[Ramda] Basic Curry with Ramda
var _ = R; /*****************************************
C U R R Y I N G E X A M P L E
******************************************/ // We've got a nice multiply function.
// It takes two arguments. console.log( _.multiply(3, 4) ); // But it has been secretly curried already
// so we can feed it fewer arguments and it
// will return a new function.
//
// How about making a function to double a
// value? Done.
var double = _.multiply(2); console.log( double(13) ); /*****************************************
Y O U R T U R N
******************************************/ // _.split pulls a string apart around a
// given value
console.log( _.split('i', 'mississippi') ); // -- Challenge 1 ------------------------
// Make a function called "words" which
// returns a list of words in a string.
// Use only the split function and
// currying. console.log("Testing challenge 1..."); var words = _.split(' '); // change this
assertEqualArrays(
['one', 'two', 'three'],
words('one two three')
);
console.log("passed"); // -- Challenge 2 ------------------------
// Create a function to triple every
// number in a list using only
// _.multiply and _.map. console.log("Testing challenge 2..."); var tripleList = _.map(_.multiply(3));
assertEqualArrays([3,6,9], tripleList([1,2,3])); console.log("passed"); // -- Challenge 3 ------------------------
// Create a function to find the largest
// number in a list. You can use the
// greater(a,b) function which returns the
// greater of its two inputs. You can do
// this with currying and one of the list
// functions _.map, _.filter, or _.reduce. console.log("Testing challenge 3..."); var greater = function(a,b) {
return a > b ? a : b;
}; var max = _.reduce(greater, -Infinity);
assertEqual(9, max([1,-3483,9,7,2]));
assertEqual(-1, max([-21,-3483,-2,-1])); console.log("passed"); console.log("All tests pass.");
/******************************************
B A C K G R O U N D C O D E
*******************************************/ function assertEqualArrays(x,y) {
if(x.length !== y.length) throw("expected "+x+" to equal "+y);
for(var i in x) {
if(x[i] !== y[i]) {
throw("expected "+x+" to equal "+y);
}
}
}
function assertEqual(x,y){
if(x !== y) throw("expected "+x+" to equal "+y);
}
[Ramda] Basic Curry with Ramda的更多相关文章
- [Ramda] Handle Errors in Ramda Pipelines with tryCatch
Handling your logic with composable functions makes your code declarative, leading to code that's ea ...
- [Ramda] Curry and Uncurry Functions with Ramda
Most of the functions offered by the ramda library are curried by default. Functions you've created ...
- [Ramda] R.project -- Select a Subset of Properties from a Collection of Objects in Ramda
In this lesson we'll take an array of objects and map it to a new array where each object is a subse ...
- 从函数式编程到Ramda函数库(二)
Ramda 基本的数据结构都是原生 JavaScript 对象,我们常用的集合是 JavaScript 的数组.Ramda 还保留了许多其他原生 JavaScript 特性,例如,函数是具有属性的对象 ...
- [Javascript] Monads
Monads allow you to nest computations. They are a pointed functor that adds mjoin and chain function ...
- [Javascript] What is JavaScript Function Currying?
Currying is a core concept of functional programming and a useful tool for any developer's toolbelt. ...
- js函数式编程(二)-柯里化
这节开始讲的例子都使用简单的TS来写,尽量做到和es6差别不大,正文如下 我们在编程中必然需要用到一些变量存储数据,供今后其他地方调用.而函数式编程有一个要领就是最好不要依赖外部变量(当然允许通过参数 ...
- dWebpack编译速度优化实战
当你的应用的规模还很小时,你可能不会在乎Webpack的编译速度,无论使用3.X还是4.X版本,它都足够快,或者说至少没让你等得不耐烦.但随着业务的增多,嗖嗖嗖一下项目就有上百个组件了,也是件很简单的 ...
- 2019年11个javascript机器学习库
Credits: aijs.rocks 虽然python或r编程语言有一个相对容易的学习曲线,但是Web开发人员更喜欢在他们舒适的javascript区域内做事情.目前来看,node.js已经开始向每 ...
随机推荐
- Android 获取本机WIFI及3G网络IP
获取本机WIFIprivate String getLocalIpAddress() { WifiManager wifiManager = (WifiManager) getSystemServic ...
- Ui篇--layout_weight体验(实现按比例显示)
在android开发中LinearLayout很常用,LinearLayout的内控件的android:layout_weight在某些场景显得非常重要,比如我们需要按比例显示.android并没用提 ...
- 带宽计算-大B与小b的区别
原文来自:http://blog.sina.com.cn/s/blog_4b9c0e3601008yf9.html 在计算机网络.IDC机房中,其宽带速率的单位用bps(或b/s)表示:换算关系为:1 ...
- mybatis系列-08-动态sql
8.1 什么是动态sql mybatis核心 对sql语句进行灵活操作,通过表达式进行判断,对sql进行灵活拼接.组装. 8.2 需求 用户信息综合查询列表和用户信息查询列表总数这两个 ...
- SVM应用
我在项目中应用的SVM库是国立台湾大学林智仁教授开发的一套开源软件,主要有LIBSVM与LIBLINEAR两个,LIBSVM是对非线性数据进行分类,大家也比较熟悉,LIBLINEAR是对线性数据进行分 ...
- 内核源码分析之进程地址空间(基于3.16-rc4)
所谓进程的地址空间,指的就是进程的虚拟地址空间.当创建一个进程时,内核会为该进程分配一个线性的地址空间(虚拟地址空间),有了虚拟地址空间后,内核就可以通过页表将进程的物理地址地址空间映射到其虚拟地址空 ...
- 迁移web.py项目至git@osc的项目演示平台
1. 开启演示平台 选择WSGI,输入应用名称,即是演示网页的网址. 2. web.py代码迁移 将Python的site-packages目录下的web文件夹复制到代码目录下,与网页程序在同一个文件 ...
- 为Elasticsearch添加中文分词
Elasticsearch的中文分词很烂,所以我们需要安装ik.首先从github上下载项目,解压: cd /tmp wget https://github.com/medcl/elasticsear ...
- Oracle的回收站和闪回查询机制(二)
上一篇中讲诉了Oracle中一些闪回查询(Flashback Query),这是利用回滚段信息来恢复一个或一些表到以前的一个时间点(一个快照).要注意的是,Flashback Query仅仅是查询以前 ...
- HDU 5778 abs (枚举)
abs 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5778 Description Given a number x, ask positive ...