[Ramda] Getter and Setter in Ramda & lens

转载于 2016-10-10 21:12:00 发布 · 71 阅读

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原文链接：http://www.cnblogs.com/Answer1215/p/5947316.html

本文介绍了如何使用Ramda.js中的Getter和Setter方法操作对象属性，并展示了通过Lens进行更复杂的读写操作。

Getter on Object:

1. prop:

R.prop('x', {x: 100}); //=> 100
R.prop('x', {}); //=> undefined

2. props:

R.props(['x', 'y'], {x: 1, y: 2}); //=> [1, 2]
R.props(['c', 'a', 'b'], {b: 2, a: 1}); //=> [undefined, 1, 2]

Setter ob Object:

R.assoc('c', 3, {a: 1, b: 2}); //=> {a: 1, b: 2, c: 3}

Another way to use Lens:

var xLens = R.lens(R.prop('x'), R.assoc('x'));

R.view(xLens, {x: 1, y: 2});            //=> 1
R.set(xLens, 4, {x: 1, y: 2});          //=> {x: 4, y: 2}

转载于:https://www.cnblogs.com/Answer1215/p/5947316.html