Am Do., 8. Sept. 2022 um 01:29 Uhr schrieb John Cowan <xxxxxx@ccil.org>:

On Wed, Sep 7, 2022 at 6:23 PM Per Bothner <xxxxxx@bothner.com> wrote:

Most do. `list` doesn't but it may not count as "ad-hoc polymorphic":

Right: `list`, like `cons`, `vector`, etc. are universally polymorphic. A vector of promises to deliver integers is not the same as a vector of integers. But `string` can force, because a string element can't be a promise to deliver a character; it should always be an actual character.

Well, in that case, `string` could return a promise instead, turning it into a non-strict procedure.

I want to say by this that it is a non-trivial matter to decide which primitive procedures should be strict and which should be non-strict.  In a truly non-strict programming language, there would be no place for strictness, but even Haskell is not absolutely non-strict.