Re: ada without ada libraries?

[Simon Wright <simon@pushface.org>]

Patrick <patrick@spellingbeewinnars.org> writes:

> I just got my compiler set up the way I want it and I am ready for my
> first ada project.
>
> I have spent sometime with lua. Lua's library support is terrible but
> lots of people love the language. Many people just build a rough
> skeleton application in C and call it from lua.
>
> Lua handles all the type checking and much of the logic in this
> arrangement and C is mostly just library code.
>
> Would this same approach seem logical for ada? -Patrick

It doesn't really seem logical for C! Perhaps I've misunderstood you.

I don't know Lua, but I do know Tcl, and the approach I've adopted is to
write the application engine, if you will, in Ada and the controls in
Tcl. The application engine can be very complicated, but the controls
are usually simple.

An example: this proc runs every 100 ms to see whether each of 4 lamps
should be lit or not. The Ada part of the app presents the function
getLampState which takes a string (the name of the lamp) and returns a
boolean (0 or 1, I expect) saying whether it should be lit. The GUI is
written in Tcl[/Tk], which it's good at, and the complex timing logic
about when the lamps should be lit is left to the Ada.

   proc checkLampProc {} {
       foreach l {a b c d} {
           set s [getLampState $l]
           if {$s} {
               .c itemconfigure $l -fill yellow
           } else {
               .c itemconfigure $l -fill gray
           }
       }
       after 100 checkLampProc
   }