Time for an 2014 update…

Task/Singly-linked-list-Element-insertion/PL-I/singly-linked-list-element-insertion.pli

@@ -0,0 +1,7 @@
+/* Let H be a pointer to a node in a one-way-linked list. */
+/* Insert an element, whose value is given by variable V, following that node. */
+
+allocate node set (Q);
+node.p = H; /* The new node now points at the list where we want to insert it. */
+node.value = V;
+H->p = Q;   /* Break the list at H, and point it at the new node. */

Task/Singly-linked-list-Element-insertion/REXX/singly-linked-list-element-insertion.rexx

@@ -0,0 +1,54 @@
+/*REXX program demonstrates how to create and show a single-linked list.*/
+@.=0                                   /*define a null linked list.     */
+call set@ 3                            /*linked list:  12 Proth primes. */
+call set@ 5
+call set@ 13
+call set@ 17
+call set@ 41
+call set@ 97
+call set@ 113
+call set@ 193
+call set@ 241
+call set@ 257
+call set@ 353
+call set@ 449
+call list@
+     after = 97                        /* ◄──── REXX code to do insert. */
+     newVal=100                        /* ◄────   "    "   "  "    "    */
+     #=@..after                        /* ◄────   "    "   "  "    "    */
+     call ins@ #,newVal                /* ◄────   "    "   "  "    "    */
+say
+say 'a new value of' newval "has been inserted after element value:" after
+call list@
+exit                                   /*stick a fork in it, we're done.*/
+/*──────────────────────────────────INS@ subroutine─────────────────────*/
+ins@:  procedure expose @.;  parse arg #,y
+@._last=@._last+1                      /*bump number of list elements.  */
+_=@._last
+@._._value=y                           /*define new value list element. */
+@._._next=@.#._next
+@.#._next=_
+@..y=_                                 /*set a locator pointer to self. */
+@.max_width=max(@.max_width,length(y)) /*set maximum width of any value.*/
+return                                 /*return to invoker of this sub. */
+/*──────────────────────────────────LIST@ subroutine────────────────────*/
+list@: say;  w=max(7, @.max_width )    /*use the max width of nums or 7.*/
+say center('item',6)        center('value',w)        center('next',6)
+say center(''    ,6,'─')    center(''     ,w,'─')    center(''    ,6,'─')
+p=1
+        do j=1  until p==0      /*show all entries of linked list*/
+        say  right(j,6)   right(@.p._value,w)   right(@.p._next,6)
+        p=@.p._next
+        end   /*j*/
+return
+/*──────────────────────────────────SET@ subroutine─────────────────────*/
+set@: procedure expose @.; parse arg y /*get element to be added to list*/
+_=@._last                              /*set the previous last element. */
+n=_+1                                  /*bump last ptr in linked list.  */
+@._._next=n                            /*set the  next  pointer value.  */
+@._last=n                              /*define next item in linked list*/
+@.n._value=y                           /*set item to the value specified*/
+@.n._next=0                            /*set the  next  pointer value.  */
+@..y=n                                 /*set a locator pointer to self. */
+@.max_width=max(@.max_width,length(y)) /*set maximum width of any value.*/
+return                                 /*return to invoker of this sub. */