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Games::Go::Sgf2Dg::Dg2SL - Perl extension to convert Games::Go::Sgf2Dg::Diagrams to Sensei's Library format


use Games::Go::Sgf2Dg::Dg2SL

 my $dg2sl = B<Games::Go::Sgf2Dg::Dg2SL-E<gt>new> (options);
 my $sl = $dg2sl->convertDiagram($diagram);


A Games::Go::Sgf2Dg::Dg2SL object converts a Games::Go::Sgf2Dg::Diagram object into Sensei's Library diagrams (see

Sensei's Library diagrams only support move numbers from 1-10, so make sure you call sgf2dg with arguments that specify a maximum of 10 moves per diagram and starting each diagram with move number 1. Example:

  sgf2dg -converter SL -m 10 -n foo.sgf

Sensei's Library also doesn't support labelled stones.

An initial setup diagram is printed if the initial board isn't empty and doesn't have a handicap setup - i.e., only black stones, all of which are on hoshi points.

Diagrams' extents are limited to the stones actually played, plus a margin. That is, if there are only stones in one corner, only that corner is printed, not the whole diagram. This is useful for analyses of local positions, but if the first ten moves of a real game are all in one corner - however unlikely that may be -, it would produce undesirable results.


my $dg2sl = Games::Go::Sgf2Dg::Dg2SL->new (?options?)

A new Games::Go::Sgf2Dg::Dg2SL takes the following options:

boardSize => number

Sets the size of the board.

Default: 19

coords => true | false

Generates a coordinate grid.

Default: false

topLine => number (Default: 1)
bottomLine => number (Default: 19)
leftLine => number (Default: 1)
rightLine => number (Default: 19)

The edges of the board that should be displayed. Any portion of the board that extends beyond these numbers is not included in the output.

diaCoords => sub { # convert $x, $y to Games::Go::Sgf2Dg::Diagram coordinates }

This callback defines a subroutine to convert coordinates from $x, $y to whatever coordinates are used in the Games::Go::Sgf2Dg::Diagram object. The default diaCoords converts 1-based $x, $y to the same coordinates used in SGF format files. You only need to define this if you're using a different coordinate system in the Diagram.

Default: sub { my ($x, $y) = @_; $x = chr($x - 1 + ord('a')); # convert 1 to 'a', etc $y = chr($y - 1 + ord('a')); return "$x$y"; }, # concatenate two letters

See also the diaCoords method below.

file => 'filename' | $descriptor | \$string | \@array

If file is defined, the Sensei's Library diagram is dumped into the target. The target can be any of:


The filename will be opened using IO::File->new. The filename should include the '>' or '>>' operator as described in 'perldoc IO::File'. The Sensei's Library diagram is written into the file.


A file descriptor as returned by IO::File->new, or a \*FILE descriptor. The Sensei's Library diagram is written into the file.

reference to a string scalar

The Sensei's Library diagram is concatenated to the end of the string.

reference to an array

The Sensei's Library diagram is split on "\n" and each line is pushed onto the array.

Default: undef

A user defined subroutine to replace the default printing method. This callback is called from the print method (below) with the reference to the Dg2SL object and a list of lines that are part of the Sensei's Library diagram lines.


$dg2sl->configure (option => value, ?...?)

Change Dg2SL options from values passed at new time.

my $coord = $dg2mp->diaCoords ($x, $y)

Provides access to the diaCoords option (see above). Returns coordinates in the converter's coordinate system for board coordinates ($x, $y). For example, to get a specific intersection structure:

    my $int = $diagram->get($dg2mp->diaCoords(3, 4));
$dg2sl->print ($text ? , ... ?)

prints the input $text directly to file as defined at new time. Whether or not file was defined, print accumulates the $text for later retrieval with converted.

my $sl = $dg2sl->converted ($replacement)

Returns the entire Sensei's Library diagram converted so far for the Dg2SL object. If $replacement is defined, the accumulated Sensei's Library is replaced by $replacement.

$dg2sl->comment ($comment ? , ... ?)

Inserts the comment character (which is nothing for Sensei's Library) in front of each line of each comment and prints it to file.

my $dg2sl->convertDiagram ($diagram)

Converts a Games::Go::Sgf2Dg::Diagram into Sensei's Library. If file was defined in the new method, the Sensei's Library is dumped into the file. In any case, the Sensei's Library is returned as a string scalar.

my $sl = $dg2sl->convertText ($text)

Converts $text into Sensei's Library code - gee, that's not very hard. In fact, this method simply returns whatever is passed to it. This is really just a place-holder for more complicated converters.

Returns the converted text.

$title = $dg2sl->convertGameProps (\%sgfHash)

convertGameProps takes a reference to a hash of properties as extracted from an SGF file. Each hash key is a property ID and the hash value is a reference to an array of property values: $hash->{propertyId}->[values]. The following SGF properties are recognized:

GN GameName
EV EVent
RO ROund
PW PlayerWhite
WR WhiteRank
PB PlayerBlack
BR BlackRank
PC PlaCe
RU RUles
OT OverTime (byo-yomi)
RE REsult
AN ANnotator
SO Source
US USer (entered by)
GC GameComment

Both long and short property names are recognized, and all unrecognized properties are ignored with no warnings. Note that these properties are all intended as game-level notations.


prints any final text to the diagram (currently none) and closes the dg2sl object. Also closes file if appropriate.



Script to convert SGF format files to Go diagrams


Seems likely.


Marcel Gruenauer, <<gt>


Copyright (C) 2007 by Marcel Gruenauer.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.5 or, at your option, any later version of Perl 5 you may have available.