Functional Programming

Is it useful...?

You are a beginner again...

No loops;
No mutating data;
No impure functions.

Algebraic structures;
Type classes;
Algebraic data types.

Difficult Concepts...

I tried...

• Haskell books...
• Many articles...
• Elm...

How to program?
There are mainly 2 mindsets.

• Start from the Von Neumann architecture and add abstraction.
• Start from mathematics and remove abstraction.

• My advice: think between spectrum...

Pros./cons. of the abstraction?

Performance? Details management?

Math at school ...? Programming at work ...?

1. =

2. function

x = 5;

x = x + 1;

a = obj.func_one(1);

b = obj.func_one(1);

a = func_one(1);

b = func_one(1);

範疇論（英語：Category theory）是數學的一門學科，以抽象的方法處理數學概念，將這些概念形式化成一組組的「物件」及「態射」。數學中許多重要的領域可以形式化為範疇。使用範疇論可以令這些領域中許多難理解、難捉摸的數學結論更容易敘述證明。

研究範疇就是試圖以「公理化」的方法抓住在各種相關連的「數學結構」中的共同特性，並以結構間的「結構保持函數」將這些結構相關起來。因此，對範疇論系統化的研究將允許任何一個此類數學結構的普遍結論由範疇的公理中證出。

See production app & some Elm code ...

Think between Spectrum

Let's have a look at ...

• https://github.com/jfmengels/eslint-plugin-fp
• https://github.com/jonaskello/eslint-plugin-functional

Turing Machine & Lambda calculus

Story behind JavaScript...

Thanks for listening.