On May 14, 2011, at 4:34 AM, Rob Beezer wrote: > I do not have too many versions of Sage available to me at the moment, > but: > > Your example works properly on 4.6.2.alpha3 > > Your example fails on 4.6.2.alpha4 and 4.7.rc0 > > The failure is at the same place as in the initial report. > > Pierre - What version are you using? > > The only ticket merged between those two alphas that looks like it > could possibly be relevant is > > http://trac.sagemath.org/sage_trac/ticket/11000 > > which has to do multi-line input to GAP.
I'm the author of that patch, so I thought I would take a look at it. It turns out it may actually have affected the bug, which is to say it may have revealed the bug in some cases. Basically the problem is the input is getting sent to GAP via a temp file (for "large" input) and this causes it not to return any output which permgroup.py then uses to initialize a group. I'm not sure if the "bug" is that it gets sent to a temp file or that permgroup expects there to be output. I suspect the latter though this problem is probably quite ubiquitous. You can "fix" it by never allowing use of a temp file by changing line 465 of devel/sage/sage/interfaces/gap.py from def _eval_line(self, line, allow_use_file=True, wait_for_prompt=True): to def _eval_line(self, line, allow_use_file=False, wait_for_prompt=True): Perhaps the limit for temp file usage should be increased from 100 to something much higher? This wouldn't eliminate the bug, but it would make it much less frequent, and 100 seems quite low to me. Is there a a trac ticket for this? -Ivan > Rob > > On May 13, 3:04 pm, Pierre <pierre.guil...@gmail.com> wrote: >> Thanks, this works... sometimes. But the following still fails: >> >> sage: G = QuaternionGroup() >> sage: H = direct_product_permgroups([G, G]) >> sage: K= direct_product_permgroups([H, G]) >> >> Gap produced error output >> Syntax error: expression expected >> $sage17:=<permutation group with 6 generators>;; >> ^ >> >> executing $sage17:=<permutation group with 6 generators>;; >> >> any thoughts? > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
