> As a result I have not found this article a good one to share with junior developers to help them understand how to design types to capture the notion of validity, and to replace validation with narrowing type conversions (which amount to ‘parsing’ when the original type is something very loose like a string, a JSON blob, or a dictionary).
I think a common belief among programmers is that the true constructive modeling approach presented in the first blog post is not practical in languages that aren’t Haskell, so they do the “smart constructor” approach discussed in the link above instead. However, I think that isn’t actually true, it’s just a difference in how respective communities think about their type systems. In fact, you can definitely do constructive data modeling in other type systems, and I gave some examples using TypeScript in this blog post: https://lexi-lambda.github.io/blog/2020/08/13/types-as-axiom...
This is sort of true. It is a good technique, but it is a different technique. I went into how it is different in quite some detail in this followup blog post: https://lexi-lambda.github.io/blog/2020/11/01/names-are-not-...
I think a common belief among programmers is that the true constructive modeling approach presented in the first blog post is not practical in languages that aren’t Haskell, so they do the “smart constructor” approach discussed in the link above instead. However, I think that isn’t actually true, it’s just a difference in how respective communities think about their type systems. In fact, you can definitely do constructive data modeling in other type systems, and I gave some examples using TypeScript in this blog post: https://lexi-lambda.github.io/blog/2020/08/13/types-as-axiom...