#1 let mutable phrase = "Can it change? "

#2 printfn "%s" phrase

#3 phrase <- "yes, it can."

#4 printfn "%s" phrase

Can it change?  
yes, it can.

#1 let mutable phrase = "Can it change?  "

#3 phrase <- 1

Prog.fs(9,10): error: FS0001: This expression has type
int
but is here used with type
string

let redefineX() =
let x = "One"
printfn "Redefining:\r\nx = %s" x
if true then
   let x = "Two"
printfn "x = %s" x
printfn "x = %s" x

Redefining:
x = One
x = Two
x = One

let mutableX() =
let mutable x = "One"
printfn "Mutating:\r\nx = %s" x
if true then
   x <- "Two"
printfn "x = %s" x
printfn "x = %s" x

Mutating:
x = One
x = Two
x = Two

let refVar = ref 6

refVar := 50



printfn "%d" !refVar

let xRef : int ref = ref 10

printfn "%d" (xRef.Value)
printfn "%d" (xRef.contents)

xRef.Value <- 11
printfn "%d" (xRef.Value)
xRef.contents <- 12
printfn "%d" (xRef.contents)

10
10
11
12 

let keepIfPositive (a : int) = if a > 0 then Some(a) else None

let exists (x : int option) = 
    match x with
    | Some(x) -> true
    | None -> false

let rec tryFindMatch pred list =
    match list with
    | head :: tail -> if pred(head)
                        then Some(head)
                        else tryFindMatch pred tail
    | [] -> None

let result1 = tryFindMatch (fun elem -> elem = 100) [ 200; 100; 50; 25 ] //برابر با 100 است

let result2 = tryFindMatch (fun elem -> elem = 26) [ 200; 100; 50; 25 ]// برابر با None است

open System.IO
let openFile filename =
    try 
        let file = File.Open (filename, FileMode.Create)
        Some(file)
    with
        | ex -> eprintf "An exception occurred with message %s" ex.Message
                None

type enum-name =
   | value1 = integer-literal1
   | value2 = integer-literal2
   ...

type Color =
   | Red = 0
   | Green = 1
   | Blue = 2

let col1 : Color = Color.Red

type uColor =
   | Red = 0u
   | Green = 1u
   | Blue = 2u
let col3 = Microsoft.FSharp.Core.LanguagePrimitives.EnumOfValue<uint32, uColor>(2u)

using(var writer = new StreamWriter(filePath))
{
   
}

let writeToFile fileName =
    use sw = new System.IO.StreamWriter(fileName : string)
    sw.Write("Hello ")

[<Measure>] type unit-name [ = measure ]

[<Measure>] type cm

[<Measure>] type ml = cm^3

let value = 1.0<cm>

[<Measure>] type g                 تعریف واحد گرم
[<Measure>] type kg               تعریف واحد کیلوگرم
let gramsPerKilogram : float<g kg^-1> = 1000.0<g/kg>    تعریف تابع تبدیل

[<Measure>] type degC // دما بر حسب سلسیوس
[<Measure>] type degF // دما بر حسب فارنهایت

let convertCtoF ( temp : float<degC> ) = 9.0<degF> / 5.0<degC> * temp + 32.0<degF> // تابع تبدیل سلسیوس به فارنهایت
let convertFtoC ( temp: float<degF> ) = 5.0<degC> / 9.0<degF> * ( temp - 32.0<degF>) // تابع تبدیل فارنهایت به سلسیوس

let degreesFahrenheit temp = temp * 1.0<degF> // درجه به فارنهایت
let degreesCelsius temp = temp * 1.0<degC> // درجه به سلسیوس

printfn "Enter a temperature in degrees Fahrenheit." 
let input = System.Console.ReadLine()
let mutable floatValue = 0.
if System.Double.TryParse(input, &floatValue)// اگر ورودی عدد بود
   then 
      printfn "That temperature in Celsius is %8.2f degrees C." ((convertFtoC (degreesFahrenheit floatValue))/(1.0<degC>))
   else
      printfn "Error parsing input."

Enter a temperature in degrees Fahrenheit.
90
That temperature in degrees Celsius is    32.22.

1.  Get/GetAsync(with data retriever)
2.  Get/GetAsync(without data retriever)
3.  Set/SetAsync
4.  Remove/RemoveAsync
5.  ~~Refresh/RefreshAsync (was removed)~~
6.  RemoveByPrefix/RemoveByPrefixAsync
7.  SetAll/SetAllAsync
8.  GetAll/GetAllAsync
9.  GetByPrefix/GetByPrefixAsync
10.  RemoveAll/RemoveAllAsync
11.  GetCount
12.  Flush/FlushAsync
13.  TrySet/TrySetAsync
14.  GetExpiration/GetExpirationAsync

1. In-Memory
2. Memcached
3. Redis(Based on StackExchange.Redis)
4. Redis(Based on csredis)
5. SQLite
6. Hybrid
7. Disk
8. LiteDb

1. BinaryFormatter
2. MessagePack
3. Newtonsoft.Json
4. Protobuf
5. System.Text.Json

• MessagePack
• Newtonsoft.Json
• Protobuf
• System.Text.Json

• دوره "معرفی SignalR و ارتباطات بلادرنگ"
  
• نگاهی به اجزای تعاملی Twitter Bootstrap 
  

{
    "userIsAuthorizedForCourseTranscripts": false,
    "modules": [
        {
            "title": "Course Overview",
            "clips": [
                {
                    "title": "Course Overview",
                    "playerParameters": "author=scott-allen&name=aspdotnet-core-1-0-fundamentals-m0&mode=live&clip=0&course=aspdotnet-core-1-0-fundamentals",
                    "transcripts": [ ]
                }
            ]
        },
        {
            "title": "Building Your First ASP.NET Core Application",
            "clips": [
                {
                    "title": "Introduction",
                    "playerParameters": "author=scott-allen&name=aspdotnet-core-1-0-fundamentals-m1&mode=live&clip=0&course=aspdotnet-core-1-0-fundamentals",
                    "transcripts": [
                        {
                            "displayTime": 0.0,
                            "text": "Hi! This is Scott, and this course will help you build your first application with ASP.NET Core."
                        },
                        {
                            "displayTime": 7.0,
                            "text": "In this course, we'll be using Visual Studio and the new ASP.NET Framework to build a web application that"
                        }
                    ]
                }
            ]
        }
    ]
}

public class PluralsightCourse
{
    public bool UserIsAuthorizedForCourseTranscripts { get; set; }
    public PluralsightCourseItems[] Modules { get; set; }
}
public class PluralsightCourseItems
{
    public string Title { get; set; }
    public PluralsightCourseClip[] Clips { get; set; }
}
public class PluralsightCourseClip
{
    public string Title { get; set; }
    public string PlayerParameters { get; set; }
    public PluralsightCourseClipTranscript[] Transcripts { get; set; }
}
public class PluralsightCourseClipTranscript
{
    public float DisplayTime { get; set; }
    public string Text { get; set; }
}

public static PluralsightCourse ProcessJsonFile(string jsonData)
{
    return JsonConvert.DeserializeObject<PluralsightCourse>(jsonData);
}

 public static class  MyAttributes
    {
        [Obsolete]
        public static void MyMethod1()
        {

        }

        public static void MyMetho2()
        {

        }
    }

public  class  MyMaxLength:Attribute
    {
   
    }

[MyMaxLength]
    public class GetCustomProperties
    {
//...
     }

    public  class  MyMaxLength:Attribute
    {
        private int max;
        public string ErrorText = "";

        public MyMaxLength(int max)
        {
            this.max = max;
            ErrorText = string.Format("max Length is {0} chars", max);
        }
    }

 [MyMaxLength(30)]
    public class GetCustomProperties
    {
//...
     }

//or 
 [MyMaxLength(30,ErrorText = "شما اجازه ندارید بیش از 30 کاراکتر وارد نمایید")]
    public class GetCustomProperties
    {
//...
     }

    [System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Struct)]
    public  class  MyMaxLength:Attribute
    {
        private int max;
        public string ErrorText = "";

        public MyMaxLength(int max)
        {
            this.max = max;
            ErrorText = string.Format("max Length is {0} chars", max);
        }
    }

[AttributeUsage(AttributeTargets.Property)]

  public class User
    {
        [MyMaxLength(30, ErrorText = "شما اجازه ندارید بیش از 30 کاراکتر وارد نمایید")]
        public string Name { get; set; }
}

 [AttributeUsage(AttributeTargets.Property,AllowMultiple = true)]
    public  class  MyMaxLength:Attribute
    {
        //....
     }

[MyMaxLength(40, ErrorText = "شما اجازه ندارید بیش از 40 کاراکتر وارد نمایید")]
        [MyMaxLength(50, ErrorText = "شما اجازه ندارید بیش از 50 کاراکتر وارد نمایید")]
        [MyMaxLength(30, ErrorText = "شما اجازه ندارید بیش از 30 کاراکتر وارد نمایید")]
        public string Name { get; set; }

public class MyAttribute : Attribute
{
    //...
}

[AttributeUsage(AttributeTargets.Method, Inherited = false)]
public class YourAttribute : Attribute
{
    //...
}

public class MyClass
{
    [MyAttribute]
    [YourAttribute]
    public virtual void MyMethod()
    {
        //...
    }
}

public class YourClass : MyClass
{
    public override void MyMethod()
    {
        //...
    }

}

   Type type = typeof (User);

                foreach (PropertyInfo property in type.GetProperties())
                {
                    foreach (Attribute attribute in property.GetCustomAttributes(true))
                    {
                        MyMaxLength max = attribute as MyMaxLength;
                        if (max != null)
                        {
                            string Max = max.ErrorText;
                            //انجام عملیات
                        }
                    }
                }

[MyMaxLength(30, typeof(User))]

اما در مدل EAV، خواص داینامیک را به درون جدول دومی منتقل خواهیم کرد:

create table EmployeeEav
(
   Id int auto_increment
   primary key
);

create table EmployeeAttributes
(
  Id int auto_increment
  primary key,
  EmployeeId int not null,
  AttributeName text null,
  AttributeValue text null,
  constraint FK_EmployeeAttributes_EmployeeEav_EmployeeId
  foreign key (EmployeeId) references EmployeeEav (Id)
  on delete cascade
);

create index IX_EmployeeAttributes_EmployeeId
on EmployeeAttributes (EmployeeId);

تعریف جداول فوق نیز در Entity Framework به اینصورت خواهند بود:

public class EmployeeEav
{
    public int Id { get; set; }
    public virtual ICollection<EmployeeAttribute> Attributes { get; set; }
}

public class EmployeeAttribute
{
    public int Id { get; set; }
    public virtual EmployeeEav Employee { get; set; }
    public int EmployeeId { get; set; }
    public string AttributeName { get; set; }
    public string AttributeValue { get; set; }
}

public class MyDbContext : DbContext
{

    public DbSet<EmployeeEav> EmployeeEav { get; set; }
    public DbSet<EmployeeAttribute> EmployeeAttributes { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
    {
        options.UseMySQL(_configuration.GetConnectionString("DataConnection"));
    }
}

SELECT `e`.`Id`, `e`.`DateOfBirth`, `e`.`FirstName`, `e`.`LastName`
FROM `Employees` AS `e`
WHERE `e`.`DateOfBirth` > @__endDate_0

public class Driver
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string NationalCode { get; set; }
        public string CellPhone { get; set; }
        public string LicenseNumber { get; set; }
        public bool IsDriverAssistance { get; set; }

        [InverseProperty("Driver")]
        public virtual ICollection<Transference> Transferences { get; set; }
        [InverseProperty("DriverAssistance")]
        public virtual ICollection<Transference> TransferencesForAssistance { get; set; }
        [InverseProperty("Driver")]
        public virtual ICollection<Tanker> Tankers { get; set; }
        [InverseProperty("DriverAssistance")]
        public virtual ICollection<Tanker> TankersForAssistance { get; set; }

    }

 public class Transference
    {
        public string Id { get; set; }
        public DateTime Date { get; set; }
        public Int16 Lytrazh { get; set; }
        public bool IsEMS { get; set; }
        public DateTime LoadingDate { get; set; }
        public DateTime DeliveryDate { get; set; }
        [InverseProperty("Transferences")]
        public virtual Driver Driver { get; set; }
        [InverseProperty("TransferencesForAssistance")]
        public virtual Driver DriverAssistance { get; set; }
        public virtual TypeOfTanker TypesOfTanker { get; set; }
        public virtual Tanker Tanker { get; set; }
        public virtual Consumer Consumer { get; set; }

    }

 public class TransferenceConfig : EntityTypeConfiguration<Transference>
    {
        public TransferenceConfig()
        {
            // one-to-many
            this.HasRequired(x => x.Consumer)
                .WithMany(x => x.Transferences);

                // one-to-many
            this.HasRequired(x => x.TypesOfTanker)
                .WithMany(x => x.Transferences);

            // one-to-many
            this.HasRequired(x => x.Tanker)
                .WithMany(x => x.Transferences);

            // one-to-many
            this.HasRequired(x => x.Driver)
                .WithMany(x => x.Transferences);

            // one-to-many
            this.HasRequired(x => x.DriverAssistance)
                .WithMany(x => x.Transferences);

        }
    }

public class AsynchOperation : IAsyncResult
{
    private bool _completed;
    private Object _state;
    private AsyncCallback _callback;
    private HttpContext _context;

    bool IAsyncResult.IsCompleted { get { return _completed; } }
    WaitHandle IAsyncResult.AsyncWaitHandle { get { return null; } }
    Object IAsyncResult.AsyncState { get { return _state; } }
    bool IAsyncResult.CompletedSynchronously { get { return false; } }
}