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julien> (So, according to the Wikipedia definition, it is a first-class value:
julien> http://en.wikipedia.org/wiki/First-class_object)

Hmmm, if I look it up:

wikipedia> can be stored in variables and **data structures**
wikipedia> can be passed as a parameter to a subroutine
wikipedia>can be returned as the result of a subroutine
wikipedia> can be constructed at runtime
wikipedia> has intrinsic identity (independent of any given name)

It fails the data structures part. Nil cannot be stored in data
structures, except in "argument stacks" or how you might call it.
I dont know what is ment with "has intrinsic identity".

julien> -          It is the value given when we don’t know what else
to give (not
julien> defined, unknown value, an error occured, …)

Thank you a lot for bringing that up! In your list it has 3 meanings
already, including even an ellipsis for more! Thats whats likely the
cause the reappearing confusion around it.

I see what I've done here however. _Nobody_ was actually inspired by
the idea of non-nilness. I'm suprised that no-one pointed the "this
language you never heared of", that has non-nullable types and
non-null-pointers. BTW: what does fortran (in its many dialects use?)
I don't know what to make of it, either the idea is incredibly stupid
and a fallback or an anachronism for which we just yet fail to see its
virtue. I'm yet undecided, metaphorical some claim the invention of
the number zero the biggest leap of humanity (over the usually claimed
wheel), so it feels bad to say to any symbol of nothingness to be
suboptimal. Yet a metaphor is just a metaphor and does not necessarily
apply to nullable types. Instead I've activated the
"make-nil-a-first-class-value-crowd" which we knew preexisted, this is
not what I wanted to shoot for. But I'm very thankfull for all who
read the propsoal (yeah I just noticed the typo, a shame), and devoted
their time to share their thoughts about this.

Kind regards, Axel