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Introducing TypeLib JS - simplified type detection and debugging

Schemetastic (Rodrigo) on February 07, 2024

If you want to see it in action, check out the project landing page at: typelib.schemetastic.com I do also have a promo short video about the proj...

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Eckehard • Feb 7

I much appreciate your effort! Type checking is super important in Javascript and a nice lib could help to make things easier.

I like your coding style, it is very clear. But as type checks are used often and the lib is included in any project, the code should be thoroughly optimized for size and speed. Maybe arrow functions and a shorter names could save some bytes?

The following routine could be possibly faster and shorter:

var kindsList = [];
// Verify all the properties that are `true`, replace the word `is`, and push it to `kindsList`.
kindsProps.forEach(function (prop) {
     if (inst[prop]) kindsList.push(prop.toLowerCase().replace(/^is/, ''));
});

RegEx-Replace can be very slow. slice(2) would do the same job
instead of forEach->push, you could use "filter":

console.log([1,2,3,4,5,6,7].filter(i => i>3))  // -> [ 4, 5, 6, 7 ]

So, I suppose, your code could be like ths:

let kindsList = kindsProps.filter(prop => inst[prop]).map(p => p.slice(2).toLowerCase())

I did not run this code, but maybe you can take this as an example.

Schemetastic (Rodrigo) • Feb 8

Arrow functions? In a previous version they were detected, but I removed them from the spec... 3 reasons

Couldn't find a satisfying regex (arrow functions can have comments, and be written in different ways, for example, you can even omit the parenthesis)
The only method I know to detect them imply that you verify if it is a function, and it doesn't have a prototype (thanks AI)... but I thought that JS may in the future would add another type of function without a prototype and could break code.
TypeLib is a lot about developer experience... commonly, when you need to verify a function is because you would use it as a callback, some devs prefer arrow functions, other normal... I've got to realize that having to differentiate between one or another could be confusing and time-consuming... #I'm-not-a-rapper ... but maybe? Haha

By the way, I'm glad that you reviewed my code and that you liked it, I'm surprised that someone took the time to read it and review it, It took a lot of efforts to write that code in that way. Thanks for your suggestion, I don't know how much using a regex like that could affect performance, but your suggestion is valid, I will consider that for a future version. Really, thanks a lot.