Priority queue: Difference between revisions

Programming note:   this REXX version allows any number (with or without decimals, say, 5.7) for the priority, including negative numbers.   The priority number can be up to one hundred digits.

<lang rexx>/*REXX program implements a priority queue; with insert/showdisplay/delete the top task. */

numeric digits 100; #=0; @.= /*big #; /*0 tasks; nullify the priority queue.*/

say '══════ inserting tasks.'; call .ins 3 '"Clear drains'"

call .ins 4 '"Feed cat'"

call .ins 5 '"Make tea'"

call .ins 1 '"Solve RC tasks'"

call .ins 2 '"Tax return'"

call .ins 6 '"Relax'"

call .ins 6 '"Enjoy'"

say '══════ deletes top task.'; say .del() /*delete the top task. */

exit /*stick a fork in it, we're all done. */

.del: procedure expose @. #; parse arg p; if p=='' then p=.top(); x=@.p; @.p=; return x

x=@.p; @.p= /*delete the top task entry. */