Path: utzoo!utgpu!watmath!clyde!att!westmark!mole-end!mat
From: mat@mole-end.UUCP (Mark A Terribile)
Newsgroups: comp.lang.c
Subject: Re: Proposal for a scientific look at C style choices
Summary: Another edge on the style graph ... and why
Message-ID: <132@mole-end.UUCP>
Date: 27 Dec 88 02:49:29 GMT
References: <eWl9H#2cdgbS=eric@snark.UUCP>
Organization: mole-end--private system.  admin: mole-end!newtnews
Lines: 54

> C code layout is a classic example of rule-governed behavior in which the
> rules are inexplicit and often less than half-conscious, but evidently very
> strong.

> [I'd like to] work out ... a decision tree or graph that has coders' value
> choices about various aesthetic issues as arcs and various described coding
> styles or coding style classes as nodes -- a ... functional taxonomy ....

<switch() statement layout examples>

> Now, I *think* that the "comb" versus "block" choice hangs on a question
> that goes something like this:
> 
> Question S: are you willing to make an exception to the global rule that the
> contents of a control block is indented one level deeper than the "sentinel"
> part in order to make switches look more like jump tables, or to reduce their
> cost in visual nesting depth?

I will offer another decision that must be made: is the ``sentinel'' part
a monolith, or does it have multiple levels as well?

I indent the case labels by two spaces on the belief that they are easier to
see that way (I use 8-space indents) and on the belief that the control
(sentinel) is not a monolith.  Likewise, I generally write

	if(    a->op == XNES_step
	    && a->size <= XNES_bufsize
	 ||    a->op == XNES_fix
	    && a->size + a->leftover <= XNES_bufsize )
	{
		. . .
 
> If I'm right, this is one node in the ur-graph of C styles I'm after. The
> interesting question: are there other, *fundamentally different* criteria on
> which this choice can be made? If so, what are they? 

Visual presentation, for one.  I like to be able to look at a piece of code
three feet away and know where the different chunks of code begin and end,
and upon which ``splinters'' the various chunks depend.  (I'm a charter member
of The Committe to Keep Whitespace White :^> )

Oh, and I prefer to see my text printed in portrait mode using a fixed-width
``typewriter'' font by a high-res (laser or electrostatic) printer.

> Question B: in control structures, do you consider the braces to be more
> firmly glued to a) the "guard" part, or b) the enclosed statement(s).

Neither.  They are an adapter between the ``guard'' which controls single
statements and the group of statements which often need to be controlled
together.
-- 

(This man's opinions are his own.)
From mole-end				Mark Terribile