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TypeScript News Thursday, March 29 Code, Imperative programmer, Typescript & more…

TypeScript News TLDR / Table of Contents

  • In this post, youll see how to take advantage of generators to make the monadic code more readable.
  • As a reminder, we implemented the function in the following way: – – Obviously, the code is more readable than the original version which involved three levels of nesting.
  • This means that we can inject some code to be executed between statements of given function.
  • We could try to write a function that takes a generator function (a function with some statements) and injects the logic of handling empty results.
  • It will take a generator function and produce instance containing the result of the computation.

Tags: code, imperative programmer, monadic code, imperative code,

  • TypeScript is an open source language backed by Microsoft that provides optional static typing while remaining a strict syntactical superset of JavaScript.
  • The big new feature in TypeScript 2.8 is the support for conditional types, which borrows from JavaScript’s familiar conditional — or ternary operator, ?
  • In TypeScript 2.8 the new functionality involving the ternary operator opens up all kinds of possibilities, Microsoft’s Daniel Rosenwasser explained: – – Although that’s the simplest example, the new feature can be put to many more complicated use cases, including working with generics.
  • The new conditional type functionality stems from a pull request for Microsoft’s open source programming language announced by Technical Fellow Anders Hejlsberg on Jan. 20.
  • Speaking of which, Rosenwasser also summarized the following features in TypeScript 2.8: – – We hope that TypeScript 2.8 pushes the envelope further to provide a type system that can truly represent the nature of JavaScript as a language, Rosenwasser concluded.

Tags: TypeScript, new feature, Boolean conditional expression, conditional types, conditional type functionality

  • This example shows a component with calls inside of : – – The simplest refactor for this type of component is to move state initialization to the constructor or to a property initializer, like so: – – Here is an example of a component that uses to fetch external data:…
  • Rather than passing a subscribable prop as we did in the example above, we could use to pass in the subscribed value: – – Here is an example of a component that uses the legacy lifecycle to update based on new values: – – Although the above code is not…
  • (That lifecycle is called when a component is created and each time it receives new props): – – Here is an example of a component that calls an external function when its internal state changes: – – Sometimes people use out of a misplaced fear that by the time fires,…
  • You can also use the new lifecycle to clear stale data before rendering the new props: – – Here is an example of a component that reads a property from the DOM before an update in order to maintain scroll position within a list: – – In the above example,…
  • This package polyfills components so that the new and lifecycles will also work with older versions of React (0.14.9+).

Tags: class ExampleComponent, state, React, React.Component, return null