Export FEN position for a given move

[mdallastella]

Return the FEN notation for a given half-move coordinate.

Given a PGN with 1. e4 e5 2. Nf3 Nc6

Example (pseudo code):

user> (fen-position :white 2 parsed-pgn)
"rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R b KQkq -"

See https://en.wikipedia.org/wiki/Forsyth–Edwards_Notation

[erjoalgo]

Hello. This feature would be very useful, has it been implemented?

[mdallastella]

Hello @erjoalgo, unfortunately no, this feature hasn't been implemented.

To make it work, a chessboard representation should be kept in memory, so the library can simulate all the moves and return a FEN string.

We should also keep in mind that a FEN string also report castling availability and en passant target square, so the library also needs to calculate possible moves… Not as simple as it sounds…

Let me know if you're interested in this ticket.

[erjoalgo]

https://github.com/wolfraam/chess-game I'm integrating this library, which does the heavy lifting in terms of keeping track of game state and listing legal moves. Perhaps the best option to provide this feature would be to use chess-game internally, and this would avoid duplicating effort.