Interface LHAPDF >= 6.0.0

[Juergen Reuter]

This has to be a new interface to be supported, tracking version numbering. We plan for it for 2.2.1.

[Juergen Reuter]

I will try to take that job...

[Juergen Reuter]

LHAPDF 6 installs a script lhapdf in addition to lhapdf-config. That is a possibility to distinguish the two during configuration. Note that after having installed both, lhapdf-config also points to 6.X. Hence, a configuration of WHIZARD to be running with both seems quasi impossible.

[Juergen Reuter]

On the other hand, lhapdf 5.X.X is still correctly running (also inside the WHIZARD tests) when LHAPDF 6.X is installed.

[Juergen Reuter]

Some more thoughts about this: 1) possible renaming of src/lhapdf -> src/lhapdf5 2) new src/lhapdf for the C++ LHAPDF 6 wrapper 3) configure tests for the script lhapdf first which is only present for v6, and then

for lhapdf-config which is for both versions.

4) Will the HOPPET interface be working also for LHAPDF6? Please comment on this.

[Juergen Reuter]

Stuck at the moment, none of the LHAPDF examples runs. Running any of the examples on the LHAPDF page I get an error

terminate called after throwing an instance of 'LHAPDF::ReadError'
  what (): Empty PDF file name given to Info::load
Abort trap: 6

WTF!?

[Juergen Reuter]

As of r5923 all is implemented from my side. Steering PDFs with LHAPDF6 works, running alpha_s from LHAPDF6 works. Two things left open: manual entries for LHAPDF6 and checking that HOPPET also works with LHAPDF6 using the modifications I made. The problem I had before that one global initialization as for Fortran LHAPDF5 is not enough, but the initialization has to take place for both beams. The initialization check for LHAPDF6 also looks whether the C pointer to the LHAPDF object is associated.

[Juergen Reuter]

Done in r5925. PDF calls work, running alphas works, HOPPET calls work. The only open issues might be the problem with the destructor for the C pointers which is left for ticket #623, and maybe support of some of the enhanced features of LHAPDF6 concerning error evaluation etc. But then we can open separate tickets if demanded. Closing.