[lnkForumImage]
TotalShareware - Download Free Software
Confronta i prezzi di migliaia di prodotti.
Asp Forum
 Home | Login | Register | Search 


 

Forums >

comp.lang.ruby

storing boolean flags in numbers

Sebastian probst Eide

5/23/2007 10:43:00 AM

I might sound completely dumb asking this question, but well, I'll risk
it anyway!

Some years ago I read about using a single number as a mechanism for
storing flags (on/off values) in a Java magazine.

By setting the bits in a number to either 0 or 1 you could store
enormous amounts of boolean values in a single number.

An example.

I have three flags:
Flag1
Flag2
Flag3

(The following byte sequences are written from the right)

Flag1 = true
Flag2 = false
Flag3 = false
gives:
001 => 1

Flag1 = false
Flag2 = true
Flag3 = true
gives:
110 => 6

Flag1 = true
Flag2 = false
Flag3 = true
gives:
101 => 5

In the magazine they used some sort of combination of AND and OR and XOR
and stuff like that to get the different values.
Would there be an easy way to do this in Ruby? How would one implement a
thing like this?
I basically just need a way to read the different values. I'll try to
extend it myself so I can read any given number of flags myself. Just
need to understand how to read and set the flags!

Best regards
Sebastian

--
Posted via http://www.ruby-....