Re: [Gretl-devel] how to modify bundles in an array?
On Fri, 6 Jan 2017, Sven Schreiber wrote:
Hi,
I'm trying to modify bundles that were previously put into an array (of
bundles):
<hansl>
bundles bs = array(1)
bundle singleb
# try to stuff into the array:
bs[1] = singleb # works
# and modify:
scalar bs[1].num = 3 # fails "not acceptable with arrays"
bs[1].num = 2 # fails "no formula in genr"
</hansl>
So is it simply the case that every bundle must be "finalized"
before putting into a bundles array and then becomes immutable by
design, or is there a bug?
There's an unimplemented feature ;-) No, we have not decided that
array members should be immutable, but neither do we have the
apparatus in place to support modifications of the sort you
describe.
We've been here before: it's difficult to stack up "membership-of"
relationships, the way our parser is currently structured. This
applies particularly to the left-hand side of "genr" expressions but
also to a degree on the right. Note that
eval bs[1].num
doesn't work either. However, I think I see the approach we need to
take to fix this in a general way. I'll try to get this done before
the Athens conference, maybe sooner. The thing is that I'm probably
going to have to work with a private copy of the source to avoid
breaking regular git and snapshots while the work is in progress.
Allin