September 2017 Update

Task/Sorting-algorithms-Shell-sort/OoRexx/sorting-algorithms-shell-sort.rexx

@@ -0,0 +1,77 @@
+/* Rexx */
+-- --- Main --------------------------------------------------------------------
+call demo
+return
+exit
+
+-- -----------------------------------------------------------------------------
+--  Shell sort implementation
+-- -----------------------------------------------------------------------------
+::routine shellSort
+  use arg ra
+
+  n = ra~items()
+  inc = format(n / 2.0,, 0) -- rounding
+  loop label inc while inc > 0
+    loop i_ = inc to n - 1
+      temp = ra~get(i_)
+      j_ = i_
+      loop label j_ while j_ >= inc
+        if \(ra~get(j_ - inc) > temp) then leave j_
+        ra~set(j_, ra~get(j_ - inc))
+        j_ = j_ - inc
+        end j_
+      ra~set(j_, temp)
+      end i_
+    inc = format(inc / 2.2,, 0) -- rounding
+    end inc
+
+  return ra
+
+-- -----------------------------------------------------------------------------
+-- Demonstrate the implementation
+-- -----------------------------------------------------------------------------
+::routine demo
+
+placesList = .nlist~of( -
+    "UK  London",     "US  New York",   "US  Boston",     "US  Washington" -
+  , "UK  Washington", "US  Birmingham", "UK  Birmingham", "UK  Boston"     -
+)
+
+lists = .array~of( -
+    placesList -
+  , shellSort(placesList~copy()) -
+  )
+
+loop ln = 1 to lists~items()
+  cl = lists[ln]
+  loop ct = 0 to cl~items() - 1
+    say right(ct + 1, 4)':' cl[ct]
+    end ct
+    say
+  end ln
+  return
+
+-- -----------------------------------------------------------------------------
+::routine isTrue
+  return 1 == 1
+
+-- -----------------------------------------------------------------------------
+::routine isFalse
+  return \isTrue()
+
+-- -----------------------------------------------------------------------------
+-- Helper class.  Map get and set methods for easier conversion from java.util.List
+-- -----------------------------------------------------------------------------
+::class NList mixinclass List public
+
+-- Map get() to at()
+::method get
+  use arg ix
+  return self~at(ix)
+
+-- Map set() to put()
+::method set
+  use arg ix, item
+  self~put(item, ix)
+  return