On 01/14/12 19:54, Robert Bonomi wrote:
From owner-freebsd-questi...@freebsd.org Sat Jan 14 02:32:15 2012
Date: Sat, 14 Jan 2012 09:28:21 +0100
From: Polytropon<free...@edvax.de>
To: Robert Bonomi<bon...@mail.r-bonomi.com>
Cc: freebsd-questions@freebsd.org
Subject: Re: access(FULLPATH, xxx);
On Sat, 14 Jan 2012 02:00:12 -0600 (CST), Robert Bonomi wrote:
To repeat some advice from one of my Computer Science professors, many years
ago, whenever I asked 'how does it work' questions: "Try it and find out."
I bet my professor can beat up your professor. :-)
Mine used to say several times: "Trial and error is NOT
a programming concept!"
As far as writing applications goes, that is _somewhat_ correct.
However, 'trial and error' is _not_ the same thing as 'try it and find out'.
See the entire subject area of 'benchmarking'.
And, the only way to definitively establish if an alternate approach is
'better' -- i.e. 'faster', or 'smaller', or 'more efficient', etc. -- *IS*
to run a trial.
Your professor undoubtedly would not of approved when I wrote bubble-sort
code that _out-performed_ any other sorting technique -- up to the limits
of memory. Or when I re-wrote an application that used binary searches
of records, with a new version that used a brute-force linear search. I
thought I could 'do it better/faster' than the existing code, but the only
way to "definitively" find out was to 'try it'. And the 'trial' proved
out -- the replacement code was 'merely' somewhat over 100 times faster.
*grin*
Ha! Love it... :D
As far as 'doing it once' for the purpose of answering a 'how does it work'
question -- where one has _not_ read the documentation, *OR* the existing
documentation is _not_clear_, then simple experimentation -- to get *the*
authoritative answer -- is entirly justified.
When I got the 'try it and find out' advice, I was asking questions about
situations where the language _specification_ was unclear -- there were
two 'reasonable interpretations' of what the language inthe speciication
said, and I just wanted to know which one was the proper interpretation.
Now, given that the language in the specification _was_ abiguous and both
interpretations were reasonsble, different compiler builders could have
implemented differently, and 'try it and find out' was _necessary_ to
establish what that particular implementation did.<grin>
There appears to be 2 schools of thought on this subject: a classic case
of the "old" vs the "new", in this case "punchcards/slow compilers" vs
"gcc/all-in-one compile, link and go"of todays tech. I saw a similar
conversation about 5 years ago on the linux lists... :)
Technically (depending on their era) they're both right. For reference
as far as the linux lists played out no one won the argument, but it was
a helluva nostalgic/historical debate!
In the light of this conversation and given todays tech I'd say give it
a shot unless you think something could break (as in fatal to service
quality in production/hardware).
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