Re: Qu: 3D unconstrained arrays

[kdm@rational.com (Kent Mitchell)]

Randy Binnie (randyb@ssd.fsi.com) wrote:

: Hi,  Assuming this news group allows non political postings, I have an
: Ada implementation question???
We always accept non-political postings.  In fact we prefer them but some
times ....

: How can one create a 3 dimensional unconstrained array  made up of a one
: dimensional  unconstrained array  and a two dimensional unconstrained array.
: Ideally I would like to do the following, but it is not allowed because the
: type  ARRAY_2D_TYPE  is unconstrained.

:   type ARRAY_2D_TYPE  is array ( range <>, range <>)  of DATA_TYPE;
:   type ARRAY_3D_TYPE  is array ( range <>)  of  ARRAY_2D_TYPE;
This exact structure is not possible so you can't create what you describe
above (a two dimensional unconstrained array containing a one dimensional
unconstrained array).  However, see below to create what you want as you
cleaner solution.

: but I would prefer a cleaner solution using a single monolithic 3 dimensional 
: data structure.  So my question is can it be done, if so a brief explaination 
: would be appreciated.  This is for an Ada '83 compiler.

A monolithic 3d array is declared as:

    type Array_3D_Type is
      array (Positive range <>, Positive range <>, Positive range <>)
      of Data_Type;

Note: I had to add a type for the range <>.  I picked positive but any
discrete type will do.
--
Kent Mitchell                   | One possible reason that things aren't
Technical Consultant            | going according to plan is .....
Rational Software Corporation   | that there never *was* a plan!