One way to do it with sort would be to add a method "transitively_depends_on" (t_d_o below) which returns true if there is a dependency chain from the target object to the argument object.

Then you could write something like: 

@objects = sort {
  if ($a->t_d_o($b)) { 
    return -1;
  elsif ($b->t_d_o($a)) {
    return 1;
  }
  else {
    return 0;
  }
} @objects;

[download]
But I would imagine this would be pretty inefficient - t_d_o would have to be a tree walk all of its own I think.

Also, if you're processing a set of dependencies in order to do some processing on the lowest-ranked first (for example, building a set of C/C++ projects, each of which requires its dependencies be built first) you could always not sort at all, but dynamically create a makefile and pipe it to 'make' on STDIN :-)

In reply to Re: Partial sort for dependency graph by jbert
in thread Partial sort for dependency graph by throop

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