I need a little help - it's been a long time - with enumeration type and for use representation

[Harry Tucker <harry.tucker@sbcglobal.net>]

I haven't played with Ada for many years. I've read John Barnes' book,
Programming in Ada 2005, and picked through the ARM on my problem.

I have a piece of data which represents a enumeration as a hexadecimal
value. It is a bit field but I see the data most usefull as an
enumeration. for example in the CSV file the data is represented as
'0x1'. So I defined the enum as:

<code>
   type Spell_School_Type is (
      UNKNOWN,
      PHYSICAL,
      HOLY,
      FIRE,
    ...
</code>

And since the data has a value I use a represetation clause as:
<code>
   for Spell_School_Type use
     (UNKNOWN     => 2#0000_0000#,
      PHYSICAL      => 2#0000_0001#,
      HOLY             => 2#0000_0010#,
      FIRE              => 2#0000_0100#,
    ...
</code>

Is the best way to parse the raw info (i.e. 0x1)  into the enumeration
(i.e PHYSICAL) to use a if/elsif and assign the enum position or is
there an attribute which works best.

Harry