Re: [Gretl-devel] ema, obs and optional parameter
On Wed, 17 Feb 2010, Sven Schreiber wrote:
Ignacio Diaz-Emparanza schrieb:
> I know this imply more backward-incompatibilities than the current
> state, because in the three cases at left side above, gretl will produce
> an error, but may be easier to display a warning in them ¿isn't it?
[This in regard to requiring use of the obsnum() function in
comparing dates or observation labels against the "obs" index.]
Zwei Seelen wohnen, ach! in meiner Brust (Goethe's Faust; Two
souls,
alas! reside within my breast)
While I'm all for a cleanup along Ignacio's lines (and maybe more, as I
mentioned before), I'm also against script-breaking changes, as you
know. These changes seem to be quite disruptive.
I agree. What we have at the moment is, in effect, "implicit
obsnum() conversion" for syntactical elements that can be
recognized unambiguously as candidates for such conversion. My
suggestion would be:
(a) re-word the manual (and rewrite any packaged scripts that use
this implicit conversion) to use obsnum() explicitly, for the sake
of clarity as Ignacio suggests, but
(b) do not actually remove the implicit conversion, so that old
scripts are not broken. (I'm not aware of any actual problems
generated by the implicit conversion, other than a certain lack of
clarity.)
AFAIK there is a general idea floating around to have a release
at some point with a lot of backward incompatibilities, and of
course also a lot of cleanups. Jack started a wiki page about
it. Maybe it's time to make some concrete plans for gretl 2.0 or
whatever it will be called? Like for the next gretl conference,
or 02/02 next year...
OK by me.
Allin.