Well, some would say it makes for a cleaner interface. Compare it to Java, which forces you to use it by often having nothing but throw/catch for errors. (For sockets, for example.) It can condense a long list of
into its raw fundamentals of
It also lets you defer errors, so something else besides your code can catch them. And it gives your code a way to describe all known errors, not just the ones you have a handy return code for. It's harder to paint yourself into a corner.
I'm just playing devil's advocate though... At best it converts if(statement) else if(statement2) into try { statement } catch { ... } try {statement2 } catch { ... } which is actually messier... At worst, try/catch amounts to a blind, targetless goto carrying a blind, typeless error code; as bad as or worse than the worst excesses of the old-fashioned spaghetti programming C++ is supposedly designed to avoid.
Hello
to help me with my studying of unix/linux outside of work I was thinking of installing Linux at home aswell as using Windows XP.
Im pretty new to Linux and Unix, could someone tell me the possible benifits or even negatives of running Linux at home as an opperating system as opposed to... (2 Replies)
What are the advantages of putting users into groups? I understand that in a corporate environment, you should create a group for each department. ie: putting finance employees into a finance group.
But are there any system advantages for doing that? How would it make it easier on the system... (3 Replies)
What is the advantages of Perl in Unix environnement.
Is it for scripts ? Text manipulation ?
Have you a Concrete exemple of perl utilisation.
Thanks you (3 Replies)
Hi,
I have this script:
awk -v va=45 '$0~va{print}' flo2
That returns: "4526745 1234 " (this is the only line of the file "flo2".
However, I would like to get "va" to match the begining of the line, so that is "va" is different than 45 (eg. 67, 12 ...) I would not have any output. That... (3 Replies)
Hi,
I need to compare file names in a folder with several strings(which are in regular expression format):
For example:
there is a file "objectMyHistoryBook" and there are several strings to compare this file name with:
objectMyMaths*, objectMyEnglish*, objectMyHistory*,... (2 Replies)
Readers,
Reading a previous post about comparing files using awk ('awk-compare-2-columns-2-files-output-whole-line', https://www.unix.com/shell-programming-scripting/168432-awk-compare-2-columns-2-files-output-whole-line.html), it is possible to adjust this, so that regular expression can be used... (8 Replies)
Discussion started by: linuxr
8 Replies
LEARN ABOUT DEBIAN
dancer::exception::base
Dancer::Exception::Base(3pm) User Contributed Perl Documentation Dancer::Exception::Base(3pm)NAME
Dancer::Exception::Base - the base class of all Dancer exceptions
DESCRIPTION
Dancer::Exception::Base is the base class of all Dancer exception. All core exceptions, and all custom exception registered using
"Dancer::Exception::register_exception" inherits of "Dancer::Exception::Base".
METHODS
throw
Throws an exception. It's what "raise" (from Dancer::Exception) uses. Any arguments is set as raising parameters. You should not use this
method directly, but instead, use "raise" from Dancer::Exception.
Warning, if you want to rethrow an exception, use "rethrow".
rethrow
Re-throw the exception, without touching its parameters. Useful if you've caught and exception but don't want to handle it, and want to
rethrow it.
try { ... }
catch {
my ($e) = @_;
$e->does('InvalidLogin')
or $e->rethrow;
...
};
does
Given an exception type, returns true if the exception is of the same type.
try { raise InvalidLogin => 'foo'; }
catch {
my ($e) = @_;
$e->does('InvalidLogin') # true
...
};
It can receive more than one type, useful for composed exception, or checking multiple types at once. "does" performs a logical OR between
them:
try { raise InvalidPassword => 'foo'; }
catch {
my ($e) = @_;
$e->does('InvalidLogin', 'InvalidPassword') # true
...
};
get_composition
Returns the composed types of an exception. As every exception inherits of Dancer::Exception::Base, the returned list contains at least
'Base', and the exception class name.
Warning, the result is a list, so you should call this method in list context.
try { raise InvalidPassword => 'foo'; }
catch {
my ($e) = @_;
my @list = $e->get_composition()
# @list contains ( 'InvalidPassword', 'Base', ... )
};
message
Computes and returns the message associated to the exception. It'll apply the parameters that were set at throw time to the message pattern
of the exception.
STRINGIFICATION
string overloading
All Dancer exceptions properly stringify. When evaluated to a string, they return their message, concatenated with their stack trace (see
below).
cmp overloading
The "cmp" operator is also overloaded, thus all the string operations can be done on Dancer's exceptions, as they will all be based on the
overloaded "cmp" operator. Dancer exceptions wil be compared without their stacktraces.
STACKTRACE
Similarly to Carp, Dancer exceptions stringification appends a string stacktrace to the exception message.
The stacktrace can be a short one, or a long one. Actually the implementation internally uses Carp.
To enable long stack trace (for debugging purpose), you can use the global variable "Dancer::Exception::Verbose" (see below).
The short and long stacktrace snippets are stored within "$self-"{_shortmess}> and "$self-"{_longmess}>. Don't touch them or rely on them,
they are internals, and will change soon.
GLOBAL VARIABLE
$Dancer::Exception::Verbose
When set to 1, exceptions will stringify with a long stack trace. This variable is similar to $Carp::Verbose. I recommend you use it like
that:
local $Dancer::Exception::Verbose;
$Dancer::Exception::Verbose = 1;
All the Carp global variables can also be used to alter the stacktrace generation.
perl v5.14.2 2012-03-31 Dancer::Exception::Base(3pm)