第一章 why

第一节 shifting paradigms

一个好主意的出现，和这个好主意被广泛接受，这两件事之间通常有很长的时间间隔。
这个时间间隔的长短未必和这个主意多牛逼多神奇有关，而是有固定的发展曲线。
Often, good ideas await foundation technologies to catch up. In its early years, Java was regularly considered too slow and expansive in memory usage for high-performance applications, but shifts in the hardware market made it an attractive choice. Functional programming follows the same conceptual trajectory as object orientation: developed in academia over the last few decades, it has slowly crept into all modern programming languages.


学习一种新的语言是简单的，如果你仅仅是学习如何用新的语法来呈现你已知的概念。
学习一种新的语言是困难的，如果你想要掌握一种新的范式，并用新的思考方式来解决问题。
The problem with a completely new programming paradigm isn’t learning a new language. After all, everyone reading this has learned numerous computer languages — language syntax is merely details. The tricky part is learning to think in a different way.

第三节 ceding control to the language/runtime

把更多的控制权交给语言或者是运行时，这样程序员才能在更高的抽象层次上解决问题。
Java eased our interaction with memory management; functional programming languages allow us to replace other core building blocks with higher-order abstractions.

第四节 concision 简洁
OO makes code understandable by encapsulating moving parts. FP makes code understandable by minimizing moving parts. 
— Michael Feathers
encapsulation, scoping, visibility, and other mechanisms exist to exert fine-grained control over who can see and change state. More complications pile up when you deal with state plus threading. These mechanisms are what Feathers referred to as “moving parts.”
In the OOP world, developers are encouraged to create unique data structures, with specific operations attached in the form of methods.
Encapsulation at the function level allows reuse at a more granular, fundamental level than building new class structures for every problem.
Functional programmers prefer a few core data structures, building optimized machinery to understand them. Object-oriented programmers tend to create new data structures and attendant operations constantly — building new classes and messages between them is the predominant object oriented paradigm. Encapsulating all data structures within classes discourages reuse at the method level, preferring larger framework-style reuse. Functional programming constructs make it easier to reuse code at a more atomic level.

https://www.youtube.com/watch?v=7aYS9PcAITQ

http://www.defmacro.org/ramblings/fp.html

http://www.infoq.com/presentations/Simple-Made-Easy

http://steve-yegge.blogspot.in/2006/03/execution-in-kingdom-of-nouns.html