Some ada design questions...

Some ada design questions...

[David Morton]

I posted a little on this some time ago, but the debate fizzled.

I'm trying to write a simple (??) database program to 
help me with Ada programming (and to provide my sys-admin with a simple 
program to maintain user info with).  

I'm having difficulty in designing this right now.

My plan has been:

a File_Io package that uses direct_IO.  This requires a definate
  size data record. ie, a record type containing all the data.
a screen_Io package that is capable of getting immediate keyboard
  access and doing ncurses-like screen manipulation (This part I can do already)
a management package to coordinat the various actions depending on input from
  the screen_io package
all of which uses the record layout info contained in user_info_stuff


The problem is that the screen package needs more info than the
record provides.  I was planning to make a linked list that contained all the necessary
info(Screen coordinates, the buffer for input, whether the current highlighted 
     object is a button or field...)
Does this mean that the management package needs to copy the buffer info
into the appropriate record buffer to pass to file_Io???
I was hoping to have an access variable in the linked list that points to the
record buffer, but the compiler complains unless I use unchecked_access.
furthermore, type string_Ptr is access string;  doesn't point to 
just *any* size string.
but I need an access variable to different size buffers, depending on 
which node of the list I'm pointing at. Is there any way to do that, or do I need to
simply convert the data at the management package level?          

I hope this makes sense, I'm starting to confuse myself.

-- 
David Morton
 mailto:dmorton@jinx.sckans.edu    // If you use Netscape 2.0,
 205 College, Winfield, KS 67156   // you can click on the mailto: part to reply!
                                   (HINT, HINT)  :)