Re: Is strong typing worth the cost?

[dmjones <derek@NOSPAMknosof.co.uk>]

All,

To summarise, no new research investigating the
cost/benefit of using strong typing has come to light.
There was a suggestion that a John McCormick might
be able to provide some pointers.  I have contacted him
and he does not know of any such published research.

On the basis that somebody reading this group might be
interested in carrying out some research, or perhaps funding
it (I have other fish to fry and am not after funds to do
it) lets move on.

I have tried to summarise peoples points.  Please say if
I have misrepresented you.

Jeffrey Carter:  Only recommend strong typing if evidence
in favour of it?  Otherwise recommend use of weak typing?

Me:  I am dealing with developers who use a weakly typed
language.  To change existing practice I need evidence
that it is worthwhile.  The default is weak, I am not recommending
anything unless I have evidence one way or the other.

The language is C.  So called 'safe' subsets are typically created
by removing 'dangerous' constructs.  Please don't ask me to
define a 'safe' subset, or what a 'dangerous' construct is.  I
don't know.  Anyway, my interest is more economics based, reducing
the cost of software ownership.  Rather than subseting, why not
add to the language; stronger typing is the candidate?

Yes, I know that adding stronger typing to C is not a sensible
thing to do for all sorts of reasons.  I am looking for an
incremental change in developer usage (a separate tool [modified
gcc or commercial product, the tool is not the issue] to
enforce the checks, then compile with existing compiler).  Being
evangelical about using another language is not where I am coming
from.

Marc Criley:  Can strong typing be separated from the host
language?

Me:  Probably not 100%.  Is 90% possible?  Who knows.
Experience has taught me (Pascal based commercial applications
in the 80's, accounts packages, simple process control, simple
database applications, etc), that developers can quiet easily
write code using only integer & real + arrays of those types.
It's no good turning our noses up at such code.  Unless developers
are given good training, incentives to use what they have learnt,
and time to perfect their skills, so called 'well written' code
will not get written.

I am not interested in detailed language issues.  I want a study,
with independent duplication, showing use of string typing has
a cost/benefit of X%.  Where X is suitably impressive.

Frank Bearcd, tmoran:  Safe & correct is everything.

Me:  Making a profit is everything.

Neither statement is true.  Readers will have no trouble thinking
of bug ridden products that make their owners a fortune.  I know
of products that have been shown to have a high degree of correctness
that have lost money and caused their developers to go bust.

I see strong typing as a tool for cost reduction in acheiving
a specified level of software reliability.  Nothing more.

Jim Rogers:  What are the parameters of cost?

Me:  Money.  Developers time (original development, subsequent
maintenance), lost business opportunities being late to market
(finding staff with necessary skills, additional lead time in
getting it 'more right').  Plus lots of other things.