Suparnar Taina

Suparnar Taina

1594459389

Haskell-like Composition in JavaScript

Functional composition applies one function to the results of another: const f = x => g(h(x)). In the example functions g and h are composed. In Haskell notation it can be rewritten as follows: f = g . h, where . is an infix compose function.

It is ok to have just one nested pair of parentheses in your code, but when you need to compose multiple functions it is better to use a higher-order function like Ramda’s compose. I prefer to write it line by line with trailing comma:

import R from 'ramda';

const f = R.compose(
  g,
  h,
  m,
  n,
  p,
)

This code is equivalent to the following less readable and modifiable code:

const f = x => g(h(m(n(p(x)))))

What if we can compose functions in JS like in Haskell:

const f = g . h . m . n . p;

It looks concise, easy to read, fast to write. The best part is that it’s possible in JS.

#functional-programming #haskell #js #javascript

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Haskell-like Composition in JavaScript
Abigale  Yundt

Abigale Yundt

1599661800

Forms of Composition in JavaScript and React

One of the core ideas in functional programming is composition: building larger things from smaller things. The canonical example of this idea should be familiar with legos.

Multiple legos can be joined and yield another lego that can continue to be built on and attached to others. In functional programming, the basic unit for composition is functions and larger functions are built by connecting and combining smaller ones.

When asked how to handle a particular scenario, edge case, or requirement, a functional programmer will nearly always answer: ‘with a function’.

Object-oriented concepts like factories, strategy mangers, or polymorphism don’t have an equivalent in the functional paradigm. Functional programming has its own key concepts, composition is one.

A (quick) Aside

One distinction between functional and object oriented programming is best seen in the difference between

circle.area()andarea(circle). In the first version - a more object oriented style -areais a method that exists on theCircleclass and can only be called onCircleinstances. In the second,areais a function that accepts an object. Unlike the object oriented version, it can act on any object that conforms to the type expected byarea.

This illustrates a core difference between the two paradigms. In an object oriented world, data and functionality are coupled -

areais a function on instances ofCircleobjects limited to objects created by that class. In functional programming, data and functionality are decoupled -areais a function that can act on any object that has the required properties.

While object oriented patterns have interfaces, inheritance and other mechanisms for sharing behavior like calculating the area of various shapes, it can often feel like you’re standing in an abandoned abstract factory churning out reverse proxies* 🙃

*I’ve never written an abstract factory and this is just a cheeky line to maintain engagement. Like all things, OO is another tool to leverage when needed.

Forms of Composition

Functions are not the sole unit of composition and the principle extends beyond the domain of functional programming. ReactJS uses components as a unit of composition. Hooks too like

useStateare another unit. If you’re really focusing, you may notice that hooks are just regular functions which is why they are great for composition.

Its possible to build larger components from smaller components, and write custom hooks that extend the capability of existing hooks.

Composition relies on recursion to build larger abstractions from smaller abstractions but with each abstraction layer as the same type as all the others. Once a compositional unit like functions or components exist, you immediately get a compositional model that allows for building high level abstractions very quickly for free. Each layer of abstraction is fundamentally the same type of thing as all the other layers.

An Example of (Functional) Composition

Let’s begin with three functions.

const toUpperCase = str => str.toUpperCase();
const appendExclamationPoints = str => str + '!';
const split = str => str.split('');

Often code takes the output of one function and uses it as the input to another. This is the idea of a pipeline. Data in, data out.

split(appendExclamationPoints(toUpperCase('hello world'))) 
// ["HELLO", "WORLD!"]

While the above works, it isn’t the easiest to read. A simpler abstraction is a single function that can be invoked with some string passed as the parameter.

function appendExclamationPointAndSplitOnSpace(someString) {
    return (someString.toUpperCase() + '!').split();
}

appendExclamationPointAndSplitOnSpaceagic('hello world') 
// ["Hello", "World!"]

The above function, while meeting the requirements perfectly, isn’t necessarily clean code. It uses an imperative style, specifying each operation to perform to get the desired result. While it may be simple enough to read and understand, a more declarative style would be even easier.

Functional programming can help simplify the above through a helper function called

compose. Compose accepts an arbitrary number of functions, and returns a new function that runs each of the functions passed in such that the output of the previous functions is used as the input to the next

t appendExclamationPointAndSplitOnSpace = compose(
    split, 
    appendExclamationPoints, 
    toUpperCase
);

appendExclamationPointAndSplitOnSpace('hello world') 
// ["Hello", "World!"]

Note that the functions execute in a right to left wrapping manner similar to the original example. That is,

splitinvokes the result ofappendExclamationPointswhich invokes the result oftoUpperCase. This results in a declarative style, with no direct function calls or references to the data and methods that exist on the data type. A new function is created that accepts the data and computes the result. Most importantly, we’re able to build the new function from existing smaller functions that we already have or are trivial to write.

Composing functions requires adherence to the following intuitive rule. The output type of function A must match the input type of function B given that B runs with the output from function A. In a practical example, if a function that returns a number is composed with a function that expects a string, some unexpected errors might creep in.

Various implementations of

composecan be found in Lodash, Redux, and other JavaScript libraries. Its certainly not magical, and can be written in under 10 lines.

#functional-programming #javascript #reactjs #composition #pure-functions #compositions-in-javascript #compositions-in-react #javascript-top-story

Carmen  Grimes

Carmen Grimes

1595494844

How to start an electric scooter facility/fleet in a university campus/IT park

Are you leading an organization that has a large campus, e.g., a large university? You are probably thinking of introducing an electric scooter/bicycle fleet on the campus, and why wouldn’t you?

Introducing micro-mobility in your campus with the help of such a fleet would help the people on the campus significantly. People would save money since they don’t need to use a car for a short distance. Your campus will see a drastic reduction in congestion, moreover, its carbon footprint will reduce.

Micro-mobility is relatively new though and you would need help. You would need to select an appropriate fleet of vehicles. The people on your campus would need to find electric scooters or electric bikes for commuting, and you need to provide a solution for this.

To be more specific, you need a short-term electric bike rental app. With such an app, you will be able to easily offer micro-mobility to the people on the campus. We at Devathon have built Autorent exactly for this.

What does Autorent do and how can it help you? How does it enable you to introduce micro-mobility on your campus? We explain these in this article, however, we will touch upon a few basics first.

Micro-mobility: What it is

micro-mobility

You are probably thinking about micro-mobility relatively recently, aren’t you? A few relevant insights about it could help you to better appreciate its importance.

Micro-mobility is a new trend in transportation, and it uses vehicles that are considerably smaller than cars. Electric scooters (e-scooters) and electric bikes (e-bikes) are the most popular forms of micro-mobility, however, there are also e-unicycles and e-skateboards.

You might have already seen e-scooters, which are kick scooters that come with a motor. Thanks to its motor, an e-scooter can achieve a speed of up to 20 km/h. On the other hand, e-bikes are popular in China and Japan, and they come with a motor, and you can reach a speed of 40 km/h.

You obviously can’t use these vehicles for very long commutes, however, what if you need to travel a short distance? Even if you have a reasonable public transport facility in the city, it might not cover the route you need to take. Take the example of a large university campus. Such a campus is often at a considerable distance from the central business district of the city where it’s located. While public transport facilities may serve the central business district, they wouldn’t serve this large campus. Currently, many people drive their cars even for short distances.

As you know, that brings its own set of challenges. Vehicular traffic adds significantly to pollution, moreover, finding a parking spot can be hard in crowded urban districts.

Well, you can reduce your carbon footprint if you use an electric car. However, electric cars are still new, and many countries are still building the necessary infrastructure for them. Your large campus might not have the necessary infrastructure for them either. Presently, electric cars don’t represent a viable option in most geographies.

As a result, you need to buy and maintain a car even if your commute is short. In addition to dealing with parking problems, you need to spend significantly on your car.

All of these factors have combined to make people sit up and think seriously about cars. Many people are now seriously considering whether a car is really the best option even if they have to commute only a short distance.

This is where micro-mobility enters the picture. When you commute a short distance regularly, e-scooters or e-bikes are viable options. You limit your carbon footprints and you cut costs!

Businesses have seen this shift in thinking, and e-scooter companies like Lime and Bird have entered this field in a big way. They let you rent e-scooters by the minute. On the other hand, start-ups like Jump and Lyft have entered the e-bike market.

Think of your campus now! The people there might need to travel short distances within the campus, and e-scooters can really help them.

How micro-mobility can benefit you

benefits-micromobility

What advantages can you get from micro-mobility? Let’s take a deeper look into this question.

Micro-mobility can offer several advantages to the people on your campus, e.g.:

  • Affordability: Shared e-scooters are cheaper than other mass transportation options. Remember that the people on your campus will use them on a shared basis, and they will pay for their short commutes only. Well, depending on your operating model, you might even let them use shared e-scooters or e-bikes for free!
  • Convenience: Users don’t need to worry about finding parking spots for shared e-scooters since these are small. They can easily travel from point A to point B on your campus with the help of these e-scooters.
  • Environmentally sustainable: Shared e-scooters reduce the carbon footprint, moreover, they decongest the roads. Statistics from the pilot programs in cities like Portland and Denver showimpressive gains around this key aspect.
  • Safety: This one’s obvious, isn’t it? When people on your campus use small e-scooters or e-bikes instead of cars, the problem of overspeeding will disappear. you will see fewer accidents.

#android app #autorent #ios app #mobile app development #app like bird #app like bounce #app like lime #autorent #bird scooter business model #bird scooter rental #bird scooter rental cost #bird scooter rental price #clone app like bird #clone app like bounce #clone app like lime #electric rental scooters #electric scooter company #electric scooter rental business #how do you start a moped #how to start a moped #how to start a scooter rental business #how to start an electric company #how to start electric scooterrental business #lime scooter business model #scooter franchise #scooter rental business #scooter rental business for sale #scooter rental business insurance #scooters franchise cost #white label app like bird #white label app like bounce #white label app like lime

Carmen  Grimes

Carmen Grimes

1595491178

Best Electric Bikes and Scooters for Rental Business or Campus Facility

The electric scooter revolution has caught on super-fast taking many cities across the globe by storm. eScooters, a renovated version of old-school scooters now turned into electric vehicles are an environmentally friendly solution to current on-demand commute problems. They work on engines, like cars, enabling short traveling distances without hassle. The result is that these groundbreaking electric machines can now provide faster transport for less — cheaper than Uber and faster than Metro.

Since they are durable, fast, easy to operate and maintain, and are more convenient to park compared to four-wheelers, the eScooters trend has and continues to spike interest as a promising growth area. Several companies and universities are increasingly setting up shop to provide eScooter services realizing a would-be profitable business model and a ready customer base that is university students or residents in need of faster and cheap travel going about their business in school, town, and other surrounding areas.

Electric Scooters Trends and Statistics

In many countries including the U.S., Canada, Mexico, U.K., Germany, France, China, Japan, India, Brazil and Mexico and more, a growing number of eScooter users both locals and tourists can now be seen effortlessly passing lines of drivers stuck in the endless and unmoving traffic.

A recent report by McKinsey revealed that the E-Scooter industry will be worth― $200 billion to $300 billion in the United States, $100 billion to $150 billion in Europe, and $30 billion to $50 billion in China in 2030. The e-Scooter revenue model will also spike and is projected to rise by more than 20% amounting to approximately $5 billion.

And, with a necessity to move people away from high carbon prints, traffic and congestion issues brought about by car-centric transport systems in cities, more and more city planners are developing more bike/scooter lanes and adopting zero-emission plans. This is the force behind the booming electric scooter market and the numbers will only go higher and higher.

Companies that have taken advantage of the growing eScooter trend develop an appthat allows them to provide efficient eScooter services. Such an app enables them to be able to locate bike pick-up and drop points through fully integrated google maps.

List of Best Electric Bikes for Rental Business or Campus Facility 2020:

It’s clear that e scooters will increasingly become more common and the e-scooter business model will continue to grab the attention of manufacturers, investors, entrepreneurs. All this should go ahead with a quest to know what are some of the best electric bikes in the market especially for anyone who would want to get started in the electric bikes/scooters rental business.

We have done a comprehensive list of the best electric bikes! Each bike has been reviewed in depth and includes a full list of specs and a photo.

Billy eBike

mobile-best-electric-bikes-scooters https://www.kickstarter.com/projects/enkicycles/billy-were-redefining-joyrides

To start us off is the Billy eBike, a powerful go-anywhere urban electric bike that’s specially designed to offer an exciting ride like no other whether you want to ride to the grocery store, cafe, work or school. The Billy eBike comes in 4 color options – Billy Blue, Polished aluminium, Artic white, and Stealth black.

Price: $2490

Available countries

Available in the USA, Europe, Asia, South Africa and Australia.This item ships from the USA. Buyers are therefore responsible for any taxes and/or customs duties incurred once it arrives in your country.

Features

  • Control – Ride with confidence with our ultra-wide BMX bars and a hyper-responsive twist throttle.
  • Stealth- Ride like a ninja with our Gates carbon drive that’s as smooth as butter and maintenance-free.
  • Drive – Ride further with our high torque fat bike motor, giving a better climbing performance.
  • Accelerate – Ride quicker with our 20-inch lightweight cutout rims for improved acceleration.
  • Customize – Ride your own way with 5 levels of power control. Each level determines power and speed.
  • Flickable – Ride harder with our BMX /MotoX inspired geometry and lightweight aluminum package

Specifications

  • Maximum speed: 20 mph (32 km/h)
  • Range per charge: 41 miles (66 km)
  • Maximum Power: 500W
  • Motor type: Fat Bike Motor: Bafang RM G060.500.DC
  • Load capacity: 300lbs (136kg)
  • Battery type: 13.6Ah Samsung lithium-ion,
  • Battery capacity: On/off-bike charging available
  • Weight: w/o batt. 48.5lbs (22kg), w/ batt. 54lbs (24.5kg)
  • Front Suspension: Fully adjustable air shock, preload/compression damping /lockout
  • Rear Suspension: spring, preload adjustment
  • Built-in GPS

Why Should You Buy This?

  • Riding fun and excitement
  • Better climbing ability and faster acceleration.
  • Ride with confidence
  • Billy folds for convenient storage and transportation.
  • Shorty levers connect to disc brakes ensuring you stop on a dime
  • belt drives are maintenance-free and clean (no oil or lubrication needed)

**Who Should Ride Billy? **

Both new and experienced riders

**Where to Buy? **Local distributors or ships from the USA.

Genze 200 series e-Bike

genze-best-electric-bikes-scooters https://www.genze.com/fleet/

Featuring a sleek and lightweight aluminum frame design, the 200-Series ebike takes your riding experience to greater heights. Available in both black and white this ebike comes with a connected app, which allows you to plan activities, map distances and routes while also allowing connections with fellow riders.

Price: $2099.00

Available countries

The Genze 200 series e-Bike is available at GenZe retail locations across the U.S or online via GenZe.com website. Customers from outside the US can ship the product while incurring the relevant charges.

Features

  • 2 Frame Options
  • 2 Sizes
  • Integrated/Removable Battery
  • Throttle and Pedal Assist Ride Modes
  • Integrated LCD Display
  • Connected App
  • 24 month warranty
  • GPS navigation
  • Bluetooth connectivity

Specifications

  • Maximum speed: 20 mph with throttle
  • Range per charge: 15-18 miles w/ throttle and 30-50 miles w/ pedal assist
  • Charging time: 3.5 hours
  • Motor type: Brushless Rear Hub Motor
  • Gears: Microshift Thumb Shifter
  • Battery type: Removable Samsung 36V, 9.6AH Li-Ion battery pack
  • Battery capacity: 36V and 350 Wh
  • Weight: 46 pounds
  • Derailleur: 8-speed Shimano
  • Brakes: Dual classic
  • Wheels: 26 x 20 inches
  • Frame: 16, and 18 inches
  • Operating Mode: Analog mode 5 levels of Pedal Assist Thrott­le Mode

Norco from eBikestore

norco-best-electric-bikes-scooters https://ebikestore.com/shop/norco-vlt-s2/

The Norco VLT S2 is a front suspension e-Bike with solid components alongside the reliable Bosch Performance Line Power systems that offer precise pedal assistance during any riding situation.

Price: $2,699.00

Available countries

This item is available via the various Norco bikes international distributors.

Features

  • VLT aluminum frame- for stiffness and wheel security.
  • Bosch e-bike system – for their reliability and performance.
  • E-bike components – for added durability.
  • Hydraulic disc brakes – offer riders more stopping power for safety and control at higher speeds.
  • Practical design features – to add convenience and versatility.

Specifications

  • Maximum speed: KMC X9 9spd
  • Motor type: Bosch Active Line
  • Gears: Shimano Altus RD-M2000, SGS, 9 Speed
  • Battery type: Power Pack 400
  • Battery capacity: 396Wh
  • Suspension: SR Suntour suspension fork
  • Frame: Norco VLT, Aluminum, 12x142mm TA Dropouts

Bodo EV

bodo-best-electric-bikes-scootershttp://www.bodoevs.com/bodoev/products_show.asp?product_id=13

Manufactured by Bodo Vehicle Group Limited, the Bodo EV is specially designed for strong power and extraordinary long service to facilitate super amazing rides. The Bodo Vehicle Company is a striking top in electric vehicles brand field in China and across the globe. Their Bodo EV will no doubt provide your riders with high-level riding satisfaction owing to its high-quality design, strength, breaking stability and speed.

Price: $799

Available countries

This item ships from China with buyers bearing the shipping costs and other variables prior to delivery.

Features

  • Reliable
  • Environment friendly
  • Comfortable riding
  • Fashionable
  • Economical
  • Durable – long service life
  • Braking stability
  • LED lighting technology

Specifications

  • Maximum speed: 45km/h
  • Range per charge: 50km per person
  • Charging time: 8 hours
  • Maximum Power: 3000W
  • Motor type: Brushless DC Motor
  • Load capacity: 100kg
  • Battery type: Lead-acid battery
  • Battery capacity: 60V 20AH
  • Weight: w/o battery 47kg

#android app #autorent #entrepreneurship #ios app #minimum viable product (mvp) #mobile app development #news #app like bird #app like bounce #app like lime #autorent #best electric bikes 2020 #best electric bikes for rental business #best electric kick scooters 2020 #best electric kickscooters for rental business #best electric scooters 2020 #best electric scooters for rental business #bird scooter business model #bird scooter rental #bird scooter rental cost #bird scooter rental price #clone app like bird #clone app like bounce #clone app like lime #electric rental scooters #electric scooter company #electric scooter rental business #how do you start a moped #how to start a moped #how to start a scooter rental business #how to start an electric company #how to start electric scooterrental business #lime scooter business model #scooter franchise #scooter rental business #scooter rental business for sale #scooter rental business insurance #scooters franchise cost #white label app like bird #white label app like bounce #white label app like lime

Rahul Jangid

1622207074

What is JavaScript - Stackfindover - Blog

Who invented JavaScript, how it works, as we have given information about Programming language in our previous article ( What is PHP ), but today we will talk about what is JavaScript, why JavaScript is used The Answers to all such questions and much other information about JavaScript, you are going to get here today. Hope this information will work for you.

Who invented JavaScript?

JavaScript language was invented by Brendan Eich in 1995. JavaScript is inspired by Java Programming Language. The first name of JavaScript was Mocha which was named by Marc Andreessen, Marc Andreessen is the founder of Netscape and in the same year Mocha was renamed LiveScript, and later in December 1995, it was renamed JavaScript which is still in trend.

What is JavaScript?

JavaScript is a client-side scripting language used with HTML (Hypertext Markup Language). JavaScript is an Interpreted / Oriented language called JS in programming language JavaScript code can be run on any normal web browser. To run the code of JavaScript, we have to enable JavaScript of Web Browser. But some web browsers already have JavaScript enabled.

Today almost all websites are using it as web technology, mind is that there is maximum scope in JavaScript in the coming time, so if you want to become a programmer, then you can be very beneficial to learn JavaScript.

JavaScript Hello World Program

In JavaScript, ‘document.write‘ is used to represent a string on a browser.

<script type="text/javascript">
	document.write("Hello World!");
</script>

How to comment JavaScript code?

  • For single line comment in JavaScript we have to use // (double slashes)
  • For multiple line comments we have to use / * – – * /
<script type="text/javascript">

//single line comment

/* document.write("Hello"); */

</script>

Advantages and Disadvantages of JavaScript

#javascript #javascript code #javascript hello world #what is javascript #who invented javascript

Hire Dedicated JavaScript Developers -Hire JavaScript Developers

It is said that a digital resource a business has must be interactive in nature, so the website or the business app should be interactive. How do you make the app interactive? With the use of JavaScript.

Does your business need an interactive website or app?

Hire Dedicated JavaScript Developer from WebClues Infotech as the developer we offer is highly skilled and expert in what they do. Our developers are collaborative in nature and work with complete transparency with the customers.

The technology used to develop the overall app by the developers from WebClues Infotech is at par with the latest available technology.

Get your business app with JavaScript

For more inquiry click here https://bit.ly/31eZyDZ

Book Free Interview: https://bit.ly/3dDShFg

#hire dedicated javascript developers #hire javascript developers #top javascript developers for hire #hire javascript developer #hire a freelancer for javascript developer #hire the best javascript developers