Reader.pm.svn-base
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上传日期:2018-11-18
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文件大小:10k
- package Data::YAML::Reader;
- use strict;
- use warnings;
- use Carp;
- use vars qw{$VERSION};
- $VERSION = '0.0.5';
- # TODO:
- # Handle blessed object syntax
- # Printable characters for escapes
- my %UNESCAPES = (
- z => "x00",
- a => "x07",
- t => "x09",
- n => "x0a",
- v => "x0b",
- f => "x0c",
- r => "x0d",
- e => "x1b",
- '\' => '\',
- );
- my $QQ_STRING = qr{ " (?:\. | [^"])* " }x;
- my $HASH_LINE = qr{ ^ ($QQ_STRING|S+) s* : (?: s+ (.+?) s* )? $ }x;
- my $IS_HASH_KEY = qr{ ^ [w'"] }x;
- my $IS_END_YAML = qr{ ^ [.][.][.] s* $ }x;
- my $IS_QQ_STRING = qr{ ^ $QQ_STRING $ }x;
- # Create an empty Data::YAML::Reader object
- sub new {
- my $class = shift;
- bless {}, $class;
- }
- sub _make_reader {
- my $self = shift;
- my $obj = shift;
- croak "Must have something to read from"
- unless defined $obj;
- if ( my $ref = ref $obj ) {
- if ( 'CODE' eq $ref ) {
- return $obj;
- }
- elsif ( 'ARRAY' eq $ref ) {
- return sub { shift @$obj };
- }
- elsif ( 'SCALAR' eq $ref ) {
- return $self->_make_reader( $$obj );
- }
- elsif ( 'GLOB' eq $ref || 'IO::Handle' eq $ref ) {
- return sub {
- my $line = <$obj>;
- chomp $line if defined $line;
- return $line;
- };
- }
- croak "Don't know how to read $ref";
- }
- else {
- my @lines = split( /n/, $obj );
- return sub { shift @lines };
- }
- }
- sub read {
- my $self = shift;
- my $obj = shift;
- $self->{reader} = $self->_make_reader( $obj );
- $self->{capture} = [];
- #聽Prime the reader
- $self->_next;
- my $doc = $self->_read;
- # The terminator is mandatory otherwise we'd consume a line from the
- # iterator that doesn't belong to us. If we want to remove this
- # restriction we'll have to implement look-ahead in the iterators.
- # Which might not be a bad idea.
- my $dots = $self->_peek;
- croak "Missing '...' at end of YAML"
- unless $dots =~ $IS_END_YAML;
- delete $self->{reader};
- delete $self->{next};
- return $doc;
- }
- sub get_raw {
- my $self = shift;
- if ( defined( my $capture = $self->{capture} ) ) {
- return join( "n", @$capture ) . "n";
- }
- return '';
- }
- sub _peek {
- my $self = shift;
- return $self->{next} unless wantarray;
- my $line = $self->{next};
- $line =~ /^ (s*) (.*) $ /x;
- return ( $2, length $1 );
- }
- sub _next {
- my $self = shift;
- croak "_next called with no reader"
- unless $self->{reader};
- my $line = $self->{reader}->();
- $self->{next} = $line;
- push @{ $self->{capture} }, $line;
- }
- sub _read {
- my $self = shift;
- my $line = $self->_peek;
- # Do we have a document header?
- if ( $line =~ /^ --- (?: s* (.+?) s* )? $/x ) {
- $self->_next;
- return $self->_read_scalar( $1 ) if defined $1; # Inline?
- my ( $next, $indent ) = $self->_peek;
- if ( $next =~ /^ - /x ) {
- return $self->_read_array( $indent );
- }
- elsif ( $next =~ $IS_HASH_KEY ) {
- return $self->_read_hash( $next, $indent );
- }
- elsif ( $next =~ $IS_END_YAML ) {
- croak "Premature end of YAML";
- }
- else {
- croak "Unsupported YAML syntax: '$next'";
- }
- }
- else {
- croak "YAML document header not found";
- }
- }
- # Parse a double quoted string
- sub _read_qq {
- my $self = shift;
- my $str = shift;
- unless ( $str =~ s/^ " (.*?) " $/$1/x ) {
- die "Internal: not a quoted string";
- }
- $str =~ s/\"/"/gx;
- $str =~ s/ \ ( [tartan\favez] | x([0-9a-fA-F]{2}) )
- / (length($1) > 1) ? pack("H2", $2) : $UNESCAPES{$1} /gex;
- return $str;
- }
- # Parse a scalar string to the actual scalar
- sub _read_scalar {
- my $self = shift;
- my $string = shift;
- return undef if $string eq '~';
- if ( $string eq '>' || $string eq '|' ) {
- my ( $line, $indent ) = $self->_peek;
- die "Multi-line scalar content missing" unless defined $line;
- my @multiline = ($line);
- while (1) {
- $self->_next;
- my ( $next, $ind ) = $self->_peek;
- last if $ind < $indent;
- push @multiline, $next;
- }
- return join( ( $string eq '>' ? ' ' : "n" ), @multiline ) . "n";
- }
- if ( $string =~ /^ ' (.*) ' $/x ) {
- ( my $rv = $1 ) =~ s/''/'/g;
- return $rv;
- }
- if ( $string =~ $IS_QQ_STRING ) {
- return $self->_read_qq($string);
- }
- if ( $string =~ /^['"]/ ) {
- # A quote with folding... we don't support that
- die __PACKAGE__ . " does not support multi-line quoted scalars";
- }
- # Regular unquoted string
- return $string;
- }
- sub _read_nested {
- my $self = shift;
- my ( $line, $indent ) = $self->_peek;
- if ( $line =~ /^ -/x ) {
- return $self->_read_array( $indent );
- }
- elsif ( $line =~ $IS_HASH_KEY ) {
- return $self->_read_hash( $line, $indent );
- }
- else {
- croak "Unsupported YAML syntax: '$line'";
- }
- }
- # Parse an array
- sub _read_array {
- my ( $self, $limit ) = @_;
- my $ar = [];
- while ( 1 ) {
- my ( $line, $indent ) = $self->_peek;
- last if $indent < $limit || !defined $line || $line =~ $IS_END_YAML;
- if ( $indent > $limit ) {
- croak "Array line over-indented";
- }
- if ( $line =~ /^ (- s+) S+ s* : (?: s+ | $ ) /x ) {
- $indent += length $1;
- $line =~ s/-s+//;
- push @$ar, $self->_read_hash( $line, $indent );
- }
- elsif ( $line =~ /^ - s* (.+?) s* $/x ) {
- croak "Unexpected start of YAML" if $line =~ /^---/;
- $self->_next;
- push @$ar, $self->_read_scalar( $1 );
- }
- elsif ( $line =~ /^ - s* $/x ) {
- $self->_next;
- push @$ar, $self->_read_nested;
- }
- elsif ( $line =~ $IS_HASH_KEY ) {
- $self->_next;
- push @$ar, $self->_read_hash( $line, $indent, );
- }
- else {
- croak "Unsupported YAML syntax: '$line'";
- }
- }
- return $ar;
- }
- sub _read_hash {
- my ( $self, $line, $limit ) = @_;
- my $indent;
- my $hash = {};
- while ( 1 ) {
- croak "Badly formed hash line: '$line'"
- unless $line =~ $HASH_LINE;
- my ( $key, $value ) = ( $self->_read_scalar( $1 ), $2 );
- $self->_next;
- if ( defined $value ) {
- $hash->{$key} = $self->_read_scalar( $value );
- }
- else {
- $hash->{$key} = $self->_read_nested;
- }
- ( $line, $indent ) = $self->_peek;
- last if $indent < $limit || !defined $line || $line =~ $IS_END_YAML;
- }
- return $hash;
- }
- 1;
- __END__
- =head1 NAME
- Data::YAML::Reader - Parse YAML created by Data::YAML::Writer
- =head1 VERSION
- This document describes Data::YAML::Reader version 0.0.5
- =head1 SYNOPSIS
- use Data::YAML::Reader;
- my $yr = Data::YAML::Reader->new;
-
- # Read from an array...
- my $from_array = $yr->read( @some_array );
-
- # ...an open file handle...
- my $from_handle = $yr->read( $some_file );
-
- # ...a string containing YAML...
- my $from_string = $yr->read( $some_string );
-
- # ...or a closure
- my $from_code = $yr->read( sub { return get_next_line() } );
- =head1 DESCRIPTION
- In the spirit of L<YAML::Tiny> this is a lightweight, dependency-free
- YAML reader. While C<YAML::Tiny> is designed principally for working
- with configuration files C<Data::YAML> concentrates on the transparent
- round-tripping of YAML serialized Perl data structures.
- The syntax accepted by C<Data::YAML::Reader> is a subset of YAML.
- Specifically it is the same subset of YAML that L<Data::YAML::Writer>
- produces. See L<Data::YAML> for more information.
- =head1 INTERFACE
- =over
- =item C<< new >>
- Creates and returns an empty C<Data::YAML::Reader> object. No options may be passed.
- =item C<< read( $source ) >>
- Read YAML and return the data structure it represents. The YAML data may be supplied by a
- =over
- =item * scalar string containing YAML source
- =item * the handle of an open file
- =item * a reference to an array of lines
- =item * a code reference
- =back
- In the case of a code reference a subroutine (most likely a closure)
- that returns successive lines of YAML must be supplied. Lines should
- have no trailing newline. When the YAML is exhausted the subroutine must
- return undef.
- Returns the data structure (specifically either a scalar, hash ref or
- array ref) that results from decoding the YAML.
- =item C<< get_raw >>
- Return the raw YAML source from the most recent C<read>.
- =back
- =head1 BUGS AND LIMITATIONS
- No bugs have been reported.
- Please report any bugs or feature requests to
- C<data-yaml@rt.cpan.org>, or through the web interface at
- L<http://rt.cpan.org>.
- =head1 SEE ALSO
- L<YAML::Tiny>, L<YAML>, L<YAML::Syck>, L<Config::Tiny>, L<CSS::Tiny>
- =head1 AUTHOR
- Andy Armstrong C<< <andy@hexten.net> >>
- Adam Kennedy wrote L<YAML::Tiny> which provided the template and many of
- the YAML matching regular expressions for this module.
- =head1 LICENCE AND COPYRIGHT
- Copyright (c) 2007, Andy Armstrong C<< <andy@hexten.net> >>. All rights reserved.
- This module is free software; you can redistribute it and/or
- modify it under the same terms as Perl itself. See L<perlartistic>.
- =head1 DISCLAIMER OF WARRANTY
- BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
- FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
- OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
- PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
- EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
- ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
- YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
- NECESSARY SERVICING, REPAIR, OR CORRECTION.
- IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
- WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
- REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
- LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
- OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
- THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
- RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
- FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
- SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
- SUCH DAMAGES.