habib-sadullaev

#r "nuget: FSharp.Interop.Dynamic"

open System
open System.Collections
open System.Linq.Expressions
open System.Linq
open FSharp.Interop.Dynamic

// query.Select(selector)
let select (selector: LambdaExpression) (query: IQueryable) : IQueryable =

habib-sadullaev

#r "nuget:AWSSDK.SecurityToken"

open Amazon
open Amazon.Runtime.CredentialManagement
open Amazon.SecurityToken
open Amazon.SecurityToken.Model

let awsCredentials profile =
    let chain = CredentialProfileStoreChain()
    match chain.TryGetAWSCredentials profile with

habib-sadullaev

using System;
using System.Text.Json;

var value = new { name = default(string)! };

//method #1
value = (dynamic)JsonSerializer.Deserialize("""{ "name": "xyz" }""", value.GetType())!;
Console.WriteLine(value);

//method #1

habib-sadullaev

using System;
using System.Linq;
using System.Linq.Expressions;

static class _ 
{
    static void Deconstruct(this BinaryExpression x,
                            out ExpressionType type, 
                            out Expression left, 
                            out Expression right)

habib-sadullaev

type IRef = 
    abstract member Ref: unit -> byref<int>

type C() =
    let mutable num = 10
    member _.Get() = num
    member _.Ref() = &num 

    interface IRef with
        member this.Ref() = &this.Ref() 

habib-sadullaev

open System.Numerics

module NumericLiteralG =
    let inline FromZero () : #INumber<'a> = 'a.Zero 
    let inline FromOne () : #INumber<'a> = 'a.One
    let inline FromInt32 (number: int) : #INumber<'a> = 'a.CreateChecked(number)

let (*) x y : #IMultiplyOperators<'a, 'a, 'a>  = 'a.op_Multiply(x, y) 
let (/) x y : #IDivisionOperators<'a, 'a, 'a> = 'a.op_Division(x, y) 

habib-sadullaev

### Nullable Reference Types

https://devblogs.microsoft.com/dotnet/nullable-reference-types-in-csharp/

https://learn.microsoft.com/en-us/ef/core/miscellaneous/nullable-reference-types#non-nullable-properties-and-initialization

The purpose of nullable warnings is to minimize the chance that your application throws a `System.NullReferenceException` when run.

To enable Nullable Reference Types for all code in a project, you can add the following to its `.csproj` file:

habib-sadullaev

using System.Diagnostics.CodeAnalysis;
using System;

static Result<Foo, Err> GetResult(bool isErr)
    => isErr ? Result.Ok(new Foo()) : Result.Error(new Err());

Console.WriteLine(GetResult(true) switch
{
    { Success: true, Value: var value } => value,
    { Success: false, Error: var error } => error,

habib-sadullaev

namespace Data.Model.Entities
{
    using System;
    using System.Data.Entity.Core.Metadata.Edm;
    using System.Data.Entity.Infrastructure;
    using System.Data.Entity.ModelConfiguration.Conventions;
    using System.Linq;
    using System.Reflection;

    public class CommentSplittingFixer : IStoreModelConvention<EdmModel>

habib-sadullaev

type Tuple = Tuple with
    static member inline TupleMap (Tuple, (a, b)) = fun f -> (f a, f b)
    static member inline TupleMap (Tuple, (a, b, c)) = fun f -> (f a, f b, f c)
    static member inline TupleMap (Tuple, (a, b, c, d)) = fun f -> (f a, f b, f c, f d)

let inline mapTuple f x =
    let inline map (a: ^a) (b : ^b) = ((^a or ^b) : (static member TupleMap : ^a * ^b -> ^t) (a, b))
    map Tuple x f

mapTuple (fun x -> x * x + 1) (1, 2)