27 lines
2.5 KiB
Rexx
27 lines
2.5 KiB
Rexx
/*REXX program implements a priority queue; with insert/display/delete the top task. */
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#=0; @.= /*0 tasks; nullify the priority queue.*/
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say '══════ inserting tasks.'; call .ins 3 "Clear drains"
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call .ins 4 "Feed cat"
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call .ins 5 "Make tea"
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call .ins 1 "Solve RC tasks"
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call .ins 2 "Tax return"
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call .ins 6 "Relax"
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call .ins 6 "Enjoy"
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say '══════ showing tasks.'; call .show
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say '══════ deletes top task.'; say .del() /*delete the top task. */
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exit /*stick a fork in it, we're all done. */
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/*──────────────────────────────────────────────────────────────────────────────────────*/
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.del: procedure expose @. #; parse arg p; if p=='' then p=.top(); x=@.p; @.p=; return x
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/*delete the top task entry. */
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/*──────────────────────────────────────────────────────────────────────────────────────*/
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.ins: procedure expose @. #; #=#+1; @.#=arg(1); return # /*entry, P, task.*/
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/*──────────────────────────────────────────────────────────────────────────────────────*/
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.show: procedure expose @. #; do j=1 for #; _=@.j; if _=='' then iterate; say _; end
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return /* [↑] show whole list or just one. */
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/*──────────────────────────────────────────────────────────────────────────────────────*/
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.top: procedure expose @. #; top=; top#=
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do j=1 for #; _=word(@.j,1); if _=='' then iterate
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if top=='' | _>top then do; top=_; top#=j; end
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end /*j*/
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return top#
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