[LinuxCNC/linuxcnc PR#221] stdglue.py: turn `change_epilog()` into generator function

#1 – jepler 于 2017-01-04

looks like the docs may benefit from an update in this area as well, they propose changeprologue / changeepilogue functions which are not generators.

#2 – zultron 于 2017-01-04

@jepler, when a python remap function returns an INTERPOK or INTERPERROR result, there’s no need to reenter the routine: it’s done. I haven’t tried to understand why the remap function doesn’t need to be a generator in these cases, although it does seem to work correctly.

Only when a remap function returns INTERPEXECUTEFINISH, the function must be a generator. The error @dhwiezel saw is the result of asking for the next result from a non-generator function (and that case could probably return a more useful error message if it can be detected).

I did grep around in the source and found no other python functions incorrectly using INTERPEXECUTEFINISH except in configs/sim/axis/orphans/pysubs/remap.py.

So, if one thinks all remap functions must be generators, there’s a lot of search and replace that needs doing in both the source and docs. Otherwise they should be ok, and the docs do discuss the yield INTERPEXECUTEFINISH issue.