[antonvs]

It definitely is stringly typed. It's just that it's a very normalized example of it, that people don't think of as being an antipattern.

If you want to implement what Yaron Minsky described as "make illegal states unrepresentable", then you use a username type, not a string. That rules out multiple entire classes of illegal states.

If you do that, then when you compile your program, the typechecker can provide a much stronger correctness proof, for more properties. It allows you to do "static debugging" effectively, where you debug your code before it ever even runs.

[wruza]

I don’t get what you’re about. The root comment clearly presents a structure of a separate type. The fact that it happens to contain a single string field is completely irrelevant (what type an actual username should be, a float?). “Stringly typed” is about stringifying non-string values to save typing work and is not applicable here in the slightest.

[antonvs]

I wasn't replying to the root comment, I was replying in the context of the subsequent three comments, specifically:

> > > Crazy that actually using your type system leads to better code.

> > There's a name for this anti-pattern: "Stringly typed"

> I don't think a reasonable person would consider storing a username in a string to be "stringly typed".

#1 was saying that the root comment shows better code using the type system.

#2 was clearly referring to the case where you don't do this as being an anti-pattern.

#3 is saying that storing a username in a string, without wrapping defining a distinct type for it, was not stringly typed. But as I pointed out, it certainly is.

If you doubt my interpretation of #3, the same commenter said this in another comment: "Is it really more 'programmer friendly' to create wrapper types for individual strings all over your codebase?"

[wruza]

I see, my apologies!

[quickthrower2]

I wasn’t sure who was right. I’ll tie break with https://wiki.c2.com/?StringlyTyped= which pretty much says what you just said

[antonvs]

The commenter you're replying to misunderstood the discussion. See my sibling reply.