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140 lines
3.9 KiB
Plaintext
140 lines
3.9 KiB
Plaintext
Coding Style for PLIF
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---------------------
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This style guide is designed to make sure that the code is consistent
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throughout. It isn't necessarily the best way of writing Perl, but it
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is consistent. Consistency is more important than using your preferred
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method. Please follow the style guide.
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Note: Exceptions will be accepted if they improve performance, but
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only if they are well commented.
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1. Brackets are preferred to other punctuation
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return ($a eq 'a' or $b); # preferred
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return $a eq 'a' || $b;
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2. Use brackets around all function arguments
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push(@list, $item); # preferred
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push @list, $item;
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foreach $item (sort(keys(%{$self->list}))) { } # preferred
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foreach $item (sort keys %{$self->list}) { }
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3. When calling a method for its side-effect, always use brackets
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$self->go(); # preferred
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$self->go;
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4. When calling a method as if it was a property, omit brackets
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return $self->name; # preferred;
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return $self->name();
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5. Don't use print(), use dump()
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$self->dump(9, "foo called with bar $bar"); # preferred
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print("foo called with bar $bar\n");
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6. To set a property, use the method call notation
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$self->name('foo'); # preferred
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$self->{'name'} = 'foo';
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7. method and property names should start lowercase and have a capital
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letter for each word
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sub myLovelyMethod { ... } # preferred
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sub MyLovelyMethod { ... } # bad (first letter not lowercase)
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sub mylovelymethod { ... } # bad (intervening words not capitalized)
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sub my_lovely_method { ... } # bad (underscores)
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8. methods should start with setting $self and taking their arguments
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sub myLovelyMethod {
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my $self = shift;
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my($argument) = @_;
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# code...
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}
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9. Curly brackets should cuddle
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if ($condition) {
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# do something
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} else {
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# do something else
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}
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10. Comments should be indented just like code
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if ($condition) {
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# preferred
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} else {
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# bad
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}
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11. Avoid using the implicit $_ variable
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foreach my $item (@list) { $item++; } # preferred
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foreach (@list) { $_++; }
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12. Thou shalt avoid using useful functions (which break Win32):
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alarm, chroot, crypt, endgrent, endhostent, endnetent,
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endprotoent, endpwent, endservent, fork, getgrent, getgrgid,
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getgrnam, getnetbyaddr, getnetbyname, getnetent, getpgrp,
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getppid, getpriority, getprotoent, getpwent, getpwnam, getpwuid,
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getservent, link, msgctl, msgget, msgrcv, msgsnd, semctl, semget,
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semop, setgrent, sethostent, setnetent, setpgrp, setpriority,
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setprotoent, setpwent, setservent, shmctl, shmget, shmread,
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shmwrite, socketpair, symlink, syscall
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http://ftp.univie.ac.at/packages/perl/ports/nt/FAQ/perlwin32faq5.html
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13. When creating a new dependency, make sure you mark it with the
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magic string 'DEPENDENCY', as in:
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sub init {
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my $self = shift;
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my($app) = @_;
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$self->SUPER::init(@_);
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require Some::Module; import Some::Module; # DEPENDENCY
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}
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This allows for an easy listing of each dependency using 'find'
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and 'grep'. Note also the way that dependencies are generally
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imported inside service constructors and imported using 'require'
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and 'import' instead of 'use'. This is to make sure that the
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overhead of importing the relevant code is not hit unless the
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module is used. Please make sure that 'import' doesn't end up
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being called more than once, of course.
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14. The order for declaring methods should be something along the
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lines of first class methods, then the constructor (in PLIF this
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is 'init'), then the methods you are overriding, then the new
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methods, then the destructor ('DESTROY'). This isn't cast in stone
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though. Whatever works best.
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Further notes:
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You'll notice PLIF doesn't use prototypes. This is because Perl
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doesn't support prototypes for method calls.
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- end -
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