Just another update

Task/Sorting-algorithms-Selection-sort/REXX/sorting-algorithms-selection-sort.rexx

@@ -1,31 +1,31 @@
-/*REXX program sorts an  array  using  the  selection-sort  method.     */
-@.=''                                  /*assign a default value to stem.*/
-@.1='---The seven hills of Rome:---'
-@.2='=============================='
-@.3='Caelian'
-@.4='Palatine'
-@.5='Capitoline'
-@.6='Virminal'
-@.7='Esquiline'
-@.8='Quirinal'
-@.9='Aventine'
-                      do items=1  until @.items==''      /*find # items.*/
-                      end
-items=items-1                          /*adjust the # of items slightly.*/
-call show@ 'before sort'               /*show the before array elements,*/
-call selectionSort items               /*invoke the selection sort.     */
-call show@ ' after sort'               /*show the  after array elements.*/
+/*REXX program sorts a stemmed array using the selection-sort algorithm.*/
+@.  =                                  /*assign a default value to stem.*/
+@.1 = '---The seven hills of Rome:---'
+@.2 = '=============================='
+@.3 = 'Caelian'
+@.4 = 'Palatine'
+@.5 = 'Capitoline'
+@.6 = 'Virminal'
+@.7 = 'Esquiline'
+@.8 = 'Quirinal'
+@.9 = 'Aventine'
+                do k=1  until @.k==''  /*find the number of array items.*/
+                end   /*k*/            /* [↑]  find the  "null"  item.  */
+items=k-1                              /*adjust the # of items slightly.*/
+call show@  'before sort'              /*show the before array elements,*/
+call selectionSort  items              /*invoke the selection sort.     */
+call show@  ' after sort'              /*show the  after array elements.*/
 exit                                   /*stick a fork in it, we're done.*/
 /*──────────────────────────────────SELECTIONSORT subroutine────────────*/
 selectionSort:  procedure expose @.;  parse arg n
 
-              do j=1  for n-1
-              _=@.j;  p=j;            do k=j+1  to n
-                                      if @.k<_  then do;  _=@.k;  p=k; end
-                                      end    /*k*/
-              if p==j  then iterate
-              _=@.j;   @.j=@.p;   @.p=_
-              end   /*j*/
+         do j=1  for n-1
+         _=@.j;  p=j;            do k=j+1  to n
+                                 if @.k<_  then do;   _=@.k;   p=k;   end
+                                 end   /*k*/
+         if p==j  then iterate         /*if the same, order of items OK.*/
+         _=@.j;   @.j=@.p;   @.p=_     /*swap two items out-of-sequence.*/
+         end   /*j*/
 return
 /*──────────────────────────────────SHOW@ subroutine────────────────────*/
 show@: w=length(items);          do i=1  for items