[willtim]

If you use String for all your data types than you are no better than a dynamic language. There are many string like things that benefit from their own types, e.g. currency, identifiers, post codes. Such types should only be created from a parse of valid strings, i.e. no empty strings, whitespace, illegal values etc. They do not have to be Alan Kay "objects", despite what your language or thought leadership is telling you. They should be values with value-based equality. A modern statically typed language should let you define such a type in a few lines. This is all done in order to make illegal states unrepresentable, which is what type systems are for.

[Jtsummers]

> If you use String for all your data types than you are no better than a dynamic language.

I once read a Haskell (I believe, may have been SML or OCaml, this was a while ago) tutorial (can't find it anymore) that did this. It was infuriating as it completely hid the benefit of the type system. Essentially, details fuzzy, it was creating a calculator program. Imagine parsing is already done and had something like this:

  eval "add" a b = a + b
  eval "sub" a b = a - b
  ...

Where the parsing should've at least turned those strings into something like an Operation type.

Sadly, I've seen similar programs in the wild at work (not using these languages, but with C++, Java, C#) where information is encoded in integers and strings that would be much better encoded in Enums, classes, or other meaningful typed forms.

[willtim]

Yes, every statically-typed language has a dynamic language as a subset. It is up to the author to use and apply types. One can certainly write Haskell where everything is in IO and everything uses Strings.