delete symbol vs setting symbol to nil

[HPW]

Hello,



I have a question about differences between deleting a symbol vs setting a symbol to nil.

When I do some housekeeping myself and want to get a unused symbol out of the (symbols) list,

I use (delete 'symbolname) to delete the content and the symbol itself.



What the difference between them in memory usage?

Is deleting and recreating a symbol the same performance as nil it an reused it later?



Regards



Hans-Peter

[HPW]

Ok, making this little benchmark:

> (time(dotimes (zCount 10000)(set(sym(string "TEST" zCount))10)))

140.625

> (time(dotimes (zCount 10000)(set(sym(string "TEST" zCount))10)(set(sym(string "TEST" zCount))nil)))

218.75

> (time(dotimes (zCount 10000)(set(sym(string "TEST" zCount))10)(delete(sym(string "TEST" zCount)))))

1046.875

Deleting the symbol seems to need more performance. But memory?



Hans-Peter

[Lutz]

Deleting a symbol affects the symbol-tree and a check for reference from resident code or data is made. The memory usage of a symbol is very little with 28 bytes plus the name string on 32bit newLISP on Windows.