Undefined function make-index on #-sbcl

[paulvaneecke]

When compiling the package on LW or CCL, the following warning is provided:

The following function is undefined:
GRAPH-UTILS::MAKE-INDEX which is referenced by (METHOD GRAPH-UTILS::ADD-EDGE-INDEX (GRAPH-UTILS::TYPED-GRAPH T T T T ...))

Indeed, the file index.lisp in which this function is defined is only loaded in SBCL (#+sbcl), while the function GRAPH-UTILS::ADD-EDGE-INDEX, which calls GRAPH-UTILS::MAKE-INDEX, is loaded on all platforms (in de file typed-edge-graph-class.lisp).

[kraison]

Ultimately, this is the result of cl-skip-list only supporting sbcl. I never ported it to other lisps, and I never finished a work-around for the indexing methods in graph-utils. You are welcome to port cl-skip-list to your preferred lisp; it shouldn't be too difficult if your lisp supports compare-and-swap.