local BLACK = "black"
local WHITE = "white"
local PAWN = "P"
local ROOK = "R"
local KNIGHT = "N"
local BISHOP = "B"
local QUEEN = "Q"
local KING = "K"
local KINGSIDE = 7
local QUEENSIDE = 12
local DEFAULT_BOARD = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR'
local bit32 = bit32 or require('bit32')
--[[ following lines require when running locally - uncomment.
mw = mw or {
ustring = string,
text = {
['split'] = local function(s, pattern)
local res = {}
while true do
local start, finish = s:find(pattern)
if finish and finish > 1 then
local frag = s:sub(1, start - 1)
table.insert(res, frag)
s = s:sub(finish + 1)
else
break
end
end
if #s then table.insert(res, s) end
return res
end,
['trim'] = local function(t)
t = type(t) == 'string' and t:gsub('^%s+', '')
t = t:gsub('%s+$', '')
return t
end
}
}
]]
-- in lua 5.3, unpack is not a first class citizen anymore, but - assign table.unpack
local unpack = unpack or table.unpack
local function apply(f, ...)
res = {}
targ = {...}
for ind = 1, #targ do
res[ind] = f(targ[ind])
end
return unpack(res)
end
local function empty(s)
return not s or mw.text.trim(s) == ''
end
local function falseIfEmpty(s)
return not empty(s) and s
end
local function charToFile(ch)
return falseIfEmpty(ch) and string.byte(ch) - string.byte('a')
end
local function charToRow(ch)
return falseIfEmpty(ch) and tonumber(ch) - 1
end
local function indexToCoords(index)
return index % 8, math.floor(index / 8)
end
local function coordsToIndex(file, row)
return row * 8 + file
end
local function charToPiece(letter)
local piece = mw.ustring.upper(letter)
return piece, piece == letter and WHITE or BLACK
end
local function pieceToChar(piece, color)
return color == WHITE and piece or mw.ustring.lower(piece)
end
local function ambigToIndex(file, row)
if row == nil then return file end
return coordsToIndex(file, row)
end
local function enPasantRow(color)
return color == WHITE and 5 or 2
end
local function sign(a)
return a < 0 and -1
or a > 0 and 1
or 0
end
local function pieceAt(board, fileOrInd, row) -- called with 2 params, fileOrInd is the index, otherwise it's the file.
local letter = board[ambigToIndex(fileOrInd, row)]
if not letter then return end
return charToPiece(letter)
end
local function findPieces(board, piece, color)
local result = {}
local lookFor = pieceToChar(piece, color)
for index = 0, 63 do
local letter = board[index]
if letter == lookFor then table.insert(result, index) end
end
return result
end
local function roadIsClear(board, ind1, ind2)
if ind1 == ind2 then error('call to roadIsClear with identical indices', ind1) end
local file1, row1 = indexToCoords(ind1)
local file2, row2 = indexToCoords(ind2)
if (file1 - file2) * (row1 - row2) * (math.abs(row1 - row2) - math.abs(file1 - file2)) ~= 0 then
error('sent two indices to roadIsClear which are not same row, col, or diagonal: ', ind1, ind2)
end
local hdelta = sign(file2 - file1)
local vdelta = sign(row2 - row1)
local row, file = row1 + vdelta, file1 + hdelta
while row ~= row2 or file ~= file2 do
if pieceAt(board, file, row) then return false end
row = row + vdelta
file = file + hdelta
end
return true
end
local function pawnCanMove(board, color, startFile, startRow, file, row, capture)
local hor, ver = file - startFile, row - startRow
local absVer = math.abs(ver)
if capture then
local ok = hor * hor == 1 and (
color == WHITE and ver == 1 or
color == BLACK and ver == - 1
)
local enpassant = ok and
row == enPasantRow(color) and
pieceAt(board, file, row) == nil
return ok, enpassant
else
if hor ~= 0 then return false end
end
if absVer == 2 then
if not roadIsClear(board, coordsToIndex(startFile, startRow), coordsToIndex(file, row)) then return false end
return color == WHITE and startRow == 1 and ver == 2 or
color == BLACK and startRow == 6 and ver == -2
end
return color == WHITE and ver == 1 or color == BLACK and ver == -1
end
local function canMove(board, start, dest, capture, verbose)
local startFile, startRow = indexToCoords(start)
local file, row = indexToCoords(dest)
local piece, color = pieceAt(board, startFile, startRow)
if piece == PAWN then return pawnCanMove(board, color, startFile, startRow, file, row, capture) end
local dx, dy = math.abs(startFile - file), math.abs(startRow - row)
return piece == KNIGHT and dx * dy == 2
or piece == KING and bit32.bor(dx, dy) == 1
or (
piece == ROOK and dx * dy == 0
or piece == BISHOP and dx == dy
or piece == QUEEN and dx * dy * (dx - dy) == 0
) and roadIsClear(board, start, dest, verbose)
end
local function exposed(board, color) -- only test for queen, rook, bishop.
local king = findPieces(board, KING, color)[1]
for ind = 1, 63 do
local letter = board[ind]
if letter then
local _, pcolor = charToPiece(letter)
if pcolor ~= color and canMove(board, ind, king, true) then
return true
end
end
end
end
local function clone(orig)
local res = {}
for k, v in pairs(orig) do res[k] = v end
return res
end
local function place(board, piece, color, file, row) -- in case of chess960, we have to search
board[ambigToIndex(file, row)] = pieceToChar(piece, color)
return board
end
local function clear(board, file, row)
board[ambigToIndex(file, row)] = nil
return board
end
local function doCastle(board, color, side)
local row = color == WHITE and 0 or 7
local startFile, step = 0, 1
local kingDestFile, rookDestFile = 2, 3
local king = findPieces(board, KING, color)[1]
local rook
if side == KINGSIDE then
startFile, step = 7, -1
kingDestFile, rookDestFile = 6, 5
end
for file = startFile, 7 - startFile, step do
local piece = pieceAt(board, file, row)
if piece == ROOK then
rook = coordsToIndex(file, row)
break
end
end
board = clear(board, king)
board = clear(board, rook)
board = place(board, KING, color, kingDestFile, row)
board = place(board, ROOK, color, rookDestFile, row)
return board
end
local function doEnPassant(board, pawn, file, row)
local _, color = pieceAt(board, pawn)
board = clear(board, pawn)
board = place(board, PAWN, color, file, row)
if row == 5 then board = clear(board, file, 4) end
if row == 2 then board = clear(board, file, 3) end
return board
end
local function generateFen(board)
local res = ''
local offset = 0
for row = 7, 0, -1 do
for file = 0, 7 do
piece = board[coordsToIndex(file, row)]
res = res .. (piece or '1')
end
if row > 0 then res = res .. '/' end
end
return mw.ustring.gsub(res, '1+', function( s ) return #s end )
end
local function findCandidate(board, piece, color, oldFile, oldRow, file, row, capture, notation)
local enpassant = {}
local candidates, newCands = findPieces(board, piece, color), {} -- all black pawns or white kings etc.
if oldFile or oldRow then
local newCands = {}
for _, cand in ipairs(candidates) do
local file, row = indexToCoords(cand)
if file == oldFile then table.insert(newCands, cand) end
if row == oldRow then table.insert(newCands, cand) end
end
candidates, newCands = newCands, {}
end
local dest = coordsToIndex(file, row)
for _, candidate in ipairs(candidates) do
local can
can, enpassant[candidate] = canMove(board, candidate, dest, capture)
if can then table.insert(newCands, candidate) end
end
candidates, newCands = newCands, {}
if #candidates == 1 then return candidates[1], enpassant[candidates[1]] end
if #candidates == 0 then
error('could not find a piece that can execute ' .. notation)
end
-- we have more than one candidate. this means that all but one of them can't really move, b/c it will expose the king
-- test for it by creating a new board with this candidate removed, and see if the king became exposed
for _, candidate in ipairs(candidates) do
local cloneBoard = clone(board) -- first, clone the board
cloneBoard = clear(cloneBoard, candidate) -- now, remove the piece
if not exposed(cloneBoard, color) then table.insert(newCands, candidate) end
end
candidates, newCands = newCands, {}
if #candidates == 1 then return candidates[1] end
error(mw.ustring.format('too many (%d, expected 1) pieces can execute %s at board %s', #candidates, notation, generateFen(board)))
end
local function move(board, notation, color)
local endGame = {['1-0']=true, ['0-1']=true, ['1/2-1/2']=true, ['*']=true}
local cleanNotation = mw.ustring.gsub(notation, '[!?+# ]', '')
if cleanNotation == 'O-O' then
return doCastle(board, color, KINGSIDE)
end
if cleanNotation == 'O-O-O' then
return doCastle(board, color, QUEENSIDE)
end
if endGame[cleanNotation] then
return board, true
end
local pattern = '([RNBKQ]?)([a-h]?)([1-8]?)(x?)([a-h])([1-8])(=?[RNBKQ]?)'
local _, _, piece, oldFile, oldRow, isCapture, file, row, promotion = mw.ustring.find(cleanNotation, pattern)
oldFile, file = apply(charToFile, oldFile, file)
oldRow, row = apply(charToRow, oldRow, row)
piece = falseIfEmpty(piece) or PAWN
promotion = falseIfEmpty(promotion)
isCapture = falseIfEmpty(isCapture)
local candidate, enpassant = findCandidate(board, piece, color, oldFile, oldRow, file, row, isCapture, notation) -- findCandidates should panic if # != 1
if enpassant then
return doEnPassant(board, candidate, file, row)
end
board[coordsToIndex(file, row)] = promotion and pieceToChar(promotion:sub(-1), color) or board[candidate]
board = clear(board, candidate)
return board
end
local function create( fen )
-- converts FEN notation to 64 entry array of positions. copied from enwiki Module:Chessboard (in some distant past i prolly wrote it)
local res = {}
local row = 8
-- Loop over rows, which are delimited by /
for srow in string.gmatch( "/" .. fen, "/%w+" ) do
srow = srow:sub(2)
row = row - 1
local ind = row * 8
-- Loop over all letters and numbers in the row
for piece in srow:gmatch( "%w" ) do
if piece:match( "%d" ) then -- if a digit
ind = ind + piece
else -- not a digit
res[ind] = piece
ind = ind + 1
end
end
end
return res
end
local function processMeta(grossMeta)
res = {}
-- process grossMEta here
for item in mw.ustring.gmatch(grossMeta or '', '%[([^%]]*)%]') do
key, val = item:match('([^"]+)"([^"]*)"')
if key and val then
res[mw.text.trim(key)] = mw.text.trim(val) -- add mw.text.trim()
else
error('strange item detected: ' .. item .. #items) -- error later
end
end
return res
end
local function analyzePgn(pgn)
local grossMeta = pgn:match('%[(.*)%]') -- first open to to last bracket
pgn = string.gsub(pgn, '%[(.*)%]', '')
local steps = mw.text.split(pgn, '%s*%d+%.%s*')
local moves = {}
for _, step in ipairs(steps) do
if mw.ustring.len(mw.text.trim(step)) then
ssteps = mw.text.split(step, '%s+')
for _, sstep in ipairs(ssteps) do
if sstep and not mw.ustring.match(sstep, '^%s*$') then table.insert(moves, sstep) end
end
end
end
return processMeta(grossMeta), moves
end
local function pgn2fen(pgn)
local metadata, notationList = analyzePgn(pgn)
local fen = metadata.fen or DEFAULT_BOARD
local board = create(fen)
local res = {fen}
local colors = {BLACK, WHITE}
for step, notation in ipairs(notationList) do
local color = colors[step % 2 + 1]
board = move(board, notation, color)
local fen = generateFen(board)
table.insert(res, fen)
end
return res, metadata
end
return {
pgn2fen = pgn2fen,
main = function(pgn)
local res, metadata = pgn2fen(pgn)
return metadata, res
end,
}
Modül belgelemesi[oluştur]