add (for chess game)

--[CLASSES]
local tPieces=setmetatable({},{__call=function(t,x,y)
    for num,tPiece in pairs(t) do
        if tPiece.x==x and tPiece.y==y then return tPiece,num end
    end
    return {sym=' '}
end})

board=function()
    return tPieces
end

R=function(x,y,owner)
    owner=owner or false
    return setmetatable({x=x,y=y,col=owner,sym='R',hasMoved=false},{__call=function(t)
        local tOpts={}
        for a=1,t.x-1 do
            if tPieces(t.x-a,t.y).col~=t.col then table.insert(tOpts,{t.x-a,t.y}) end
            if tPieces(t.x-a,t.y).x then break end
        end
        for a=1,8-t.x do
            if tPieces(t.x+a,t.y).col~=t.col then table.insert(tOpts,{t.x+a,t.y}) end
            if tPieces(t.x+a,t.y).x then break end
        end
        for a=1,t.y-1 do
            if tPieces(t.x,t.y-a).col~=t.col then table.insert(tOpts,{t.x,t.y-a}) end
            if tPieces(t.x,t.y-a).x then break end
        end
        for a=1,8-t.y do
            if tPieces(t.x,t.y+a).col~=t.col then table.insert(tOpts,{t.x,t.y+a}) end
            if tPieces(t.x,t.y+a).x then break end
        end
        return tOpts
    end})
end

B=function(x,y,owner)
    owner=owner or false
    return setmetatable({x=x,y=y,col=owner,sym='B',hasMoved=false},{__call=function(t)
        local tOpts={}
        for num=1,math.min(t.x,t.y)-1 do
            if tPieces(t.x-num,t.y-num).col~=t.col then table.insert(tOpts,{t.x-num,t.y-num}) end
            if tPieces(t.x-num,t.y-num).x then break end
        end
        for num=1,math.min(8-t.x,8-t.y) do
            if tPieces(t.x+num,t.y+num).col~=t.col then table.insert(tOpts,{t.x+num,t.y+num}) end
            if tPieces(t.x+num,t.y+num).x then break end
        end
        for num=1,math.min(9-t.x,t.y)-1 do
            if tPieces(t.x+num,t.y-num).col~=t.col then table.insert(tOpts,{t.x+num,t.y-num}) end
            if tPieces(t.x+num,t.y-num).x then break end
        end
        for num=1,math.min(t.x,9-t.y)-1 do
            if tPieces(t.x-num,t.y+num).col~=t.col then table.insert(tOpts,{t.x-num,t.y+num}) end
            if tPieces(t.x-num,t.y+num).x then break end
        end
        return tOpts
    end})
end

Q=function(x,y,owner)
    owner=owner or false
    return setmetatable({x=x,y=y,col=owner,sym='Q',hasMoved=false},{__call=function(t)
        local tOpts={}
        for a=1,t.x-1 do
            if tPieces(t.x-a,t.y).col~=t.col then table.insert(tOpts,{t.x-a,t.y}) end
            if tPieces(t.x-a,t.y).x then break end
        end
        for a=1,8-t.x do
            if tPieces(t.x+a,t.y).col~=t.col then table.insert(tOpts,{t.x+a,t.y}) end
            if tPieces(t.x+a,t.y).x then break end
        end
        for a=1,t.y-1 do
            if tPieces(t.x,t.y-a).col~=t.col then table.insert(tOpts,{t.x,t.y-a}) end
            if tPieces(t.x,t.y-a).x then break end
        end
        for a=1,8-t.y do
            if tPieces(t.x,t.y+a).col~=t.col then table.insert(tOpts,{t.x,t.y+a}) end
            if tPieces(t.x,t.y+a).x then break end
        end
        for num=1,math.min(t.x,t.y)-1 do
            if tPieces(t.x-num,t.y-num).col~=t.col then table.insert(tOpts,{t.x-num,t.y-num}) end
            if tPieces(t.x-num,t.y-num).x then break end
        end
        for num=1,math.min(8-t.x,8-t.y) do
            if tPieces(t.x+num,t.y+num).col~=t.col then table.insert(tOpts,{t.x+num,t.y+num}) end
            if tPieces(t.x+num,t.y+num).x then break end
        end
        for num=1,math.min(9-t.x,t.y)-1 do
            if tPieces(t.x+num,t.y-num).col~=t.col then table.insert(tOpts,{t.x+num,t.y-num}) end
            if tPieces(t.x+num,t.y-num).x then break end
        end
        for num=1,math.min(t.x,9-t.y)-1 do
            if tPieces(t.x-num,t.y+num).col~=t.col then table.insert(tOpts,{t.x-num,t.y+num}) end
            if tPieces(t.x-num,t.y+num).x then break end
        end
        return tOpts
    end})
end

K=function(x,y,owner)
    owner=owner or false
    return setmetatable({x=x,y=y,col=owner,sym='K',hasMoved=false},{__call=function(t)
        local tOpts={}
        for a=-1,1,1 do
            for b=-1,1,1 do
                if not (a==0 and b==0) and t.x+a>0 and t.x+a<=8 and t.y+b>0 and t.y+b<=8 and tPieces(t.x+a,t.y+b).col~=t.col then
                    table.insert(tOpts,{t.x+a,t.y+b})
                end
            end
        end
        return tOpts
    end})
end

H=function(x,y,owner)
    owner=owner or false
    return setmetatable({x=x,y=y,col=owner,sym='H',hasMoved=false},{__call=function(t)
        local tOpts={}
        for num,to in pairs({{t.x+1,t.y+2},{t.x+1,t.y-2},{t.x-1,t.y+2},{t.x-1,t.y-2},{t.x+2,t.y+1},{t.x+2,t.y-1},{t.x-2,t.y+1},{t.x-2,t.y-1}}) do
            if tPieces(unpack(to)).col~=t.col and to[1]<=8 and to[1]>=1 and to[2]<=8 and to[2]>=1 then
                table.insert(tOpts,to)
            end
        end
        return tOpts
    end})
end

P=function(x,y,owner)
    owner=owner or false
    return setmetatable({x=x,y=y,col=owner,sym='P',hasMoved=false},{__call=function(t)
        local tOpts={}
        local target=tPieces(t.x,t.y+(t.col and -1 or 1))
        if not target.x and t.y+(t.col and -1 or 1)>0 and t.y+(t.col and -1 or 1)<=8 then table.insert(tOpts,{t.x,t.y+(t.col and -1 or 1)}) end
        for a=-1,1,2 do
            local target=tPieces(t.x+a,t.y+(t.col and -1 or 1))
            if target.col~=t.col and target.x then table.insert(tOpts,{t.x+a,t.y+(t.col and -1 or 1)}) end
        end
        if not t.hasMoved and not tPieces(t.x,t.y+(t.col and -1 or 1)).x and not tPieces(t.x,t.y+(t.col and -2 or 2)).x and t.y+(t.col and -2 or 2)>0 and t.y+(t.col and -2 or 2)<=8 then table.insert(tOpts,{t.x,t.y+(t.col and -2 or 2)}) end
        return tOpts
    end})
end