RE: 3-bit array porting problem from ADA83 to GreenHills ADA95

[Robert Dewar <robert_dewar@my-deja.com>]

In article <NBBBJNOMKDIAJALCEFIJIEBJDGAA.rleif@rleif.com>,
  comp.lang.ada@ada.eu.org wrote:
> From: Bob Leif
> To: Darrell Higgins et al.
>
> Your 3 bit arrays may be applicable to the Human Genome
> project. They should be a good way to compress the data. It
> may also be possible to look for matching "strings".

This seems unlikely. There is a VERY significant time penalty
for using 3-bit packing instead of 4-bit packing. Unless storage
is VERY tight, and you really don't care about processing time
at all, you do better to specify 4-bit packing which is quite
efficient (since everything can be done with shift and masking
operations).

Usually the only time you want to use odd inefficient component
sizes like this is when you have external data that is formatted
in this manner.

> Would the
> inclusion of generic characters in Ada.Strings.Bounded have
> facilitated your work?

Not clear what this has to do with the subject of 3-bit
packed arrays???


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