IO again ....

[Paul Massey]

Hello,

Since I got caught by this problem (inside my server). Why
is, for example:

:- pred io__write_string(string::in,io__state::di,io__state::uo) is det.

defined in this way ? Shouldn't this really be (not sure of the modes
required here):

:- pred io__write_string(string::in,io__state::di,io__res(io__state)::uo) is det.

for it to be completely logical ? The io__write_string/3 can
fail due to lack of space, disappearance of the device,
etc. and in the current system there's no way to trap this
situation ?

Yours,

Paul.