Re: Source code formatting: line length limit?

["Robert J. Chassell" <bob@rattlesnake.com>]

I wrote:

   > ....  A fill-column of 70 works well with the usual
   > between-line spacing on a computer screen.

"Stefan Monnier" <monnier+gnu/emacs@rum.cs.yale.edu> responds

   Note that in source code, most lines don't start in column 0, so for
   a given line, the number of columns of text is not necessarily the same
   as the column of the rightmost char.

   I happen to think that 60 columns is more legible,  ...

Yes.  In some ways, 60 is better; it is even harder to swing your eyes
down when the lines do not start in the left most column.

However, one advantage of a wider line is that more information is put
on the line.  Programming expressions are ways of stating complex
notions in a manner than a human can comprehend.  It is easier to
understand and bear in mind a notion laid out in one line than spread
out over two or three.  A key characteristic of programming languages
designed for programmers, such as C or Lisp, is that they are
succinct.

On the other hand, excessive width does reduce the compactness of a
notation as much as excessive depth, so a line cannot be overly long.

(Excessive succinctness creates another problem; many programmers find
it hard to comprehend a expression that is `too concise', for some
fuzzy definition of `too concise'.  A popular programming language
must be a balance between `too concise' and `too wordy'.)

   .... but I also think that in most cases, source code that spans 80
   columns is perfectly legible because almost none of the lines
   actually takes more than 60 columns of text.
   ... 
   Also the non-constant indentation of the code also helps
   your eyes find the next line.

Indentation helps, but large areas of blank space on the left give
difficulty to me nonetheless.

   And since I find vertical screen-real-estate to be at a premium, I advocate
   using all 80 columns for code (text is obviously another matter).

An 80 column text looks terrible when patched or quoted so as to be
wider, but still shown on an 80 column window.  Consequently, an 80
column width will discourage some from quoting or patching your code,
since he or she will have to pretty print it before working on it.

-- 
    Robert J. Chassell                         Rattlesnake Enterprises
    http://www.rattlesnake.com                  GnuPG Key ID: 004B4AC8
    http://www.teak.cc                                     bob@gnu.org