TypeScript and NodeJS, I'm sold

TypeScript is a typed superset of JavaScript that compiles to plain JavaScript, the way you expect it to be.

I’ve heard of it a long time ago, but recently with TypeScript 1.7 it got async functions, which means you can awaitasynchronous function calls, similarly to C#, Vala, Go and other languages with syntax support for concurrency. That makes coroutines a pleasant experience compared to plain JavaScript. That’s also the main reason why I didn’t choose Dart.

I’m writing a NodeJS application so I decided to give it a go. Here’s my personal tour of TypeScript and why I’m sold to using it.

Does it complain when using undeclared variables?

console.log(foo);

Cannot find name 'foo'.

Sold!

Does it infer types?

var foo = 123;
foo = "bar";

Type 'string' is not assignable to type 'number'.

Sold!

Does it support async arrow functions?

async function foo() {
}
var bar = async () => { await (foo); };

Sold!

Does it support sum types?

var foo: number | string;
foo = 123;
foo = "bar";

Sold!

Does it play nice with CommonJS/AMD imports and external libraries?

Yes, it does very well. Sold!

Is it easy to migrate from and to JavaScript?

Yes. TypeScript makes use of latest ECMAScript features in its syntax when possible, so that JavaScript -> TypeScript is as painless as possible. Sold!

Also to go back from TypeScript to JavaScript, either use the generated code, or remove all the type annotations in the code by yourself.

Does it have non-nullable variables?

No. This is mostly due to the JavaScript nature though. But I’m sure the TypeScript community will come up with a nice solution throughout this topic.

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I’m going to use TypeScript wherever I can in this new year instead of plain JavaScript. In particular, I’m rewriting my latest NodeJS application in TypeScript right now.

I hope it will be a great year for this language. The project is exceptionally active, and I hope to contribute back to it.

Inline commenting system for blog sites

One side of the idea:
Lately I've seen some comment systems that inline comments in the text itself, see an example here.

Other side of the idea:
I've implemented a couple of unsupervised algorithms for news text extraction from web pages in Javascript, and they work generally well. They're also capable of splitting the news text into paragraphs and avoid image captions or other unrelated text.

The idea:
Merge the two ideas, as a new commenting service (like Disqus) for blogs, in a modern and interesting way.

1. The algorithms are capable of extracting the news text from your blog and splitting it into paragraphs.
2. For each paragraph, add a seamless event so that when the user overs a paragraph with the mouse, a comment action button appears.
3. When clicking the comment button a popup will appear showing a text box at the top where you can write the comment, and the list of comments at the bottom that are related to that paragraph only. (I please you, let the user order comments by date.)
4. Optional killer feature: together with the text box, you can also choose to add two buttons: "This is true", "This is false", so that there's a kind of voting system about the truth value of that paragraph from the readers perspective.
5. Once you send the comment, that comment is tied to that paragraph.
6. Give the possibility to create comments the old way, in case the user does not want to strictly relate the comment to a paragraph.
7. Give the possibility to show all the comments at the bottom of the page (button "Show all comments"). If a comment is related to a paragraph, insert an anchor to the paragraph.

Given that the blogger shouldn't add any additional HTML code for the paragraphs because of the unsupervised news extraction algorithms, the comment service API will not differ in any way than the current ones being used.

Problems of this approach:

• There's no clear chronology for the user between comments of two different paragraphs. In my opinion, this shouldn't be a big deal, as long as comments between two paragraphs are unrelated.
• If a paragraph is edited/deleted, what happens to the comments? One solution is to not show them in the text, but add a button "Show obsolete comments" at the buttom of the page, or rather show them unconditionally.
• The unsupervised algorithm may fail to identify the post. In that case, the blogger may fall back to manually define the DOM element containing the article.