Re: scripting/extension language for Ada (was : Re: tagged types extensions)

[Lionel Draghi <Lionel.Draghi@free.fr>]

"Samuel T. Harris" wrote:
> 
...
> My feelings exactly
> 
> I remember working on the good old Rational R1000 in the Air Force
> and for Link then Hughes now Raytheon. The entire operating system
> interface was in Ada with the speed of execution of an interpreter.
> I was impressed how the total immersion into Ada for the most
> basic user needs rapidly increased new programmer capabilties
> in the language. I suppose that is supported by the notion that
> one learns French much faster by living in France as compared
> to taking college courses.
> 
> I have toyed with Ada/Ed as an script interpreter but its
> requirements to pre-analyze the code does not make it a viable
> candidate for shell-script replacements. Its just not fast
> enough.
> 
> It occurs to me that an Ada interpreter can dispense with
> many of the compile-time checks, relying instead upon a real
> compiler to "verify" the script source is correct Ada.
> This alone would enable an interpreter to simply expand
> generics like macros and not bother with all the checks
> concerning the instantiation.
This is a good idea. But i am not optimist enough to think that even Ada
run time checks could be enforced in a reasonably sized interpreter. But
this is the goal.
Another question is : should this script language be strictly compatible
with Ada? Isn't there any short form that could be effective, and that
prevent from direct recompilation with an Ada compiler?
For example, it could make sense to consider Ada.Text_IO, or a Pattern
Matching package implicitly "whithed" (and maybe even "used"!). 
> 
> If I recall correctly, the old Ada-Sage (now Sage-ST) did
> include a very limited Ada interpreter. This allowed one
> to quickly prototype the database interface with simple
> controlling code with very rapid turn-around. Just the
> sort of thing one needs with hashing out the user
> interface on-line with the customer.
Is it available?

________________________________________________________________________
Lionel Draghi                                          http://attac.org/