1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
package Forest::Tree::Builder::SimpleTextFile;
use Moose;
our $VERSION = '0.09';
our $AUTHORITY = 'cpan:STEVAN';
no warnings 'recursion';
with qw(Forest::Tree::Builder::Callback); # for compatibility with overriding create_new_subtree, otherwise invisible
has fh => (
isa => "FileHandle",
is => "ro",
required => 1,
);
has 'tab_width' => (
is => 'rw',
isa => 'Int',
default => 4
);
has 'parser' => (
is => 'rw',
isa => 'CodeRef',
lazy => 1,
builder => 'build_parser',
);
sub build_parser {
return sub {
my ($self, $line) = @_;
my ($indent, $node) = ($line =~ /^(\s*)(.*)$/);
my $depth = ((length $indent) / $self->tab_width);
return ($depth, $node);
}
}
sub parse_line { $_[0]->parser->(@_) }
sub _build_subtrees {
my $self = shift;
my $cur_children = [];
my @stack;
my $fh = $self->fh;
while ( defined(my $line = <$fh>) ) {
chomp($line);
next if !$line || $line =~ /^#/;
my ($depth, $node, @rest) = $self->parse_line($line);
if ( $depth > @stack ) {
if ( $depth = @stack + 1 ) {
push @stack, $cur_children;
$cur_children = $cur_children->[-1]{children} = [];
} else {
die "Parse Error : the difference between the depth ($depth) and " .
"the tree depth (" . scalar(@stack) . ") is too much (" .
($depth - @stack) . ") at line:\n'$line'";
}
} elsif ( $depth < @stack ) {
while ( $depth < @stack ) {
foreach my $node ( @$cur_children ) {
$node = $self->create_new_subtree(%$node);
}
$cur_children = pop @stack;
}
}
push @$cur_children, { node => $node, @rest };
}
while ( @stack ) {
$_ = $self->create_new_subtree(%$_) for @$cur_children;
$cur_children = pop @stack;
}
return [ map { $self->create_new_subtree(%$_) } @$cur_children ];
}
__PACKAGE__->meta->make_immutable;
no Moose; 1;
__END__
=head1 NAME
Forest::Tree::Builder::SimpleTextFile - Parse trees from indented ASCII files
=head1 SYNOPSIS
use Path::Class;
my $file = file($path);
my $builder = Forest::Tree::Builder::SimpleTextFile->new(
fh => $file->openr,
);
my $tree = $builder->tree;
=head1 DESCRIPTION
This module replaces L<Forest::Tree::Reader::SimpleTextFile> with a declarative
api instead of an imperative one.
=head1 ATTRIBUTES
=over 4
=item fh
The filehandle to read from.
Required.
=item parser
A coderef that parses a single line from C<fh> and returns the node depth and
its value.
Defaults to space indented text. See also L</tab_width>.
=item tab_width
The indentation level for the default parser. Defaults to 4, which means that
four spaces equate to one level of nesting.
=back
=head1 BUGS
All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
=head1 AUTHOR
Yuval Kogman
=head1 COPYRIGHT AND LICENSE
Copyright 2008-2010 Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut
|
