Re: Ada & PDL (ick !)

[alex@MIMSY.CS.UMD.EDU (Alex Blakemore)]

In article <1992Dec10.200346.1406@den.mmc.com> heck@hercules.den.mmc.com writes
:

> I have found Ada PDL is a good design tool

I second that - along with a *few* key pictures (not necessarily bubbles) 

Ada as PDL also supports iterative development, forming contracts between devel
opers
early (based on commented specs). It takes some discipline to resist the urge 
to march right into some interesting routine while leaving the big picture half
 baked,
but thats true with PDL in general.

DEC supports a mode on their compiler (/DESIGN I think) that just does front en
d checking
and relaxes some Ada rules - specifically for supporting PDL.  For example, you
 can
have LSE tokens and placeholders in the file, dont have to bother supplying
private parts and a few other niceties.  This way you can quickly check your de
sign
level specs for consistency without having to fill in all the details to get pa
st
the compiler.  Then just dont use the design compiler option when you're ready 
to
get serious.

One last DEC ad, they were demoing some really great compiler advances at TriAd
a -
smart recompilation so that if you only change one procedure (say) in a package
spec, then only the units that actually reference that procedure have to be rec
ompiled.
all the other units that depend on the revised package are just magically broug
ht up to date.
This could be a real boon to large system development.  They said it would be i
n the
next version. (I know Rational does similar things, but many dont have access o
ne)
-- 
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Alex Blakemore alex@cs.umd.edu   NeXT mail accepted