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inc/inc_Module-Build/Module/Build/YAML.pm  view on Meta::CPAN

# Adapted from YAML::Tiny 1.40
package Module::Build::YAML;

use strict;
use Carp 'croak';

# UTF Support?
sub HAVE_UTF8 () { $] >= 5.007003 }
BEGIN {
	if ( HAVE_UTF8 ) {
		# The string eval helps hide this from Test::MinimumVersion
		eval "require utf8;";
		die "Failed to load UTF-8 support" if $@;
	}

	# Class structure
	require 5.004;

	$Module::Build::YAML::VERSION   = '1.40';

	# Error storage
	$Module::Build::YAML::errstr    = '';
}

# The character class of all characters we need to escape
# NOTE: Inlined, since it's only used once
# my $RE_ESCAPE   = '[\\x00-\\x08\\x0b-\\x0d\\x0e-\\x1f\"\n]';

# Printed form of the unprintable characters in the lowest range
# of ASCII characters, listed by ASCII ordinal position.
my @UNPRINTABLE = qw(
	z    x01  x02  x03  x04  x05  x06  a
	x08  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 = (
	z => "\x00", a => "\x07", t    => "\x09",
	n => "\x0a", v => "\x0b", f    => "\x0c",
	r => "\x0d", e => "\x1b", '\\' => '\\',
);

# Special magic boolean words
my %QUOTE = map { $_ => 1 } qw{
	null Null NULL
	y Y yes Yes YES n N no No NO
	true True TRUE false False FALSE
	on On ON off Off OFF
};

#####################################################################
# Implementation

# Create an empty Module::Build::YAML object
sub new {
	my $class = shift;
	bless [ @_ ], $class;
}

# Create an object from a file
sub read {
	my $class = ref $_[0] ? ref shift : shift;

	# Check the file
	my $file = shift or return $class->_error( 'You did not specify a file name' );
	return $class->_error( "File '$file' does not exist" )              unless -e $file;
	return $class->_error( "'$file' is a directory, not a file" )       unless -f _;
	return $class->_error( "Insufficient permissions to read '$file'" ) unless -r _;

	# Slurp in the file
	local $/ = undef;
	local *CFG;
	unless ( open(CFG, $file) ) {
		return $class->_error("Failed to open file '$file': $!");
	}
	my $contents = <CFG>;
	unless ( close(CFG) ) {
		return $class->_error("Failed to close file '$file': $!");
	}

	$class->read_string( $contents );
}

# Create an object from a string
sub read_string {
	my $class  = ref $_[0] ? ref shift : shift;
	my $self   = bless [], $class;
	my $string = $_[0];
	unless ( defined $string ) {
		return $self->_error("Did not provide a string to load");
	}

	# Byte order marks
	# NOTE: Keeping this here to educate maintainers
	# my %BOM = (
	#     "\357\273\277" => 'UTF-8',
	#     "\376\377"     => 'UTF-16BE',
	#     "\377\376"     => 'UTF-16LE',
	#     "\377\376\0\0" => 'UTF-32LE'
	#     "\0\0\376\377" => 'UTF-32BE',
	# );
	if ( $string =~ /^(?:\376\377|\377\376|\377\376\0\0|\0\0\376\377)/ ) {
		return $self->_error("Stream has a non UTF-8 BOM");
	} else {
		# Strip UTF-8 bom if found, we'll just ignore it
		$string =~ s/^\357\273\277//;
	}

	# Try to decode as utf8
	utf8::decode($string) if HAVE_UTF8;

	# Check for some special cases
	return $self unless length $string;
	unless ( $string =~ /[\012\015]+\z/ ) {
		return $self->_error("Stream does not end with newline character");
	}

	# 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
	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->_read_scalar( "$1", [ undef ], \@lines );
				next;
			}
		}

		if ( ! @lines or $lines[0] =~ /^(?:---|\.\.\.)/ ) {
			# A naked document
			push @$self, undef;
			while ( @lines and $lines[0] !~ /^---/ ) {
				shift @lines;
			}

		} elsif ( $lines[0] =~ /^\s*\-/ ) {
			# An array at the root
			my $document = [ ];
			push @$self, $document;
			$self->_read_array( $document, [ 0 ], \@lines );

		} elsif ( $lines[0] =~ /^(\s*)\S/ ) {
			# A hash at the root
			my $document = { };
			push @$self, $document;
			$self->_read_hash( $document, [ length($1) ], \@lines );

		} else {
			croak("Module::Build::YAML failed to classify the line '$lines[0]'");
		}
	}

	$self;
}

# Deparse a scalar string to the actual scalar
sub _read_scalar {
	my ($self, $string, $indent, $lines) = @_;

	# Trim trailing whitespace
	$string =~ s/\s*\z//;