package CPAN::Meta::YAML; BEGIN { $CPAN::Meta::YAML::VERSION = '0.003'; } use strict; # 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; require Exporter; require Carp; @CPAN::Meta::YAML::ISA = qw{ Exporter }; @CPAN::Meta::YAML::EXPORT = qw{ Load Dump }; @CPAN::Meta::YAML::EXPORT_OK = qw{ LoadFile DumpFile freeze thaw }; # Error storage $CPAN::Meta::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 CPAN::Meta::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 = ; 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]; eval { unless ( defined $string ) { die \"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)/ ) { die \"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/ ) { die \"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($1) ], \@lines ); } else { die \"CPAN::Meta::YAML failed to classify the line '$lines[0]'"; } } }; if ( ref $@ eq 'SCALAR' ) { return $self->_error(${$@}); } elsif ( $@ ) { require Carp; Carp::croak($@); } return $self; } # Deparse a scalar string to the actual scalar sub _read_scalar { my ($self, $string, $indent, $lines) = @_; # Trim trailing whitespace $string =~ s/\s*\z//; # Explitic null/undef return undef if $string eq '~'; # Single quote if ( $string =~ /^\'(.*?)\'(?:\s+\#.*)?\z/ ) { return '' unless defined $1; $string = $1; $string =~ s/\'\'/\'/g; return $string; } # Double quote. # 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. # if ( $string =~ /^\"((?:\\.|[^\"])*)\"\z/ ) { if ( $string =~ /^\"([^\\"]*(?:\\.[^\\"]*)*)\"(?:\s+\#.*)?\z/ ) { # Reusing the variable is a little ugly, # but avoids a new variable and a string copy. $string = $1; $string =~ s/\\"/"/g; $string =~ s/\\([never\\fartz]|x([0-9a-fA-F]{2}))/(length($1)>1)?pack("H2",$2):$UNESCAPES{$1}/gex; return $string; } # 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 !~ /^[>|]/ ) { if ( $string =~ /^(?:-(?:\s|$)|[\@\%\`])/ or $string =~ /:(?:\s|$)/ ) { die \"CPAN::Meta::YAML found illegal characters in plain scalar: '$string'"; } $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 ) . $t; } # Parse an array sub _read_array { my ($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->_read_hash( $array->[-1], [ @$indent, $indent2 ], $lines ); } elsif ( $lines->[0] =~ /^\s*\-(\s*)(.+?)\s*\z/ ) { # Array entry with a value shift @$lines; push @$array, $self->_read_scalar( "$2", [ @$indent, undef ], $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->_read_array( $array->[-1], [ @$indent, $indent2 ], $lines ); } } elsif ( $lines->[0] =~ /^(\s*)\S/ ) { push @$array, { }; $self->_read_hash( $array->[-1], [ @$indent, length("$1") ], $lines ); } else { die \"CPAN::Meta::YAML failed to classify line '$lines->[0]'"; } } 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; } # Parse an array sub _read_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]'"; } # Get the key unless ( $lines->[0] =~ s/^\s*([^\'\" ][^\n]*?)\s*:(\s+(?:\#.*)?|$)// ) { if ( $lines->[0] =~ /^\s*[?\'\"]/ ) { die \"CPAN::Meta::YAML does not support a feature in line '$lines->[0]'"; } die \"CPAN::Meta::YAML failed to classify line '$lines->[0]'"; } my $key = $1; # Do we have a value? if ( length $lines->[0] ) { # Yes $hash->{$key} = $self->_read_scalar( shift(@$lines), [ @$indent, undef ], $lines ); } else { # An indent shift @$lines; unless ( @$lines ) { $hash->{$key} = undef; return 1; } if ( $lines->[0] =~ /^(\s*)-/ ) { $hash->{$key} = []; $self->_read_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->_read_hash( $hash->{$key}, [ @$indent, length($1) ], $lines ); } } } } return 1; } # Save an object to a file sub write { my $self = shift; my $file = shift or return $self->_error('No file name provided'); # Write it to the file open( CFG, '>' . $file ) or return $self->_error( "Failed to open file '$file' for writing: $!" ); print CFG $self->write_string; close CFG; return 1; } # Save an object to a string sub write_string { my $self = shift; return '' unless @$self; # Iterate over the documents my $indent = 0; my @lines = (); foreach my $cursor ( @$self ) { push @lines, '---'; # An empty document if ( ! defined $cursor ) { # Do nothing # A scalar document } elsif ( ! ref $cursor ) { $lines[-1] .= ' ' . $self->_write_scalar( $cursor, $indent ); # A list at the root } elsif ( ref $cursor eq 'ARRAY' ) { unless ( @$cursor ) { $lines[-1] .= ' []'; next; } push @lines, $self->_write_array( $cursor, $indent, {} ); # A hash at the root } elsif ( ref $cursor eq 'HASH' ) { unless ( %$cursor ) { $lines[-1] .= ' {}'; next; } push @lines, $self->_write_hash( $cursor, $indent, {} ); } else { Carp::croak("Cannot serialize " . ref($cursor)); } } join '', map { "$_\n" } @lines; } sub _write_scalar { my $string = $_[1]; return '~' unless defined $string; return "''" unless length $string; if ( $string =~ /[\x00-\x08\x0b-\x0d\x0e-\x1f\"\'\n]/ ) { $string =~ s/\\/\\\\/g; $string =~ s/"/\\"/g; $string =~ s/\n/\\n/g; $string =~ s/([\x00-\x1f])/\\$UNPRINTABLE[ord($1)]/g; return qq|"$string"|; } if ( $string =~ /(?:^\W|\s)/ or $QUOTE{$string} ) { return "'$string'"; } return $string; } sub _write_array { my ($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->_write_scalar( $el, $indent + 1 ); push @lines, $line; } elsif ( $type eq 'ARRAY' ) { if ( @$el ) { push @lines, $line; push @lines, $self->_write_array( $el, $indent + 1, $seen ); } else { $line .= ' []'; push @lines, $line; } } elsif ( $type eq 'HASH' ) { if ( keys %$el ) { push @lines, $line; push @lines, $self->_write_hash( $el, $indent + 1, $seen ); } else { $line .= ' {}'; push @lines, $line; } } else { die "CPAN::Meta::YAML does not support $type references"; } } @lines; } sub _write_hash { my ($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 $indent) . "$name:"; my $type = ref $el; if ( ! $type ) { $line .= ' ' . $self->_write_scalar( $el, $indent + 1 ); push @lines, $line; } elsif ( $type eq 'ARRAY' ) { if ( @$el ) { push @lines, $line; push @lines, $self->_write_array( $el, $indent + 1, $seen ); } else { $line .= ' []'; push @lines, $line; } } elsif ( $type eq 'HASH' ) { if ( keys %$el ) { push @lines, $line; push @lines, $self->_write_hash( $el, $indent + 1, $seen ); } else { $line .= ' {}'; push @lines, $line; } } else { die "CPAN::Meta::YAML does not support $type references"; } } @lines; } # Set error sub _error { $CPAN::Meta::YAML::errstr = $_[1]; undef; } # Retrieve error sub errstr { $CPAN::Meta::YAML::errstr; } ##################################################################### # YAML Compatibility sub Dump { CPAN::Meta::YAML->new(@_)->write_string; } sub Load { my $self = CPAN::Meta::YAML->read_string(@_); unless ( $self ) { Carp::croak("Failed to load YAML document from string"); } if ( wantarray ) { return @$self; } else { # To match YAML.pm, return the last document return $self->[-1]; } } BEGIN { *freeze = *Dump; *thaw = *Load; } sub DumpFile { my $file = shift; CPAN::Meta::YAML->new(@_)->write($file); } sub LoadFile { my $self = CPAN::Meta::YAML->read($_[0]); unless ( $self ) { Carp::croak("Failed to load YAML document from '" . ($_[0] || '') . "'"); } if ( wantarray ) { return @$self; } else { # Return only the last document to match YAML.pm, return $self->[-1]; } } ##################################################################### # Use Scalar::Util if possible, otherwise emulate it BEGIN { eval { require Scalar::Util; *refaddr = *Scalar::Util::refaddr; }; eval <<'END_PERL' if $@; # Failed to load Scalar::Util 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 { local $^W; hex $1 }; bless $_[0], $pkg if defined $pkg; $i; } END_PERL } 1; =pod =head1 NAME CPAN::Meta::YAML - Read and write a subset of YAML for CPAN Meta files =head1 VERSION version 0.003 =head1 SYNOPSIS use CPAN::Meta::YAML; # methods for files $yaml = CPAN::Meta::YAML->read('META.yml'); $yaml->write('MYMETA.yml'); # methods for strings $yaml_text = $yaml->write_string; $yaml = CPAN::Meta::YAML->read_string($yaml_text); # finding the metadata my $meta = $yaml->[0]; # handling errors $yaml->write($file) or die CPAN::Meta::YAML->errstr; =head1 DESCRIPTION This module implements a subset of the YAML specification for use in reading and writing CPAN metadata files like F and F. It should not be used for any other general YAML parsing or generation task. =head1 SUPPORT This module is currently derived from L 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 =head1 SEE ALSO L, L, L =head1 AUTHORS =over 4 =item * Adam Kennedy =item * David Golden =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