Joel Stanley wrote:
I've recently been able to get the SOE/GLFW code up and running from
http://haskell.org/soe/software1.htm
and things are working well under GHCi under Mac OS X.
However, when attempting to compile a simple graphics script using ghc, I'm getting some unexpected link errors:
$ ghc -o mygfx mygfx.hs -iSOE/src compilation IS NOT required /usr/bin/ld: Undefined symbols: _SOE_Blue_closure _SOE_Red_closure _SOE_closeWindow_closure _SOE_drawInWindow_closure _SOE_ellipse_closure _SOE_getKey_closure _SOE_openWindow_closure _SOE_polyline_closure _SOE_runGraphics_closure _SOE_withColor_closure collect2: ld returned 1 exit status
I'm quite new to Haskell, so I'm not sure if there was something special I had to do in order to get the code for the closures generated by ghc.
You can just use --make and ghc will figure things out automatically ghc --make mygfx.hs -o mygfx -iSOE/src (mygfx.hs must be the Main module for that to work, though) If you want to do it by hand/Makefile, you need to compile ("ghc -c") the SOE code first and then link the resulting object files ("ghc -o mygfx SOE.o Draw.o ..."). See http://www.haskell.org/ghc/docs/latest/html/users_guide/ separate-compilation.html#using-make for an example Makefile that shows how it's done. Regards, apfelmus