ch13.065_best

来自「Perl Best Practices the source code」· 065_BEST 代码 · 共 46 行

##############################################################################
##   Code fragment (Recommended) from Chapter 13 of "Perl Best Practices"   ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;




sub try_next_line {
    # Give get_next_line() two chances...
    for my $already_retried (0..1) {
 
        # Return immediately on success, but catch any failure...
        eval { 
            return get_next_line()
        };
 
        # If we can handle this exception...
        if (X::EOF->caught() ) {
            my $exception = $EVAL_ERROR;
        
            # Fail on irremedially bad cases...
            fail_if_incorrigible($exception, $already_retried);
                    
            # Otherwise, try rewinding the filehandle...
            seek $exception->fh(), 0, 0;
        }
        # Otherwise, let some caller handle it...
        else {
            $EVAL_ERROR->rethrow();
        }
    }
}