![Lists, Arrays, Sequences
• Lists: ordered, immutable collections of elements of the same
type
• [ ] // empty list
• [1; 2; 3]
• [ 1 .. 10 ]
• Array: fixed-size, mutable collections of elements of the same
type
• [| |] // empty array
• 其餘的寫法跟 List 一樣
• Sequences: a logical series of elements, all of the same type
• Seq.empty // empty sequence
• seq { 1.. 10 }](https://image.slidesharecdn.com/dotnetconf2021-fsharp-211219021819/85/Dotnet-Conf-2021-F-and-Safe-Stack-13-320.jpg)
Dotnet Conf 2021 - F# and Safe Stack
- 1. 探索 .NET 新世界
- 2. F# & SAFE Stack 函數式開發典範 Kevin Yang
- 3. F# 基本介紹
- 4. 什麼是 F# • An open-source language that makes it easy to write succinct, robust, and performant code. • Many features • Lightweight syntax • Immutable by default • Type inference and automatic generalization • First-class functions • Powerful data types • Pattern matching • Async programming
- 5. 執行環境 • 安裝 .NET SDK 6 （支援 F# 6，有很多新功能) • 編輯器選擇 • Visual Studio • Visual Studio Code with【 Ionide-fsharp 】extension
- 6. Something about Function • Simple Rule • One input and return one output • Pure function • Given the same input, it will always return the same output. Produces no side effects. • Benefits • easy to test • cacheable • parallelizable.
- 7. F# 語法介紹
- 8. Functions and modules • Functions 是 F# 最基本元素 • 可用 Modules 來做分類管理 • 使用 open 來打開 module • 使用 let 宣告 function • 使用 let 綁定值到變數上 (Immutable) • 使用 mutable 設定變數為 mutable • 使用 <- 來改變值
- 9. Pipelines • he pipe operator |> is used extensively when processing data in F#.
- 10. Curried Functions • Currying is a process that transforms a function that has more than one parameter into a series of embedded functions, each of which has a single parameter.
- 11. 型別 • 基礎型別 • string • double quote • string literal with @ or triple quote • concatenation with + • %s print a string value (type-safe) • substrings use the indexer notation • integer • %d print an integer value (type-safe) • float • %f print a float value (type-safe) • Boolean • %b print a Boolean value (type-safe)
- 12. Tuples • grouping of unnamed but ordered values let tuple1 = (1, 2, 3) let swapElems (a, b) = (b, a)
- 13. Lists, Arrays, Sequences • Lists: ordered, immutable collections of elements of the same type • [ ] // empty list • [1; 2; 3] • [ 1 .. 10 ] • Array: fixed-size, mutable collections of elements of the same type • [| |] // empty array • 其餘的寫法跟 List 一樣 • Sequences: a logical series of elements, all of the same type • Seq.empty // empty sequence • seq { 1.. 10 }
- 14. Record • an aggregate of named values, with optional members (such as methods) type ContactCard = { Name : string Phone : string Verified : bool } let contact1 = { Name = "Alf" Phone = "(206) 555-0157" Verified = false } let contact2 = { contact1 with Phone = "(206) 555-0112" Verified = true }
- 15. Discriminated Unions • values that could be a number of named forms or cases. type Suit = | Hearts | Clubs | Diamonds | Spades type Rank = /// Represents the rank of cards 2 .. 10 | Value of int | Ace | King | Queen | Jack
- 16. Pattern Matching • the F# feature that enables correctness for operating on F# types.
- 18. SAFE Stack
- 19. 什麼是 SAFE • An end-to-end, functional-first stack for cloud-ready web development that emphasizes type-safe programming • .NET Core ready
- 20. 什麼是 SAFE • Saturn + Giraffe for back-end services in F# • Azure (Host) <= 為了拼出 SAFE 硬加上去的 • Fable for running F# in the web browser • Elmish for client-side user interfaces
- 21. 使用 SAFE • 安裝 SAFE project template (One time effort) • • 使用 safe project template dotnet new –I SAFE.Template dotnet new SAFE
- 22. Demo TODO App with SAFE Stack
- 23. Take away • F# is fun, you should try it sometime. • FP 不難，只是他用另外一個角度思考問題罷了
- 24. References • SAFE Documentation • https://safe-stack.github.io/docs/template-overview/ • SAFE Demo Code • https://github.com/chgc/FSharp-and-safe-demoCode- dotnetConf2021 • F# • https://fsharp.org/ • Functional BDD Demo Code • https://github.com/chgc/example-functional-bdd-dotnetConf2021
- 25. Kevin Yang • Blog https://blog.kevinyang.net/ • FB Page https://www.facebook.com/CKNotepad
Editor's Notes
- #5: F # 是一種開放原始碼、跨平臺、互通的程式設計語言，可用於撰寫簡潔、穩固且高效能的程式碼。 您的焦點會保持在您的問題領域，而不是程式設計的詳細資料。 輕量語法 預設為不可變 型別推斷和自動一般化 一級函式 強大的資料類型 模式比對 非同步程式設計