From 6f8ab5670d67c80fe7b06fb50300412318babeec Mon Sep 17 00:00:00 2001
From: Abel Ureta-Vidal <abel@sanger.ac.uk>
Date: Fri, 16 Jul 2004 08:37:36 +0000
Subject: [PATCH] Import all method by default if none is specified. Added
try/catch syntax
---
modules/Bio/EnsEMBL/Utils/Exception.pm | 74 +++++++++++++++++++++++---
1 file changed, 67 insertions(+), 7 deletions(-)
diff --git a/modules/Bio/EnsEMBL/Utils/Exception.pm b/modules/Bio/EnsEMBL/Utils/Exception.pm
index dea57a230d..c3738e69a7 100644
--- a/modules/Bio/EnsEMBL/Utils/Exception.pm
+++ b/modules/Bio/EnsEMBL/Utils/Exception.pm
@@ -8,16 +8,31 @@ Bio::EnsEMBL::Utils::Exception - Utility functions for error handling
=head1 SYNOPSIS
- use Bio::EnsEMBL::Utils::Exception qw(throw warning deprecate verbose)
+ use Bio::EnsEMBL::Utils::Exception qw(throw warning deprecate verbose try catch);
+
+ or to get all methods just
+
+ use Bio::EnsEMBL::Utils::Exception;
eval {
throw("this is an exception with a stack trace");
- );
-
+ };
+
if($@) {
print "Caught exception:\n$@";
}
+ # or you can us the try/catch confortable syntax instead
+ # to deal with throw or die.
+ # don't forget the ";" after the catch block
+ # With this syntax, the original $@ is in $_ in the catch subroutine.
+
+ try {
+ throw("this is an exception with a stack trace");
+ } catch {
+ print "Caught exception:\n$_";
+ };
+
#silence warnings
verbose('OFF');
@@ -74,12 +89,11 @@ package Bio::EnsEMBL::Utils::Exception;
use Exporter;
-use vars qw(@ISA @EXPORT_OK);
+use vars qw(@ISA @EXPORT);
@ISA = qw(Exporter);
-
-@EXPORT_OK = qw(&throw &warning &stack_trace_dump
- &stack_trace &verbose &deprecate &info);
+@EXPORT = qw(throw warning stack_trace_dump
+ stack_trace verbose deprecate info try catch);
my $VERBOSITY = 3000;
my $DEFAULT_INFO = 4000;
@@ -435,6 +449,52 @@ sub deprecate {
$DEPRECATED{"$line:$file"} = 1;
}
+=head2 try/catch
+
+ Arg [1] : anonymous subroutine
+ the block to be tried
+ Arg [2] : return value of the catch function
+ Example : use Bio::EnsEMBL::Utils::Exception qw(throw try catch)
+ The syntax is:
+ try { block1 } catch { block2 };
+ { block1 } is the 1st argument
+ catch { block2 } is the 2nd argument
+ e.g.
+ try {
+ throw("this is an exception with a stack trace");
+ } catch {
+ print "Caught exception:\n$_";
+ };
+ In block2, $_ is assigned the value of the first
+ throw or die statement executed in block 1.
+
+ Description: Replaces the classical syntax
+ eval { block1 };
+ if ($@) { block2 }
+ by a more confortable one.
+ In the try/catch syntax, the original $@ is in $_ in the catch subroutine.
+ This try/catch implementation is a copy and paste from
+ "Programming Perl" 3rd Edition, July 2000, by L.Wall, T. Christiansen
+ & J. Orwant. p227, and is only possible because of the possibility of
+ subroutine prototypes.
+ Returntype : implemented by the catch block
+ Exceptions : none
+ Caller : general
+
+=cut
+sub try (&$) {
+ my ($try, $catch) = @_;
+ eval { &$try };
+ if ($@) {
+ chop $@;
+ local $_ = $@;
+ &$catch;
+ }
+}
+
+sub catch (&) {
+ shift;
+}
1;
--
GitLab