September Morn Update

Task/Sort-disjoint-sublist/Python/sort-disjoint-sublist-2.py

@@ -0,0 +1,58 @@
+'''Disjoint sublist sorting'''
+
+
+# disjointSort :: [Int] -> [Int] -> [Int]
+def disjointSort(ixs):
+    '''A copy of the list xs, in which the disjoint sublist
+       of items at zero-based indexes ixs is sorted in a default
+       numeric or lexical order.'''
+    def go(xs):
+        ks = sorted(ixs)
+        dct = dict(zip(ks, sorted(xs[k] for k in ks)))
+        return list(dct[i] if i in dct else x for i, x in enumerate(xs))
+    return lambda xs: go(xs)
+
+
+# TEST ----------------------------------------------------
+# main :: IO ()
+def main():
+    '''Tests'''
+
+    print(
+        tabulated('Disjoint sublists at indices [6, 1, 7] sorted:\n')
+        (str)(str)(
+            disjointSort([6, 1, 7])
+        )([
+            [7, 6, 5, 4, 3, 2, 1, 0],
+            ['h', 'g', 'f', 'e', 'd', 'c', 'b', 'a']
+        ])
+    )
+
+
+# Generic functions for test and display ------------------
+
+
+# compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
+def compose(g):
+    '''Function composition.'''
+    return lambda f: lambda x: g(f(x))
+
+
+# tabulated :: String -> (a -> String) ->
+#                        (b -> String) ->
+#                        (a -> b) -> [a] -> String
+def tabulated(s):
+    '''Heading -> x display function -> fx display function ->
+                f -> value list -> tabular string.'''
+    def go(xShow, fxShow, f, xs):
+        w = max(map(compose(len)(xShow), xs))
+        return s + '\n' + '\n'.join(
+            xShow(x).rjust(w, ' ') + ' -> ' + fxShow(f(x)) for x in xs
+        )
+    return lambda xShow: lambda fxShow: lambda f: lambda xs: go(
+        xShow, fxShow, f, xs
+    )
+
+
+if __name__ == '__main__':
+    main()