The intractable problem is not user-created classes and methods so much, though a purely method-oriented system is narrower than proper Lisp generic functions).  It is the implementation-specific class hierarchy/heterarchy, which has not even a de facto standard.

 

See the Green Docket in <https://bitbucket.org/cowan/r7rs-wg1-infra/src/default/ColorDockets.md> for stuff that can't be implemented portably over R7RS-small.

John Cowan          http://vrici.lojban.org/~cowan        xxxxxx@ccil.org
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