Hi Andrew:
First
of all, according to
http://digitalmars.com/d/1.0/index.html D
version
2 is recommended for new projects while D version 1 is just in
maintenance
mode. Obviously we want PLplot to be useful for the
increasing
numbers of D2 users, and obviously from your experience
D1 support
under Linux is getting more problematic in any case. So I
think our
overall goal should be unequivocally to move to D2.
Furthermore, I
think that your idea of generating our D2 bindings with
swig is a
viable idea. For example, from
http://swig.org/Doc2.0/D.html#D_introduction
the D support under swig
sounds pretty solid. The Java module was
the basis of the C# module
which in turn was the basis for the D
module. We already have good
experience with the Java module so it
is reassuring tht the D module
is related to it. Furthermore, the
-d2 option allows swig-generated D
bindings to target D2.
Although
I am a big fan of swig, and I am virtually positive this idea
would
work, I think of swig as a last resort for D since maintaining
our
current htod-generated plplot.d file is probably going to be much
simpler.
Those
who have implemented the D compiler obviously take great pride
in
how easy it is to interface with C from D. For example, see
http://www.d-programming-language.org/interfaceToC.html.
My
understanding from skimming
http://www.d-programming-language.org/htod.html
is that htod is a tool
to automate such interfacing.
So here
are some of my ideas to help implement the goal of moving from
D1 to
D2.
1. Convert our examples code written in D from D1 to D2
following the
ideas at
http://www.d-programming-language.org/D1toD2.html. Note we
have to
do this step regardless of what method we use to
change
bindings/d/plplot.d from D1 to D2.
2. Change our
bindings/d/plplot.d code from D1 to D2. The earliest
version of a D2
compiler was implemented about 5 years ago while
plplot.d was
generated by htod some 4 years ago which is probably why
the plplot.d
result is D1 rather than D2. However, there is now a
more modern
htod you can download from
http://www.d-programming-language.org/htod.html
that was dated two
years ago. I think there is a good chance that
one (updated 3 years
after the earliest version of the D2 compiler
was released) will
produce a D2 version of plplot.d. So it might be
worthwhile to start
over using the latest htod following the cookbook
in
bindings/d/README.txt. Note, I have just now confirmed by doing
the
download and analyzing the results that htod is a Windows
executable.
So it will require access to a Windows platform (wine is
likely to be
suitable and certainly some of our developers have
access to Microsoft
Windows in case htod doesn't work on the wine
platform) to regenerate
plplot.d this way. Of course, if this
regeneration idea does not work
for some reason we could fall back on
hand-editing the current
plplot.d to convert it to D2 following the
ideas in
http://www.d-programming-language.org/D1toD2.html.
Anyhow,
these are just my ideas about some good possibilities for our
fairly
urgent need to move PLplot from D1 to D2, but ultimately we need a
volunteer
to make that happen, and it will be their decision which
path they
want to take to achieve the goal.
