-- mpairs m > L (L _) — sorted-by-key list of [k, v] 2-element lists.
-- Invariant: mpairs m == zip (mkeys m) (mvals m). Use instead of the
-- common `map (fn k > [k (mget m k)]) (mkeys m)` cascade.
pairs>L (L _);m=mset (mset (mset mmap "b" 2) "a" 1) "c" 3;mpairs m
-- Empty map returns an empty list.
empty>L (L _);mpairs mmap
-- Numeric keys sort numerically (not lexicographically): 2 < 5 < 10.
nums>L (L _);m=mset (mset (mset mmap 10 "a") 2 "b") 5 "c";mpairs m
-- Iterate both key and value in one pass using mpairs.
-- Common pattern replacing: map (k:t>L _;[k (mget m k)]) (mkeys m)
iter>_
m=mset (mset (mset mmap "x" 10) "y" 20) "z" 30
fld {acc pair > [acc, pair]} [] (mpairs m)
-- run: pairs
-- out: [[a, 1], [b, 2], [c, 3]]
-- run: empty
-- out: []
-- run: nums
-- out: [[2, b], [5, c], [10, a]]
-- run: iter
-- out: [[x, 10], [y, 20], [z, 30]]