Re^6: Re-orderable keyed access structure?

I' not irked by the second slice, just exploring the options. Replacing @keyFor with a %keyFor wouldn't work. Once @array has been reordered, the key=>index mappings need an equivalent reordering (hence the second slice), but that would be impossible (or very expensive) using a hash to store them.

Examine what is said, not who speaks.

"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon

Comment on Re^6: Re-orderable keyed access structure?

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Re^7: Re-orderable keyed access structure? by Aristotle (Chancellor) on Aug 14, 2004 at 20:30 UTC
I don't understand your objection. `sub swap_elements_by_idx { my ( $i, $j ) = @_; @actual_data[ $i, $j ] = @actual_data[ $j, $i ]; @key_for{ $i, $j } = @key_for{ $j, $i }; # note this is a hash now @index_of{ @key_for[ $i, $j ] } = @index_of{ @key_for[ $j, $i ] }; }` [download] And it doesn't work any differently for multi-element atomic operations. Makeshifts last the longest.	[reply] [d/l]
Re^8: Re-orderable keyed access structure? by BrowserUk (Patriarch) on Aug 14, 2004 at 20:53 UTC
The objection is that it doesn't do what I need it to. Taking an element from the middle of the stack and moving it to the top or the bottom. `push @array, splice @array, $itemToMove, 1;` [download] Doing this using `swap_elements_by_idx()` would require iterating over the length of both `@actual_data` and `@key_for` arrays. Either of the working schemes is better than this as they only iterate one structure not two. Examine what is said, not who speaks. "Efficiency is intelligent laziness." -David Dunham "Think for yourself!" - Abigail "Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon	[reply] [d/l] [select]