On 3 May 2010, at 19:34, Jorden M wrote:
On Mon, May 3, 2010 at 10:53 AM, erik quanstrom
<[email protected]> wrote:
It's always been easier for me to use python's/perl's regular
expressions when I needed to process a text file than to use
plan9's.
For simple things, e.g. while editing an ordinary text in acme/sam,
plan9's regexps are just fine.
i find it hard to think of cases where i would need
such sophistication and where tokenization or
tokenization plus parsing wouldn't be a better idea.
A lot of the `sophisticated' Perl I've seen uses some horrible regexes
when really the job would have been done better and faster by a
simple, job-specific parser.
I've yet to find out why this happens so much, but I think I can
narrow it to a combination of ignorance, laziness, and perhaps that
all-too-frequent assumption `oh, I can do this in 10 lines with perl!'
I guess by the time you've written half a parser in line noise, it's
too late to quit while you're behind.
I think it's ignorance and something. I'm not sure what that something
is. I am sure if you tried to suggest writing a parser to many of the
open-sourcers I've talked to you would be treated as if you were
suggesting a big job rather than a small one. "Why Write a Parser,"
they would ask, "when I can just scribble a few little lines of perl?"
Maybe it's humans' natural tendencies toward hierarchy coming into
play. Stuff known by Teachers and Masters easily takes on a bizarre
kind of importance, rank is unconsciously attached, and the student
naturally but unconsciously feels he is not of sufficient rank to
attempt the Master's Way. That explanation does pre-suppose humans
have a very strong natural tendency to hierarchy. I find sufficient
evidence within myself to believe it's true, as unpopular as the idea
may be. Perhaps some people are more strongly inclined that way than
others. Anyway, it's the only explanation I can imagine for the
phenomena.
for example, you could write a re to parse the output
of ls -l and or ps. but awk '{print $field}' is so much
easier to write and read.
so in all, i view perl "regular" expressions as a tough sell.
i think they're harder to write, harder to read, require more
and more unstable code, and slower.
one could speculate that perl, by encouraging a
monolithic, rather than tools-based approach;
and cleverness over clarity made perl expressions
the logical next step. if so, i question the assumptions.
- erik
--
Simplicity does not precede complexity, but follows it. -- Alan Perlis
