Link enabled can crash Visual Studio.
• Service Fabric Deployment fails in 15.8.0.
• Incorrect error for constexpr pointer to members with VS2017 15.8.
• Constexpr doesn't support __declspec(dllimport) in VS2017 15.8.
• C++ VS 2017 Update 8 difference in member function pointer between C++14 and C++17 modes leads to crashes.
• TestExplorer locking up UI in latest build.
• [WebKit] "Already defined symbol" for static template member definition (regression).
• VS 15.8.0 Internal compiler error.
• Internal compiler error in constexpr function.
• Test Explorer Window remains blank with Express.
• Visual Studio 2017 fails to open on FIPS-enabled machine..
• VS2017 15.8 Internal Compiler Error 'msc1.cpp', line 1518 when evaluating simple constexpr function.
• Fatal error C1001 after update to VS 15.8.0.
• Migrating to VS2017 15.8: Internal compiler error when using constexpr functions as template parameters.
• Internal compiler error when compiling a template function with a constexpr in VC++ 15.8.0.
• Code generated by VC 15.8.1 compiler lead to crash.