mathlib-demo.lean:261:40
Expected type
⊢ Color
All Messages (13)
mathlib-demo.lean:98:80

unexpected token 'def'; expected term

mathlib-demo.lean:101:82

unexpected token 'def'; expected term

mathlib-demo.lean:126:80

unexpected token 'def'; expected term

mathlib-demo.lean:129:69

unexpected token 'end'; expected term

mathlib-demo.lean:146:58

unexpected token 'end'; expected term

mathlib-demo.lean:157:53

unexpected token 'partial'; expected term

mathlib-demo.lean:161:48

unexpected token 'def'; expected term

mathlib-demo.lean:164:63

unexpected token 'end'; expected term

mathlib-demo.lean:173:38

unexpected token 'def'; expected term

mathlib-demo.lean:178:27

failed to synthesize
  OfNat String.Pos 1
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
  String.Pos
due to the absence of the instance above
Additional diagnostic information may be available using the `set_option diagnostics true` command.

mathlib-demo.lean:212:46

unexpected token 'end'; expected '{', identifier or term

mathlib-demo.lean:236:20

unknown constant 'IO.getLine'

mathlib-demo.lean:237:21

invalid field notation, type is not of the form (C ...) where C is a constant
  moveStr
has type
  ?m.10952 x✝¹ x✝



import Std
open Std
open IO

/- ======================== Board Representation ========================= -/

inductive PieceType
  | King
  | Queen
  | Rook
  | Bishop
  | Knight
  | Pawn
  deriving Repr, BEq, Inhabited, DecidableEq

inductive Color
  | White
  | Black
  deriving Repr, BEq, Inhabited, DecidableEq

instance : ToString Color where
  toString
    | Color.White => "White"
    | Color.Black => "Black"

structure Piece where
  ptype : PieceType
  color : Color
  deriving Repr, BEq, Inhabited

def Board := Array (Array (Option Piece))

def initialBoard : Board :=
  let emptyRow := Array.mkArray 8 none
  let whitePawns := Array.mkArray 8 (some { ptype := .Pawn, color := .White })
  let blackPawns := Array.mkArray 8 (some { ptype := .Pawn, color := .Black })
  let whiteBackRow :=
    #[ some { ptype := .Rook, color := .White },
       some { ptype := .Knight, color := .White },
       some { ptype := .Bishop, color := .White },
       some { ptype := .Queen, color := .White },
       some { ptype := .King, color := .White },
       some { ptype := .Bishop, color := .White },
       some { ptype := .Knight, color := .White },
       some { ptype := .Rook, color := .White } ]
  let blackBackRow :=
    #[ some { ptype := .Rook, color := .Black },
       some { ptype := .Knight, color := .Black },
       some { ptype := .Bishop, color := .Black },
       some { ptype := .Queen, color := .Black },
       some { ptype := .King, color := .Black },
       some { ptype := .Bishop, color := .Black },
       some { ptype := .Knight, color := .Black },
       some { ptype := .Rook, color := .Black } ]
  #[ whiteBackRow,
     whitePawns,
     emptyRow,
     emptyRow,
     emptyRow,
     emptyRow,
     blackPawns,
     blackBackRow ]

namespace BoardFunctions

def getPiece (board : Board) (x y : Nat) : Option Piece :=
  if x < 8 ∧ y < 8 then
    let row := board.get! x
    row.get! y
  else
    none

def setPiece (board : Board) (x y : Nat) (piece : Option Piece) : Board :=
  if x < 8 ∧ y < 8 then
    let row := board.get! x
    let newRow := row.set! y piece
    board.set! x newRow
  else
    board

end BoardFunctions

/- ============================ Move Generation =========================== -/

structure Move where
  fromX : Nat
  fromY : Nat
  toX   : Nat
  toY   : Nat
  promotion : Option PieceType := none
  deriving Repr, BEq

namespace MoveGeneration

def onBoard (x y : Int) : Bool :=
  x ≥ 0 ∧ x < 8 ∧ y ≥ 0 ∧ y < 8

def generatePawnMoves (board : Board) (x y : Nat) (piece : Piece) : List Move :=
  -- Function body as previously defined

def generateKnightMoves (board : Board) (x y : Nat) (piece : Piece) : List Move :=
  -- Function body as previously defined

def generateSlidingMoves (board : Board) (x y : Nat) (piece : Piece) (directions : List (Int × Int)) : List Move :=
  directions.foldl (fun moves (dx, dy) =>
    let moves := Id.run do
      let mut nx := Int.ofNat x + dx
      let mut ny := Int.ofNat y + dy
      let mut dirMoves : List Move := []
      while onBoard nx ny do
        let targetX := Int.toNat nx
        let targetY := Int.toNat ny
        match BoardFunctions.getPiece board targetX targetY with
        | some targetPiece =>
          if targetPiece.color ≠ piece.color then
            dirMoves := dirMoves ++ [{ fromX := x, fromY := y, toX := targetX, toY := targetY }]
          break
        | none =>
          dirMoves := dirMoves ++ [{ fromX := x, fromY := y, toX := targetX, toY := targetY }]
          nx := nx + dx
          ny := ny + dy
      return moves ++ dirMoves
    moves
  ) []

def generateKingMoves (board : Board) (x y : Nat) (piece : Piece) : List Move :=
  -- Function body as previously defined

def generateLegalMoves (board : Board) (color : Color) : List Move :=
  -- Function body as previously defined

end MoveGeneration

/- =========================== Position Evaluation ======================== -/

namespace Evaluation

def pieceValue : PieceType → Int
  | .Pawn   => 1
  | .Knight => 3
  | .Bishop => 3
  | .Rook   => 5
  | .Queen  => 9
  | .King   => 0

def evaluateBoard (board : Board) (color : Color) : Int :=
  -- Function body as previously defined

end Evaluation

/- ===================== Search and Decision Making ======================= -/

namespace Search

open MoveGeneration Evaluation

def makeMove (board : Board) (move : Move) : Board :=
  -- Function body as previously defined

partial def minimax (board : Board) (depth : Nat) (alpha beta : Int)
    (maximizing : Bool) (color : Color) : Int :=
  -- Function body as previously defined

def decideMove (board : Board) (color : Color) : Option Move :=
  -- Function body as previously defined

end Search

/- ============================ User Interface ============================ -/

namespace UI

def coordToStr (x y : Nat) : String :=
  -- Function body as previously defined

def strToCoord (s : String) : Option (Nat × Nat) :=
  if s.length ≥ 2 then
    match s.get? 0, s.get? 1 with
    | some file, some rank =>
      let files : Array Char := #['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
      let ranks : Array Char := #['1', '2', '3', '4', '5', '6', '7', '8']
      let yOpt := files.indexOf? file
      let xOpt := ranks.indexOf? rank
      match xOpt, yOpt with
      | some x_rev, some y =>
        some (7 - x_rev, y)
      | _, _ => none
    | _, _ => none
  else
    none

def parseMove (s : String) (board : Board) (color : Color) : Option Move :=
  let s := s.trim
  if s.length < 4 then none
  else
    let fromStr := s.take 2
    let toStr := s.drop 2 |>.take 2
    match strToCoord fromStr, strToCoord toStr with
    | some (fromX, fromY), some (toX, toY) =>
      match BoardFunctions.getPiece board fromX fromY with
      | some piece =>
        if piece.color == color then
          let move := { fromX := fromX, fromY := fromY, toX := toX, toY := toY }
          let legalMoves := MoveGeneration.generateLegalMoves board color
          if legalMoves.contains move then
            some move
          else none
        else none
      | none => none
    | _, _ => none

def printBoard (board : Board) : IO Unit := do
  -- Function body as previously defined

end UI

/- ============================== Game Logic ============================== -/

namespace Game

open UI
open Search

def isGameOver (board : Board) (color : Color) : Bool :=
  MoveGeneration.generateLegalMoves board color |>.isEmpty

partial def gameLoop (board : Board) (currentColor : Color) : IO Unit := do
  if isGameOver board currentColor then
    IO.println s!"Game over! {currentColor} has no legal moves."
    let winner := if currentColor == Color.White then "Black" else "White"
    IO.println s!"{winner} wins!"
  else
    if currentColor == Color.White then
      UI.printBoard board
      IO.println "Your move (e.g., e2e4):"
      let moveStr ← IO.getLine
      let moveStr := moveStr.trim
      match UI.parseMove moveStr board Color.White with
      | some move =>
        let newBoard := makeMove board move
        gameLoop newBoard Color.Black
      | none =>
        IO.println "Invalid move. Please try again."
        gameLoop board currentColor
    else
      IO.println "AI is thinking..."
      match decideMove board Color.Black with
      | some move =>
        IO.println s!"AI moves from {UI.coordToStr move.fromX move.fromY} to {UI.coordToStr move.toX move.toY}"
        let newBoard := makeMove board move
        gameLoop newBoard Color.White
      | none =>
        IO.println "AI has no legal moves. You win!"
        return

end Game

/- =========================== Main Entry Point =========================== -/

def main : IO Unit := do
  Game.gameLoop initialBoard Color.White