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inc/YAML/Tiny.pm  view on Meta::CPAN

    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 \"YAML::Tiny 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 \"YAML::Tiny failed to classify the line '$lines[0]'";