What are common pitfalls or gotchas with YAML handling (YAML::XS)?

When working with YAML in Perl using the YAML::XS module, developers should be aware of several common pitfalls and “gotchas” that can lead to unexpected behavior or errors. This guide outlines these issues and provides examples to help you avoid them.

# Example of common pitfalls with YAML::XS
use YAML::XS 'LoadFile';

my $data;
eval {
    $data = LoadFile('config.yaml'); # Loading YAML file
};

if ($@) {
    warn "Failed to load YAML: $@"; # Handle parsing errors
}

# Be cautious of scalar types and implicit typing
my $yaml_string = "string: 'This is a string'\nnumber: 123";
my $loaded_data = Load($yaml_string);
print $loaded_data->{string}; # Outputs: This is a string
print $loaded_data->{number}; # Outputs: 123

# Ensure you handle complex structures properly
my $complex_yaml = <<'END';
fruits:
  - apple
  - banana
vegetables:
  - carrot
  - celery
END

my $data_structure = Load($complex_yaml);
print join(", ", @{$data_structure->{fruits}}); # Outputs: apple, banana