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ER

---
title: Order example
---
erDiagram
    CUSTOMER ||--o{ ORDER : places
    ORDER ||--|{ LINE-ITEM : contains
 CUSTOMER }|..|{ DELIVERY-ADDRESS : uses

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public class UrlServiceResolverHandler : DelegatingHandler
{
    readonly ILogger<UrlServiceResolverHandler> logger;

    public UrlServiceResolverHandler(ILogger<UrlServiceResolverHandler> logger)
    {
        this.logger = logger;
        InnerHandler = new HttpClientHandler();
    }

lucasteles

using System.IO.Compression;
using System.Text;

interface ICompressor
{
    public const string Header = "[z]";
    Task<string> Compress(string text);
    Task<string> Decompress(string text);
}

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using System.Globalization;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Heptapod.Models.Values;

[JsonConverter(typeof(UtcJsonConverter))]
public readonly struct DateUtc
{
    public DateUtc(DateTime dateTime) => DateTime = dateTime.ToUniversalTime();

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public abstract record Result<TOk, TError>
{
    public sealed record Ok(TOk Value) : Result<TOk, TError>
    {
        public override TOk Default(TOk defaultValueIfError) => Value;
        public override T Match<T>(Func<TOk, T> ok, Func<TError, T> error) => ok(Value);
        public override Result<TMap, TError> Select<TMap>(Func<TOk, TMap> map) => map(Value);
        public override Result<TMap, TError> Bind<TMap>(Func<TOk, Result<TMap, TError>> bind) => bind(Value);
        public override bool IsError => false;
    }

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using System.ComponentModel;

public static string GetDescription<T>(this T option) where T : Enum => option
        .GetType().GetMember(option.ToString())
        .SelectMany(p => p.GetCustomAttributes(typeof(DescriptionAttribute), true))
        .FirstOrDefault() is DescriptionAttribute attr
            ? attr.Description
            : option.ToString();

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[<AutoOpen>]
module MinimalExtensions

open System
open Microsoft.AspNetCore.Builder
open Microsoft.AspNetCore.Routing

type IEndpointRouteBuilder with
    static member ParseArityOneFuncToDelegate(func: Func<'a, 'b>) : Delegate =
        match box func with

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type TupleToObject<T extends any[]> = { [K in keyof T as Exclude<K, keyof any[]>]: T[K] }
type MapTuples<T extends any[], N extends Record<keyof TupleToObject<T>, PropertyKey>> = 
    { [K in keyof TupleToObject<T> as N[K]]: T[K] }
type IsNever<T> = [T] extends [never] ? true : false
type Numbers = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
type IncMap = MapTuples<Tail<Numbers>, Numbers>
type Inc<T extends number> = T extends keyof IncMap ? IncMap[T] : never
export type Reverse<T extends any[], R extends any[] = []> = { 
    return: R
    next: Reverse<Tail<T>, Cons<Head<T>, R>>

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export type AllChars = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
export type ValidChar = AllChars[number]

type TupleToObject<T extends any[]> = { [K in keyof T as Exclude<K, keyof any[]>]: T[K] }
type MapTuples<
  T extends any[],
  N extends Record<keyof TupleToObject<T>, PropertyKey>> = 
    { [K in keyof TupleToObject<T> as N[K]]: T[K] }
   
type IncMap = MapTuples<Tail<AllChars>, AllChars>

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type IncMap = { 0: 1; 1: 2; 2: 3; 3: 4; 4: 5; 5: 6; 6: 7; 7: 8; 8: 9; 9: 10;
                10:11;11:12;12:13;13:14;14:15;15:16;16:17;17:18;18:19;19:20;
                20:21;21:22;22:23;23:24;24:25;25:26 }
type Inc<T extends number> = T extends keyof IncMap ? IncMap[T] : never
type Head<T extends any[]> = T extends [any, ...any[]] ? T['0'] : never
type Tail<T extends any[]> = ((...t: T) => never) extends (h: any, ...rest: infer R) => never ? R : never
type Cons<V,T extends any[]> = ((h: V, ...t: T) => void) extends (...t: infer R) => void ? R : never
type IsEqual<A, B> = A extends B ? (B extends A ? true : false) : false
type IsNever<T> = [T] extends [never] ? true : false