QBJS - Chess API

[dbox]

IMHO  you can use Stockfish or any other  chess engines with UCI protocol,(chess engine that uses UCI protocol UCI  protocol for communicating with other programs)

True, but for my purposes, I liked the simplicity of this API.  There is no complicated protocol to negotiate and there are really only a few methods that are needed.

First just use the QBJS Import statement to include the library:

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Import Chess From "https://boxgaming.github.io/qbjs-lib/chess/js-chess-engine.bas"

This will load the API and we can use the following methods to interact with the engine:

Move
Move the piece at a given board location to the specified new location

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If Chess.Move("C2", "C3") Then

    ' The move was successful

Else

    ' An error occurred, probably an invalid move

    Print Chess.LastErrorMessage

End If

AIMove
Let the engine make the next move using the specified difficulty level

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Chess.AIMove 3

Moves
Returns the list of available moves for the piece at the specified board location

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ReDim results(0) As String

results = Chess.Moves("C3")

For i = 1 To UBound(results)

    Print results(i)

Next i

BoardPieces
Returns a map containing the board locations with pieces present.

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Dim pieces() As String

pieces = Chess.BoardPieces

Print "B1: "; pieces("B1")

Print "E8: "; pieces("E8")

Print "G5: "; pieces("G5")

In the standard beginning positions the above would output:

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B1: N
E8: k
G5: 

The only other methods are NewGame, to reset the board for a new game and a few additional functions that return current game state information (IsCheck, IsCheckMate, IsFinished).