Doubly-linked list/Element insertion: Difference between revisions

=={{header|Phix}}==

See also [[Doubly-linked_list/Traversal#Phix|Doubly-linked_list/Traversal]].

<lang Phix>enum NEXT,PREV,DATA

constant empty_dll = {{1,1}}

sequence dll = empty_dll

procedure insert_after(object data, integer pos=1)

integer prv = dll[pos][PREV]

dll = append(dll,{pos,prv,data})

if prv!=0 then

dll[prv][NEXT] = length(dll)

end if

dll[pos][PREV] = length(dll)

end procedure

insert_after("ONE")

insert_after("TWO")

insert_after("THREE")

?dll</lang>

{{out}}

<pre>

{{2,4},{3,1,"ONE"},{4,2,"TWO"},{1,3,"THREE"}}

</pre>