Does Python really follow its philosophy of "Readability counts"?

[Paul Rubin]

James Mills <prologic at shortcircuit.net.au> writes:
> > "Today, Boeing uses about 500,000 lines of Ada to fly its commercial
> > 747 400 in subsystem components, critical certification, and human
> > safety features. Two of the three largest systems on the 747, or 43
> > percent of the executable bytes, are written in Ada. The software is
> > FAA certified."  (http://archive.adaic.com/docs/flyers/commapps.html)
> 
> You wouldn't happen to have a source for this information would you ?

Just the url that is there.

> And this (if true) hardly suprises me as Ada is one of the most
> rigorous and strictest languages I have ever used.

I have no direct experience with it but have read a little about it.
It looks to be a fairly vanilla block structured imperative language
like Pascal with some concurrency stuff added.  The sense I have is
that it's not especially harder to program in than C or C++, but the
programs come out much more reliable.

If you want to see something really rigorous and strict, take a look
at ATS: http://ats-lang.org .  Here is a certified quicksort in ATS:

  http://www.ats-lang.org/EXAMPLE/MISC/listquicksort.dats

The point is that ATS's type system is powerful enough to define a
type for a sorting routine (a function that takes a list as input and
produces a sorted permutation of the input list).  If you then write
something that purports to be a sorting routine but fails to produce a
sorted permutation, the compiler will reject the program with a type
error.  If your routine compiles at all, it sorts correctly.