💡📝H. G. Muller wrote on Sat, Dec 12, 2020 03:21 PM UTC:
Well, for displaying the game I prefer SAN, as it is the commonly used notation by regular Chess players. I would like the game parser to be as universal as possible, though. At the moment it would not understand formats with multiple hyphens; I assumed that intemediate squares only had to be mentioned with locust captures, and would be preceded by an 'x'. Then only the final leg of a multi-leg move could go to an empty square. But this is wrong; e.g. the Valkyrie of Odin's Rune Chess needs to go to the square where it wants to move the displaced piece to first. So I suppose I should first replace all 'x' in the move by hyphens, and then split by hyphens.
The problem is how to distinguish an intermediate square from the square of origin. When there always was an 'x' in front of intermediate squares, that was easy, as there never is an 'x' between the piece ID and a (possibly partial) square of origin. It would be problematic if there could be a hyphen between piece ID and origin. I guess I could check whether the first square, when it is fully mentioned, contains the mentioned piece. If not, it must have been an intermediate.
I have not decided about how to indicate the position. The method of random seed works, but cannot be used if the game was not generated by the diagram itself. FENs become pretty ugly with multi-letter IDs. And they are a bit overkill, as we don't want to indicate arbitrary positions, but just how the pieces are permutated. E.g. for Chess960 it would be enough to print the back rank. And that is small enough to make it a comma-separated list.
So perhaps the following would be a good solution: the Diagram's shuffle parameter contains piece types. During a raster scan of the board (say a1->h1->h8), any square that contains a piece that occurs in that list in the 'nominal' (= pre-shuffle) start position can potentially get another piece, and you the Diagram then print/reads the piece that actually ended up there. If the shuffle was symmetric you only do that for white pieces.
Well, for displaying the game I prefer SAN, as it is the commonly used notation by regular Chess players. I would like the game parser to be as universal as possible, though. At the moment it would not understand formats with multiple hyphens; I assumed that intemediate squares only had to be mentioned with locust captures, and would be preceded by an 'x'. Then only the final leg of a multi-leg move could go to an empty square. But this is wrong; e.g. the Valkyrie of Odin's Rune Chess needs to go to the square where it wants to move the displaced piece to first. So I suppose I should first replace all 'x' in the move by hyphens, and then split by hyphens.
The problem is how to distinguish an intermediate square from the square of origin. When there always was an 'x' in front of intermediate squares, that was easy, as there never is an 'x' between the piece ID and a (possibly partial) square of origin. It would be problematic if there could be a hyphen between piece ID and origin. I guess I could check whether the first square, when it is fully mentioned, contains the mentioned piece. If not, it must have been an intermediate.
I have not decided about how to indicate the position. The method of random seed works, but cannot be used if the game was not generated by the diagram itself. FENs become pretty ugly with multi-letter IDs. And they are a bit overkill, as we don't want to indicate arbitrary positions, but just how the pieces are permutated. E.g. for Chess960 it would be enough to print the back rank. And that is small enough to make it a comma-separated list.
So perhaps the following would be a good solution: the Diagram's shuffle parameter contains piece types. During a raster scan of the board (say a1->h1->h8), any square that contains a piece that occurs in that list in the 'nominal' (= pre-shuffle) start position can potentially get another piece, and you the Diagram then print/reads the piece that actually ended up there. If the shuffle was symmetric you only do that for white pieces.