Re: [Gretl-devel] Default value specification for scalar and integer arguments
On Fri, 3 Jul 2015, Sven Schreiber wrote:
I want to ask whether the following (which is working!) is
actually according to the hansl spec. Consider the session at the
end of the message.
Hansl allows to specify the default value [0] both for 'scalar'
and 'int', without requiring minimum or maximum values. But the
way I read the paragraph "Function parameters: optional
refinements" in the user guide, this would seem to be actually a
syntax error. Instead for non-bool types it should be [::0].
Yes, it seems to me that if you just specify "int foo[0]" this
should mean that foo has a minimum of 0 but no specified max or
default value; and, as you say, "int foo[::0]" should be required to
set a default of 0 with no specified min or max.
But in fact "int foo[0]" seems to be taken as specifying a default
of 0. Presumably this should be fixed; unless perhaps there are lots
of scripts out there that rely on the undocumented and formally
wrong behaviour.
Also (and I feel like having deja-vus again) notice that in the
check2()
function an integer parameter is specified, but if the caller passes 0.5,
there is no type error, instead the argument is converted to its integer
component. I do not think this is obvious, is this documented somewhere?
Well, some time ago we tightened the criterion for accepting an
argument as an "int", for built-in functions, but for user-defined
functions we still have the old behaviour of truncating to int
regardless. I guess the tighter criterion should be applied to user
functions too.
Allin