Show HN: I implemented generics in my programming language
4 comments
·December 15, 2025p0w3n3d
This are merely instanceof switches. Generics mean that you write
fun(a,b): return a+b
and if the a + b is doable, it will be done. You don't need to specify the list of types that accepts this syntax. The difference between this and duck typing is that you can also specify interfaces (or traits in c++) that will say that this type is quackable so fun(a <? implements Quackable>): a.quack()
is reusable. What is the difference between this and simple interface implementation? It took me some time to find this example in the narrowest version possible. class <T has trait Number> Complex(a T, b T):
Complex<T> operator+(Complex<T> other): return new Complex(this.a + other.a, this.b+other.b)
Complex<T> operator-(Complex<T> other): return new Complex(this.a - other.a, this.b-other.b)
Complex<T> operator*(Complex<T> other):
return Complex(this.a * other.a - this.b * other.b, this.a * other.b + this.b * other.a)
The generic renders this code reusable, so if only you can create a new type, let's say vector, that supports +,-, and multiply you can have complex algebra on those vectorsone-punch
You have implemented a form of ‘ad-hoc polymorphism’.
This is different from ‘parametric polymorphism’, which is what people call generics.
mrkeen
You implemented Specifics.
One of my pet-hates is fellow developers who call an implementation 'generic', but when you peek inside, there's just if-statements that (at best) cover the already-known input types.
Usually I point to Generics as an example of what "generic" actually means: You peek inside List<T>, it doesn't know about your type, it does the right thing anyway.
miellaby
You should consider change the name, it looks like a lot like https://haxe.org/
It took a while to implement, though now I have generic functions working in Axe. Documentation, repository and site attached.