[clean-list] Some questions on typing in clean

[TAntonini]

Dear Clean community,

I am new to this language, although I know a bit functionnal programming in
Caml
I have some questions about it

-Why are there 2 functions fopen and sfopen ?,
all the more because the compiler can't know at compile time if some files
are shared or not

-More generaly, what's the use of indicating *-attributes in types? This is
a problem
of the compiler , not the programmer; it doesn't change the ("external")
behaviour  of the program,
unlike !-attributes

- when one uses some function like fwrites acting on a console , it changes
the whole world too (!?)
(unless World has no access to console)

-Indeed, why not choosing to have only one big world instead of several ?
(is it a matter of programming style, clarity, speed or something deeper ?)

-Isn't it possible to implement some mechanism for exceptions (abort)
similar to
the one for uniqueness, allowing exceptions carrying data to be defined,
raised and catched
("*type" would mean an object raising no exception, "type" an object raising
at most one)

Thank you in advance for your answers,

Thomas Antonini
mailto:antonini@pps.jussieu.fr