karl@haddock.ima.isc.com (Karl Heuer) (10/19/90)
Style wars beginning. Hit 'n' now. In article <1990Oct15.042851.18595@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <3343@idunno.Princeton.EDU> pfalstad@drops.Princeton.EDU (Paul John Falstad) writes: >> while(...); > >By the way, tacking the ";" on the end of the while is a great way to >trip up your readers... This is a valid concern. On the other hand, there are those of us who gag at the sight of a naked semicolon on a line by itself, which is what I guess Henry to be suggesting as an alternative. Some time ago I adopted the convention of writing bodyless loops as do; while (...); so that it's impossible to accidentally leave out the final semicolon. This produced an immediate bonus in that it often revealed a further transformation that simplified the code: while ((rpid = wait(&status)) != pid); ==> do; while ((rpid = wait(&status)) != pid); ==> do rpid = wait(&status); while (rpid != pid); The use of an assignment as a subexpression of a condition is only necessary for test-at-top loops; thinking of it as a test-at-bottom loop eliminates the need. (This assumes that, all else being equal, "a=b; if (P(a))" is better than "if (P(a=b))". That leads back to the ":= vs = vs ==" wars, which should probably go to comp.lang.misc.) Exercise: evaluate each of the forms below (insert newlines according to your personal style) and rank them according to susceptibility to disastrous typo and/or reader misunderstanding. Send your results by USmail to the person whose name is immediately under yours in the Phone book. while (...); while (...) /* nothing */; while (...) {} while (...) continue; do; while (...); do /* nothing */; while (...); Karl W. Z. Heuer (karl@ima.isc.com or uunet!ima!karl), The Walking Lint
henry@zoo.toronto.edu (Henry Spencer) (10/19/90)
In article <18573@haddock.ima.isc.com> karl@ima.isc.com (Karl Heuer) writes: >>By the way, tacking the ";" on the end of the while is a great way to >>trip up your readers... > >This is a valid concern. On the other hand, there are those of us who gag at >the sight of a naked semicolon on a line by itself, which is what I guess >Henry to be suggesting as an alternative. Actually, no, my preferred alternative is while (...) continue; although I can live with minor variants like using {} instead of continue. (This is, incidentally, just about the only use of continue that I'm happy with!) -- The type syntax for C is essentially | Henry Spencer at U of Toronto Zoology unparsable. --Rob Pike | henry@zoo.toronto.edu utzoo!henry
jh4o+@andrew.cmu.edu (Jeffrey T. Hutzelman) (10/20/90)
how about these:
#define ever (;;)
#define nothing ;
Then you get
for ever
{
...
}
and
do nothing while (...);
-----------------
Jeffrey Hutzelman
America Online: JeffreyH11
Internet/BITNET:jh4o+@andrew.cmu.edu, jhutz@drycas.club.cc.cmu.edu,
jh4o@cmuccvma
>> Apple // Forever!!! <<floyd@hayes.ims.alaska.edu (Floyd Davidson) (10/20/90)
In article <kb7nFyq00Vp5QS7UVi@andrew.cmu.edu> jh4o+@andrew.cmu.edu (Jeffrey T. Hutzelman) writes: >how about these: > >#define ever (;;) >#define nothing ; > >Then you get > >for ever > { > ... > } > >and > >do nothing while (...); >----------------- >Jeffrey Hutzelman >America Online: JeffreyH11 >Internet/BITNET:jh4o+@andrew.cmu.edu, jhutz@drycas.club.cc.cmu.edu, > jh4o@cmuccvma > >>> Apple // Forever!!! << I looked back about 50-100 articles trying to see if this was supposed to be funny, or if you meant it. I couldn't find anything that gave me a clue. Do you actually put that in program code? -- Floyd L. Davidson floyd@hayes.ims.alaska.edu 8347 Richardson Hwy. floydd@chinet.chi.il.us Salcha, AK 99714 [and related to Alascom, Inc. by a pay check, only]
daveg@near.cs.caltech.edu (Dave Gillespie) (10/22/90)
>>>>> On 19 Oct 90 15:50:17 GMT, henry@zoo.toronto.edu (Henry Spencer) said: > In article <18573@haddock.ima.isc.com> karl@ima.isc.com (Karl Heuer) writes: >>By the way, tacking the ";" on the end of the while is a great way to >>trip up your readers... > > Actually, no, my preferred alternative is > while (...) > continue; My favorite way is to write while (...) ; wish a space before the trailing semicolon. It's concise, and unambigious (to me at least) because I never put a space before the semicolon for any other reason. (Nor do most C programmers I've seen.) -- Dave -- Dave Gillespie 256-80 Caltech Pasadena CA USA 91125 daveg@csvax.cs.caltech.edu, ...!cit-vax!daveg