ISO Studies of underscores vs MixedCase in Ada or C++

[Andy Glew]

I am in search of any rigourous,
scientific, academic or industrial studies
comparing naming conventions in
C++ or similar languages such as
Ada:

Specifically, are names formed with
underscores more or less readable
than names formed with MixedCase
StudlyCaps camelCase?

....and similarly, any measurements
of programmer productivity, bug rate,
etc.; although IMHO readability matters
most.
* Religion - NOT?!

I understand that this is a religious issue
for many programmers, an issue of programming style.
I am not interested in a religious war.
I obviously have my own opinion, but I am
open to scientific evidence.
* Ada Studies?

I thought that I had seen studies like
this in some of the early design documents
for Ada, but I have not been able to find
such references on the web. Which is not
entirely surprising, since Ada was designed
prior to the web.

The Ada 83 and 95 Quality Guidelines recommend
underscores to improve readability, but provide
no source justifying this statement.
* What such studies might look like

Simple readability and recall:
- present a test subject with
a list of compound words
formed with underscoresand mixed case
- remove the list, and ask test subject
to write it
- score on accuracy

Program debugging
- present programs that are otherwise identical,
differing only in their use of underscores/MixedCase
to test subject programmers (e.g. a CS class)
- program has a known bug
- ask test subjects to find bug
- score on accuracy locating bug

Cruel TA study:
- Two sections of a CS class
- Enforce programming standards,
underscores vs MixedCase
- Pose a programming problem
- Score according to success
completing assignment

Empirical:
- Given version control databases
of large programs, some written in underscore
style, others in MixedCase
- Total bug rates normalized by LOC, name count, etc.
- OR: count only bugs that can be attributed
(after inspection of checkins) to misnamed variables

For that matter, I would be interested in any surveys
folks may have done that count projects and their
coding standards, possibly weighted
- open source (e.g. sourceforge)
- industrial
- textbooks, weighted by sales
- websites of coding standards, weighted by Google score...
Although this is less convincing than a rigorous study.
* Explanation of Newsgroups Chosen

I hope it is obvious why I have chosen these
newsgroups to post this search to:

comp.software-eng, comp.programmin g,
- an issue of software engineering
comp.lang.c++,
- the language I am most interested in
comp.lang.ada
- because I vaguely recall historical work

[Wes Groleau]

Jacob Sparre Andersen wrote:

James Dow Allen wrote:

abbreviate them as the first 4 (or whatever) letters, consistently.

So Bandshift should be abbreviated Band ?

Megahertz should be Mega, not MHz ?

Message should be Mess, not Msg ?
I prefer the suggestion from the Ada style guide (IIRC) that you don't
abbreviate words, and that you only use acronyms from a limited
project-specific list.

And that list should be designed to include only
a limited number of items, using the abbreviation
that is already widely used in the problem domain.

(If no widely-used abbreviation exists, the item
should not be abbreviated.)

And the following practice is sad, but it does happen
in some places:

Problem: "Abbreviati on is not on the approved list."
Solution: "Change the list; we're building TODAY."

--
Wes Groleau

Is it an on-line compliment to call someone a Net Wit ?

[Stephen Baynes.]

"Jacob Sparre Andersen" <sp****@crs4.it > wrote in message
news:3F******** ******@crs4.it. ..

Jakob Bieling wrote:

[ abbreviated identifier prefixes ]

Not sure where I picked that habit up, but I guess it is pure laziness. I could not imagine having to type those long names everytime you use them.

Well. I tend to read code more often than I write it (even my own), and
most of my time is spent thinking about what to write, so saving a few
keystrokes really doesn't make sense to me.

Especially counter variables in for-loops (posting from comp.lang.c++)

... you also use simple i's and j's etc. there, right?

No. (unless it is for matrix and tensor manipulation, where the
"documentat ion" actually says "i", "j" and "k")

To me the length of the name should reflect the size of the scope. A one
letter variable name is fine for the counter in a very short for loop, or a
temporary that is only used for a couple of adjacent statements. But if the
variable is used over many lines a longer more meaningful name is required.
Global variables tend to end up with the longest names as they have to be
used and understood in many more contexts.

Like all rules - there are exceptions. In particular if something is used
very frequently then a shorter name is desirable for convenience and
acceptable as it will be well known and understood. [eg 'stderr']

--
Stephen Baynes CEng MBCS
My views are my own

[Gene Wirchenko]

On Fri, 03 Oct 2003 15:42:20 -0700, Peter Ammon
<pe*********@ro cketmail.com> wrote:

[snip]

Agreed! I wish that more languages allowed hyphen use in identifiers.
Dylan is the only one I can think of off the top of my head.

COBOL does.

Sincerely,

Gene Wirchenko

[Oplec]

Gene Wirchenko wrote:

On Fri, 03 Oct 2003 15:42:20 -0700, Peter Ammon
<pe*********@ro cketmail.com> wrote:

[snip]

Agreed! I wish that more languages allowed hyphen use in identifiers.
Dylan is the only one I can think of off the top of my head.

COBOL does.

Sincerely,

Gene Wirchenko

Is there a link to a document on ISO Studies of underscores... ?

Thanks, Oplec.

[Dave Vandervies]

In article <fk************ *************** *****@4ax.com>,
Gene Wirchenko <gw************ **@CAPITALSwenc omine.com> wrote:

On Fri, 03 Oct 2003 15:42:20 -0700, Peter Ammon
<pe*********@r ocketmail.com> wrote:

[snip]

Agreed! I wish that more languages allowed hyphen use in identifiers.
Dylan is the only one I can think of off the top of my head.

COBOL does.

As does Scheme, along with (if I'm not mistaken) most or all of the
other members of the Lisp family.
dave

--
Dave Vandervies dj******@csclub .uwaterloo.ca
Remember we're in a language where a misbehaving human can produce
quite a few kleenex-embedded demons.
--Chris Wolfe in comp.lang.c