Current File : //usr/share/perl5/vendor_perl/CPAN/Meta/YAML.pm
use 5.008001; # sane UTF-8 support
use strict;
use warnings;
package CPAN::Meta::YAML; # git description: v1.68-2-gcc5324e
# XXX-INGY is 5.8.1 too old/broken for utf8?
# XXX-XDG Lancaster consensus was that it was sufficient until
# proven otherwise
$CPAN::Meta::YAML::VERSION = '0.018';
; # original $VERSION removed by Doppelgaenger
#####################################################################
# The CPAN::Meta::YAML API.
#
# These are the currently documented API functions/methods and
# exports:
use Exporter;
our @ISA = qw{ Exporter };
our @EXPORT = qw{ Load Dump };
our @EXPORT_OK = qw{ LoadFile DumpFile freeze thaw };
###
# Functional/Export API:
sub Dump {
return CPAN::Meta::YAML->new(@_)->_dump_string;
}
# XXX-INGY Returning last document seems a bad behavior.
# XXX-XDG I think first would seem more natural, but I don't know
# that it's worth changing now
sub Load {
my $self = CPAN::Meta::YAML->_load_string(@_);
if ( wantarray ) {
return @$self;
} else {
# To match YAML.pm, return the last document
return $self->[-1];
}
}
# XXX-INGY Do we really need freeze and thaw?
# XXX-XDG I don't think so. I'd support deprecating them.
BEGIN {
*freeze = \&Dump;
*thaw = \&Load;
}
sub DumpFile {
my $file = shift;
return CPAN::Meta::YAML->new(@_)->_dump_file($file);
}
sub LoadFile {
my $file = shift;
my $self = CPAN::Meta::YAML->_load_file($file);
if ( wantarray ) {
return @$self;
} else {
# Return only the last document to match YAML.pm,
return $self->[-1];
}
}
###
# Object Oriented API:
# Create an empty CPAN::Meta::YAML object
# XXX-INGY Why do we use ARRAY object?
# NOTE: I get it now, but I think it's confusing and not needed.
# Will change it on a branch later, for review.
#
# XXX-XDG I don't support changing it yet. It's a very well-documented
# "API" of CPAN::Meta::YAML. I'd support deprecating it, but Adam suggested
# we not change it until YAML.pm's own OO API is established so that
# users only have one API change to digest, not two
sub new {
my $class = shift;
bless [ @_ ], $class;
}
# XXX-INGY It probably doesn't matter, and it's probably too late to
# change, but 'read/write' are the wrong names. Read and Write
# are actions that take data from storage to memory
# characters/strings. These take the data to/from storage to native
# Perl objects, which the terms dump and load are meant. As long as
# this is a legacy quirk to CPAN::Meta::YAML it's ok, but I'd prefer not
# to add new {read,write}_* methods to this API.
sub read_string {
my $self = shift;
$self->_load_string(@_);
}
sub write_string {
my $self = shift;
$self->_dump_string(@_);
}
sub read {
my $self = shift;
$self->_load_file(@_);
}
sub write {
my $self = shift;
$self->_dump_file(@_);
}
#####################################################################
# Constants
# Printed form of the unprintable characters in the lowest range
# of ASCII characters, listed by ASCII ordinal position.
my @UNPRINTABLE = qw(
0 x01 x02 x03 x04 x05 x06 a
b t n v f r x0E x0F
x10 x11 x12 x13 x14 x15 x16 x17
x18 x19 x1A e x1C x1D x1E x1F
);
# Printable characters for escapes
my %UNESCAPES = (
0 => "\x00", z => "\x00", N => "\x85",
a => "\x07", b => "\x08", t => "\x09",
n => "\x0a", v => "\x0b", f => "\x0c",
r => "\x0d", e => "\x1b", '\\' => '\\',
);
# XXX-INGY
# I(ngy) need to decide if these values should be quoted in
# CPAN::Meta::YAML or not. Probably yes.
# These 3 values have special meaning when unquoted and using the
# default YAML schema. They need quotes if they are strings.
my %QUOTE = map { $_ => 1 } qw{
null true false
};
# The commented out form is simpler, but overloaded the Perl regex
# engine due to recursion and backtracking problems on strings
# larger than 32,000ish characters. Keep it for reference purposes.
# qr/\"((?:\\.|[^\"])*)\"/
my $re_capture_double_quoted = qr/\"([^\\"]*(?:\\.[^\\"]*)*)\"/;
my $re_capture_single_quoted = qr/\'([^\']*(?:\'\'[^\']*)*)\'/;
# unquoted re gets trailing space that needs to be stripped
my $re_capture_unquoted_key = qr/([^:]+(?::+\S(?:[^:]*|.*?(?=:)))*)(?=\s*\:(?:\s+|$))/;
my $re_trailing_comment = qr/(?:\s+\#.*)?/;
my $re_key_value_separator = qr/\s*:(?:\s+(?:\#.*)?|$)/;
#####################################################################
# CPAN::Meta::YAML Implementation.
#
# These are the private methods that do all the work. They may change
# at any time.
###
# Loader functions:
# Create an object from a file
sub _load_file {
my $class = ref $_[0] ? ref shift : shift;
# Check the file
my $file = shift or $class->_error( 'You did not specify a file name' );
$class->_error( "File '$file' does not exist" )
unless -e $file;
$class->_error( "'$file' is a directory, not a file" )
unless -f _;
$class->_error( "Insufficient permissions to read '$file'" )
unless -r _;
# Open unbuffered with strict UTF-8 decoding and no translation layers
open( my $fh, "<:unix:encoding(UTF-8)", $file );
unless ( $fh ) {
$class->_error("Failed to open file '$file': $!");
}
# flock if available (or warn if not possible for OS-specific reasons)
if ( _can_flock() ) {
flock( $fh, Fcntl::LOCK_SH() )
or warn "Couldn't lock '$file' for reading: $!";
}
# slurp the contents
my $contents = eval {
use warnings FATAL => 'utf8';
local $/;
<$fh>
};
if ( my $err = $@ ) {
$class->_error("Error reading from file '$file': $err");
}
# close the file (release the lock)
unless ( close $fh ) {
$class->_error("Failed to close file '$file': $!");
}
$class->_load_string( $contents );
}
# Create an object from a string
sub _load_string {
my $class = ref $_[0] ? ref shift : shift;
my $self = bless [], $class;
my $string = $_[0];
eval {
unless ( defined $string ) {
die \"Did not provide a string to load";
}
# Check if Perl has it marked as characters, but it's internally
# inconsistent. E.g. maybe latin1 got read on a :utf8 layer
if ( utf8::is_utf8($string) && ! utf8::valid($string) ) {
die \<<'...';
Read an invalid UTF-8 string (maybe mixed UTF-8 and 8-bit character set).
Did you decode with lax ":utf8" instead of strict ":encoding(UTF-8)"?
...
}
# Ensure Unicode character semantics, even for 0x80-0xff
utf8::upgrade($string);
# Check for and strip any leading UTF-8 BOM
$string =~ s/^\x{FEFF}//;
# Check for some special cases
return $self unless length $string;
# Split the file into lines
my @lines = grep { ! /^\s*(?:\#.*)?\z/ }
split /(?:\015{1,2}\012|\015|\012)/, $string;
# Strip the initial YAML header
@lines and $lines[0] =~ /^\%YAML[: ][\d\.]+.*\z/ and shift @lines;
# A nibbling parser
my $in_document = 0;
while ( @lines ) {
# Do we have a document header?
if ( $lines[0] =~ /^---\s*(?:(.+)\s*)?\z/ ) {
# Handle scalar documents
shift @lines;
if ( defined $1 and $1 !~ /^(?:\#.+|\%YAML[: ][\d\.]+)\z/ ) {
push @$self,
$self->_load_scalar( "$1", [ undef ], \@lines );
next;
}
$in_document = 1;
}
if ( ! @lines or $lines[0] =~ /^(?:---|\.\.\.)/ ) {
# A naked document
push @$self, undef;
while ( @lines and $lines[0] !~ /^---/ ) {
shift @lines;
}
$in_document = 0;
# XXX The final '-+$' is to look for -- which ends up being an
# error later.
} elsif ( ! $in_document && @$self ) {
# only the first document can be explicit
die \"CPAN::Meta::YAML failed to classify the line '$lines[0]'";
} elsif ( $lines[0] =~ /^\s*\-(?:\s|$|-+$)/ ) {
# An array at the root
my $document = [ ];
push @$self, $document;
$self->_load_array( $document, [ 0 ], \@lines );
} elsif ( $lines[0] =~ /^(\s*)\S/ ) {
# A hash at the root
my $document = { };
push @$self, $document;
$self->_load_hash( $document, [ length($1) ], \@lines );
} else {
# Shouldn't get here. @lines have whitespace-only lines
# stripped, and previous match is a line with any
# non-whitespace. So this clause should only be reachable via
# a perlbug where \s is not symmetric with \S
# uncoverable statement
die \"CPAN::Meta::YAML failed to classify the line '$lines[0]'";
}
}
};
my $err = $@;
if ( ref $err eq 'SCALAR' ) {
$self->_error(${$err});
} elsif ( $err ) {
$self->_error($err);
}
return $self;
}
sub _unquote_single {
my ($self, $string) = @_;
return '' unless length $string;
$string =~ s/\'\'/\'/g;
return $string;
}
sub _unquote_double {
my ($self, $string) = @_;
return '' unless length $string;
$string =~ s/\\"/"/g;
$string =~
s{\\([Nnever\\fartz0b]|x([0-9a-fA-F]{2}))}
{(length($1)>1)?pack("H2",$2):$UNESCAPES{$1}}gex;
return $string;
}
# Load a YAML scalar string to the actual Perl scalar
sub _load_scalar {
my ($self, $string, $indent, $lines) = @_;
# Trim trailing whitespace
$string =~ s/\s*\z//;
# Explitic null/undef
return undef if $string eq '~';
# Single quote
if ( $string =~ /^$re_capture_single_quoted$re_trailing_comment\z/ ) {
return $self->_unquote_single($1);
}
# Double quote.
if ( $string =~ /^$re_capture_double_quoted$re_trailing_comment\z/ ) {
return $self->_unquote_double($1);
}
# Special cases
if ( $string =~ /^[\'\"!&]/ ) {
die \"CPAN::Meta::YAML does not support a feature in line '$string'";
}
return {} if $string =~ /^{}(?:\s+\#.*)?\z/;
return [] if $string =~ /^\[\](?:\s+\#.*)?\z/;
# Regular unquoted string
if ( $string !~ /^[>|]/ ) {
die \"CPAN::Meta::YAML found illegal characters in plain scalar: '$string'"
if $string =~ /^(?:-(?:\s|$)|[\@\%\`])/ or
$string =~ /:(?:\s|$)/;
$string =~ s/\s+#.*\z//;
return $string;
}
# Error
die \"CPAN::Meta::YAML failed to find multi-line scalar content" unless @$lines;
# Check the indent depth
$lines->[0] =~ /^(\s*)/;
$indent->[-1] = length("$1");
if ( defined $indent->[-2] and $indent->[-1] <= $indent->[-2] ) {
die \"CPAN::Meta::YAML found bad indenting in line '$lines->[0]'";
}
# Pull the lines
my @multiline = ();
while ( @$lines ) {
$lines->[0] =~ /^(\s*)/;
last unless length($1) >= $indent->[-1];
push @multiline, substr(shift(@$lines), length($1));
}
my $j = (substr($string, 0, 1) eq '>') ? ' ' : "\n";
my $t = (substr($string, 1, 1) eq '-') ? '' : "\n";
return join( $j, @multiline ) . $t;
}
# Load an array
sub _load_array {
my ($self, $array, $indent, $lines) = @_;
while ( @$lines ) {
# Check for a new document
if ( $lines->[0] =~ /^(?:---|\.\.\.)/ ) {
while ( @$lines and $lines->[0] !~ /^---/ ) {
shift @$lines;
}
return 1;
}
# Check the indent level
$lines->[0] =~ /^(\s*)/;
if ( length($1) < $indent->[-1] ) {
return 1;
} elsif ( length($1) > $indent->[-1] ) {
die \"CPAN::Meta::YAML found bad indenting in line '$lines->[0]'";
}
if ( $lines->[0] =~ /^(\s*\-\s+)[^\'\"]\S*\s*:(?:\s+|$)/ ) {
# Inline nested hash
my $indent2 = length("$1");
$lines->[0] =~ s/-/ /;
push @$array, { };
$self->_load_hash( $array->[-1], [ @$indent, $indent2 ], $lines );
} elsif ( $lines->[0] =~ /^\s*\-\s*\z/ ) {
shift @$lines;
unless ( @$lines ) {
push @$array, undef;
return 1;
}
if ( $lines->[0] =~ /^(\s*)\-/ ) {
my $indent2 = length("$1");
if ( $indent->[-1] == $indent2 ) {
# Null array entry
push @$array, undef;
} else {
# Naked indenter
push @$array, [ ];
$self->_load_array(
$array->[-1], [ @$indent, $indent2 ], $lines
);
}
} elsif ( $lines->[0] =~ /^(\s*)\S/ ) {
push @$array, { };
$self->_load_hash(
$array->[-1], [ @$indent, length("$1") ], $lines
);
} else {
die \"CPAN::Meta::YAML failed to classify line '$lines->[0]'";
}
} elsif ( $lines->[0] =~ /^\s*\-(\s*)(.+?)\s*\z/ ) {
# Array entry with a value
shift @$lines;
push @$array, $self->_load_scalar(
"$2", [ @$indent, undef ], $lines
);
} elsif ( defined $indent->[-2] and $indent->[-1] == $indent->[-2] ) {
# This is probably a structure like the following...
# ---
# foo:
# - list
# bar: value
#
# ... so lets return and let the hash parser handle it
return 1;
} else {
die \"CPAN::Meta::YAML failed to classify line '$lines->[0]'";
}
}
return 1;
}
# Load a hash
sub _load_hash {
my ($self, $hash, $indent, $lines) = @_;
while ( @$lines ) {
# Check for a new document
if ( $lines->[0] =~ /^(?:---|\.\.\.)/ ) {
while ( @$lines and $lines->[0] !~ /^---/ ) {
shift @$lines;
}
return 1;
}
# Check the indent level
$lines->[0] =~ /^(\s*)/;
if ( length($1) < $indent->[-1] ) {
return 1;
} elsif ( length($1) > $indent->[-1] ) {
die \"CPAN::Meta::YAML found bad indenting in line '$lines->[0]'";
}
# Find the key
my $key;
# Quoted keys
if ( $lines->[0] =~
s/^\s*$re_capture_single_quoted$re_key_value_separator//
) {
$key = $self->_unquote_single($1);
}
elsif ( $lines->[0] =~
s/^\s*$re_capture_double_quoted$re_key_value_separator//
) {
$key = $self->_unquote_double($1);
}
elsif ( $lines->[0] =~
s/^\s*$re_capture_unquoted_key$re_key_value_separator//
) {
$key = $1;
$key =~ s/\s+$//;
}
elsif ( $lines->[0] =~ /^\s*\?/ ) {
die \"CPAN::Meta::YAML does not support a feature in line '$lines->[0]'";
}
else {
die \"CPAN::Meta::YAML failed to classify line '$lines->[0]'";
}
if ( exists $hash->{$key} ) {
warn "CPAN::Meta::YAML found a duplicate key '$key' in line '$lines->[0]'";
}
# Do we have a value?
if ( length $lines->[0] ) {
# Yes
$hash->{$key} = $self->_load_scalar(
shift(@$lines), [ @$indent, undef ], $lines
);
} else {
# An indent
shift @$lines;
unless ( @$lines ) {
$hash->{$key} = undef;
return 1;
}
if ( $lines->[0] =~ /^(\s*)-/ ) {
$hash->{$key} = [];
$self->_load_array(
$hash->{$key}, [ @$indent, length($1) ], $lines
);
} elsif ( $lines->[0] =~ /^(\s*)./ ) {
my $indent2 = length("$1");
if ( $indent->[-1] >= $indent2 ) {
# Null hash entry
$hash->{$key} = undef;
} else {
$hash->{$key} = {};
$self->_load_hash(
$hash->{$key}, [ @$indent, length($1) ], $lines
);
}
}
}
}
return 1;
}
###
# Dumper functions:
# Save an object to a file
sub _dump_file {
my $self = shift;
require Fcntl;
# Check the file
my $file = shift or $self->_error( 'You did not specify a file name' );
my $fh;
# flock if available (or warn if not possible for OS-specific reasons)
if ( _can_flock() ) {
# Open without truncation (truncate comes after lock)
my $flags = Fcntl::O_WRONLY()|Fcntl::O_CREAT();
sysopen( $fh, $file, $flags );
unless ( $fh ) {
$self->_error("Failed to open file '$file' for writing: $!");
}
# Use no translation and strict UTF-8
binmode( $fh, ":raw:encoding(UTF-8)");
flock( $fh, Fcntl::LOCK_EX() )
or warn "Couldn't lock '$file' for reading: $!";
# truncate and spew contents
truncate $fh, 0;
seek $fh, 0, 0;
}
else {
open $fh, ">:unix:encoding(UTF-8)", $file;
}
# serialize and spew to the handle
print {$fh} $self->_dump_string;
# close the file (release the lock)
unless ( close $fh ) {
$self->_error("Failed to close file '$file': $!");
}
return 1;
}
# Save an object to a string
sub _dump_string {
my $self = shift;
return '' unless ref $self && @$self;
# Iterate over the documents
my $indent = 0;
my @lines = ();
eval {
foreach my $cursor ( @$self ) {
push @lines, '---';
# An empty document
if ( ! defined $cursor ) {
# Do nothing
# A scalar document
} elsif ( ! ref $cursor ) {
$lines[-1] .= ' ' . $self->_dump_scalar( $cursor );
# A list at the root
} elsif ( ref $cursor eq 'ARRAY' ) {
unless ( @$cursor ) {
$lines[-1] .= ' []';
next;
}
push @lines, $self->_dump_array( $cursor, $indent, {} );
# A hash at the root
} elsif ( ref $cursor eq 'HASH' ) {
unless ( %$cursor ) {
$lines[-1] .= ' {}';
next;
}
push @lines, $self->_dump_hash( $cursor, $indent, {} );
} else {
die \("Cannot serialize " . ref($cursor));
}
}
};
if ( ref $@ eq 'SCALAR' ) {
$self->_error(${$@});
} elsif ( $@ ) {
$self->_error($@);
}
join '', map { "$_\n" } @lines;
}
sub _has_internal_string_value {
my $value = shift;
my $b_obj = B::svref_2object(\$value); # for round trip problem
return $b_obj->FLAGS & B::SVf_POK();
}
sub _dump_scalar {
my $string = $_[1];
my $is_key = $_[2];
# Check this before checking length or it winds up looking like a string!
my $has_string_flag = _has_internal_string_value($string);
return '~' unless defined $string;
return "''" unless length $string;
if (Scalar::Util::looks_like_number($string)) {
# keys and values that have been used as strings get quoted
if ( $is_key || $has_string_flag ) {
return qq['$string'];
}
else {
return $string;
}
}
if ( $string =~ /[\x00-\x09\x0b-\x0d\x0e-\x1f\x7f-\x9f\'\n]/ ) {
$string =~ s/\\/\\\\/g;
$string =~ s/"/\\"/g;
$string =~ s/\n/\\n/g;
$string =~ s/[\x85]/\\N/g;
$string =~ s/([\x00-\x1f])/\\$UNPRINTABLE[ord($1)]/g;
$string =~ s/([\x7f-\x9f])/'\x' . sprintf("%X",ord($1))/ge;
return qq|"$string"|;
}
if ( $string =~ /(?:^[~!@#%&*|>?:,'"`{}\[\]]|^-+$|\s|:\z)/ or
$QUOTE{$string}
) {
return "'$string'";
}
return $string;
}
sub _dump_array {
my ($self, $array, $indent, $seen) = @_;
if ( $seen->{refaddr($array)}++ ) {
die \"CPAN::Meta::YAML does not support circular references";
}
my @lines = ();
foreach my $el ( @$array ) {
my $line = (' ' x $indent) . '-';
my $type = ref $el;
if ( ! $type ) {
$line .= ' ' . $self->_dump_scalar( $el );
push @lines, $line;
} elsif ( $type eq 'ARRAY' ) {
if ( @$el ) {
push @lines, $line;
push @lines, $self->_dump_array( $el, $indent + 1, $seen );
} else {
$line .= ' []';
push @lines, $line;
}
} elsif ( $type eq 'HASH' ) {
if ( keys %$el ) {
push @lines, $line;
push @lines, $self->_dump_hash( $el, $indent + 1, $seen );
} else {
$line .= ' {}';
push @lines, $line;
}
} else {
die \"CPAN::Meta::YAML does not support $type references";
}
}
@lines;
}
sub _dump_hash {
my ($self, $hash, $indent, $seen) = @_;
if ( $seen->{refaddr($hash)}++ ) {
die \"CPAN::Meta::YAML does not support circular references";
}
my @lines = ();
foreach my $name ( sort keys %$hash ) {
my $el = $hash->{$name};
my $line = (' ' x $indent) . $self->_dump_scalar($name, 1) . ":";
my $type = ref $el;
if ( ! $type ) {
$line .= ' ' . $self->_dump_scalar( $el );
push @lines, $line;
} elsif ( $type eq 'ARRAY' ) {
if ( @$el ) {
push @lines, $line;
push @lines, $self->_dump_array( $el, $indent + 1, $seen );
} else {
$line .= ' []';
push @lines, $line;
}
} elsif ( $type eq 'HASH' ) {
if ( keys %$el ) {
push @lines, $line;
push @lines, $self->_dump_hash( $el, $indent + 1, $seen );
} else {
$line .= ' {}';
push @lines, $line;
}
} else {
die \"CPAN::Meta::YAML does not support $type references";
}
}
@lines;
}
#####################################################################
# DEPRECATED API methods:
# Error storage (DEPRECATED as of 1.57)
our $errstr = '';
# Set error
sub _error {
require Carp;
$errstr = $_[1];
$errstr =~ s/ at \S+ line \d+.*//;
Carp::croak( $errstr );
}
# Retrieve error
my $errstr_warned;
sub errstr {
require Carp;
Carp::carp( "CPAN::Meta::YAML->errstr and \$CPAN::Meta::YAML::errstr is deprecated" )
unless $errstr_warned++;
$errstr;
}
#####################################################################
# Helper functions. Possibly not needed.
# Use to detect nv or iv
use B;
# XXX-INGY Is flock CPAN::Meta::YAML's responsibility?
# Some platforms can't flock :-(
# XXX-XDG I think it is. When reading and writing files, we ought
# to be locking whenever possible. People (foolishly) use YAML
# files for things like session storage, which has race issues.
my $HAS_FLOCK;
sub _can_flock {
if ( defined $HAS_FLOCK ) {
return $HAS_FLOCK;
}
else {
require Config;
my $c = \%Config::Config;
$HAS_FLOCK = grep { $c->{$_} } qw/d_flock d_fcntl_can_lock d_lockf/;
require Fcntl if $HAS_FLOCK;
return $HAS_FLOCK;
}
}
# XXX-INGY Is this core in 5.8.1? Can we remove this?
# XXX-XDG Scalar::Util 1.18 didn't land until 5.8.8, so we need this
#####################################################################
# Use Scalar::Util if possible, otherwise emulate it
use Scalar::Util ();
BEGIN {
local $@;
if ( eval { Scalar::Util->VERSION(1.18); } ) {
*refaddr = *Scalar::Util::refaddr;
}
else {
eval <<'END_PERL';
# Scalar::Util failed to load or too old
sub refaddr {
my $pkg = ref($_[0]) or return undef;
if ( !! UNIVERSAL::can($_[0], 'can') ) {
bless $_[0], 'Scalar::Util::Fake';
} else {
$pkg = undef;
}
"$_[0]" =~ /0x(\w+)/;
my $i = do { no warnings 'portable'; hex $1 };
bless $_[0], $pkg if defined $pkg;
$i;
}
END_PERL
}
}
delete $CPAN::Meta::YAML::{refaddr};
1;
# XXX-INGY Doc notes I'm putting up here. Changing the doc when it's wrong
# but leaving grey area stuff up here.
#
# I would like to change Read/Write to Load/Dump below without
# changing the actual API names.
#
# It might be better to put Load/Dump API in the SYNOPSIS instead of the
# dubious OO API.
#
# null and bool explanations may be outdated.
=pod
=encoding UTF-8
=head1 NAME
CPAN::Meta::YAML - Read and write a subset of YAML for CPAN Meta files
=head1 VERSION
version 0.018
=head1 SYNOPSIS
use CPAN::Meta::YAML;
# reading a META file
open $fh, "<:utf8", "META.yml";
$yaml_text = do { local $/; <$fh> };
$yaml = CPAN::Meta::YAML->read_string($yaml_text)
or die CPAN::Meta::YAML->errstr;
# finding the metadata
$meta = $yaml->[0];
# writing a META file
$yaml_text = $yaml->write_string
or die CPAN::Meta::YAML->errstr;
open $fh, ">:utf8", "META.yml";
print $fh $yaml_text;
=head1 DESCRIPTION
This module implements a subset of the YAML specification for use in reading
and writing CPAN metadata files like F<META.yml> and F<MYMETA.yml>. It should
not be used for any other general YAML parsing or generation task.
NOTE: F<META.yml> (and F<MYMETA.yml>) files should be UTF-8 encoded. Users are
responsible for proper encoding and decoding. In particular, the C<read> and
C<write> methods do B<not> support UTF-8 and should not be used.
=head1 SUPPORT
This module is currently derived from L<YAML::Tiny> by Adam Kennedy. If
there are bugs in how it parses a particular META.yml file, please file
a bug report in the YAML::Tiny bugtracker:
L<https://github.com/Perl-Toolchain-Gang/YAML-Tiny/issues>
=head1 SEE ALSO
L<YAML::Tiny>, L<YAML>, L<YAML::XS>
=head1 AUTHORS
=over 4
=item *
Adam Kennedy <adamk@cpan.org>
=item *
David Golden <dagolden@cpan.org>
=back
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2010 by Adam Kennedy.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut
__END__
# ABSTRACT: Read and write a subset of YAML for CPAN Meta files
Mini Shell