merlyn@stonehenge.com (Randal L. Schwartz) writes:
quoted
quoted
Being as I'm a *bit* familiar with Perl, I'd write that as:
print H "$_\0" for @deletedfiles;
... It was added for Perl 5.5, first released on 22 July 1998.
BTW, I never understood the usefulness of Statement Modifiers.
Even reading the examples in perlsyn.pod:
print "Basset hounds got long ears" if length $ear >= 10;
go_outside() and play() unless $is_raining;
seeing "do these things" upfront and then realize "ah, but that
is done only when this holds true", interrupts the flow of
understanding while reading a program by somebody else [*1*].
It is worse if the Statement Modifier is a loop control.
(flamebait) Compound Statements take BLOCK and people who want
to do a one-liner could not do so without braces. I've always
thought Statement Modifies as a lame workaround for that
problem.
[Footnote]
*1* This is true even for me; my mother language is Japanese,
which tends to hang negation at the tail of the sentence, and
double negation is not unusual. This makes it impossible to
know what a sentence states before reading it to the end, so I
am used to that "coming back to the main part after reading
through the sentence", but I do not welcome that when I am
reading programs.
Junio C Hamano wrote:
BTW, I never understood the usefulness of Statement Modifiers.
Even reading the examples in perlsyn.pod:
print "Basset hounds got long ears" if length $ear >= 10;
go_outside() and play() unless $is_raining;
seeing "do these things" upfront and then realize "ah, but that
is done only when this holds true", interrupts the flow of
understanding while reading a program by somebody else [*1*].
Here's what "Programming Perl" by O'Reilly (third edition, somewhere
around page 604) has to say about it:
---%<---%<---%<---
*) Do things the most readable way. For instance:
open(FOO, $foo) or die "Can't open $foo: $!";
is better than
die "Can't open $foo: $!" unless open(FOO, $foo);
because the second way hides the main point of the statement in a modifier.
---%<---%<---%<---
Considering the book was co-authored by Larry Wall, I'd say that's as
good as an apology.
It is worse if the Statement Modifier is a loop control.
(flamebait) Compound Statements take BLOCK and people who want
to do a one-liner could not do so without braces. I've always
thought Statement Modifies as a lame workaround for that
problem.
Most things can be done without braces, so long as one doesn't spell out
the 'if'.
$opt_h and usage();
-d $directory or mkdir($directory);
is perfectly valid perl. This way of writing it is familiar enough for
shell-scripters. Hardcore C-programmers will look twice when they see a
line that so obviously looks completely wrong and will almost certainly,
with some revulsion, understand it.
--
Andreas Ericsson andreas.ericsson@op5.se
OP5 AB www.op5.se
Tel: +46 8-230225 Fax: +46 8-230231