Initial data commit

Task/Sorting-algorithms-Quicksort/Fexl/sorting-algorithms-quicksort.fexl

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+# (sort xs) is the ordered list of all elements in list xs.
+# This version preserves duplicates.
+\sort==
+    (\xs
+    xs [] \x\xs
+    append (sort; filter (gt x) xs);   # all the items less than x
+    cons x; append (filter (eq x) xs); # all the items equal to x
+    sort; filter (lt x) xs             # all the items greater than x
+    )
+
+# (unique xs) is the ordered list of unique elements in list xs.
+\unique==
+    (\xs
+    xs [] \x\xs
+    append (unique; filter (gt x) xs); # all the items less than x
+    cons x;                            # x itself
+    unique; filter (lt x) xs           # all the items greater than x
+    )