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a typo; min/max; partial orders

This page is part of the web mail archives of SRFI 32 from before July 7th, 2015. The new archives for SRFI 32 contain all messages, not just those from before July 7th, 2015.

Hi, I don't know if discussion is still allowed for SRFI 32, but it's
still listed as being in draft mode on the SRFI web site so I figured
I'd post.

First of all, there's a typo in the draft posted at
http://srfi.schemers.org/srfi-32/srfi-32.txt :

  This is due to the definition of equality, given a < comparator:
    (and (not (< x y))
         (not (< y x)))
  The definition is rather different, given a <= comparator:
    (and (<= x y)
         (<= x y))

The last line should read

         (<= y x))

Now, my requests: it would be nice to have generalized versions of the
R5RS `min' and `max' functions, that take a list or vector and a
comparison operator.  Even more generally, they could take a count N,
and return the N least or greatest elements of the list or vector.
Would it be reasonable to put these in SRFI 32, or do they belong
somewhere else?

What I *actually* need right now is a function to compute the list of
minima of a list given a partial order.  Topological sort and
order-preserving insertion would be nice too.  Olin Shivers wrote, in
this forum, "worrying about partial orders is a snare & a delusion".
Does this mean that partial-order algorithms belongs in a separate SRFI?