[Shogi] move shogi_utils.py to experimental (#1274)

pgx/_src/dwg/shogi.py

@@ -5,7 +5,7 @@
 
 def _make_shogi_dwg(dwg, state: ShogiState, config):  # noqa: C901
     if state._x.turn == 1:
-        from pgx.shogi import _flip
+        from pgx._src.games.shogi import _flip
 
         state = ShogiState(_x=_flip(state._x))  # type: ignore
     # fmt: off

pgx/_src/shogi_utils.py → pgx/experimental/shogi.py

@@ -12,15 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
 import numpy as np
 import jax
-import jax.numpy as jnp
-import numpy as np
+from pgx._src.games.shogi import _flip, Game, GameState
+from pgx.shogi import State
 
 
-def _to_sfen(state):
+def to_sfen(state):
     """Convert state into sfen expression.
 
     - Board
@@ -37,8 +35,9 @@ def _to_sfen(state):
 
     """
     # NOTE: input must be flipped if white turn
+    state = state if state._x.turn % 2 == 0 else state.replace(_x=_flip(state._x))  # type: ignore
 
-    pb = jnp.rot90(state._x.board.reshape((9, 9)), k=3)
+    pb = np.rot90(state._x.board.reshape((9, 9)), k=3)
     sfen = ""
     # fmt: off
     board_char_dir = ["", "P", "L", "N", "S", "B", "R", "G", "K", "+P", "+L", "+N", "+S", "+B", "+R", "p", "l", "n", "s", "b", "r", "g", "k", "+p", "+l", "+n", "+s", "+b", "+r"]
@@ -69,7 +68,7 @@ def _to_sfen(state):
     else:
         sfen += "w "
     # Hand (prisoners)
-    if jnp.all(state._x.hand == 0):
+    if np.all(state._x.hand == 0):
         sfen += "-"
     else:
         for i in range(2):
@@ -85,14 +84,25 @@ def _to_sfen(state):
     return sfen
 
 
-def _from_sfen(sfen):
+@jax.jit
+def _from_board(turn, piece_board, hand):
+    """Mainly for debugging purpose.
+    terminated, reward, and current_player are not changed"""
+    state = State(_x=GameState(turn=turn, board=piece_board, hand=hand))  # type: ignore
+    # fmt: off
+    state = jax.lax.cond(turn % 2 == 1, lambda: state.replace(_x=_flip(state._x)), lambda: state)  # type: ignore
+    # fmt: on
+    return state.replace(legal_action_mask=Game().legal_action_mask(state._x))  # type: ignore
+
+
+def from_sfen(sfen):
     # fmt: off
     board_char_dir = ["P", "L", "N", "S", "B", "R", "G", "K", "", "", "", "", "", "", "p", "l", "n", "s", "b", "r", "g", "k"]
     hand_char_dir = ["P", "L", "N", "S", "B", "R", "G", "p", "l", "n", "s", "b", "r", "g"]
     # fmt: on
     board, turn, hand, step_count = sfen.split()
     board_ranks = board.split("/")
-    piece_board = jnp.zeros(81, dtype=jnp.int32)
+    piece_board = np.zeros(81, dtype=np.int32)
     for i in range(9):
         file = board_ranks[i]
         rank = []
@@ -109,17 +119,18 @@ def _from_sfen(sfen):
                 rank.append(piece)
                 piece = 0
         for j in range(9):
-            piece_board = piece_board.at[9 * i + j].set(rank[j])
-    s_hand = jnp.zeros(14, dtype=jnp.int32)
+            piece_board[9 * i + j] = rank[j]
+    s_hand = np.zeros(14, dtype=np.int32)
     if hand != "-":
         num_piece = 1
         for char in hand:
             if char.isdigit():
                 num_piece = int(char)
             else:
-                s_hand = s_hand.at[hand_char_dir.index(char)].set(num_piece)
+                s_hand[hand_char_dir.index(char)] = num_piece
                 num_piece = 1
-    piece_board = jnp.rot90(piece_board.reshape((9, 9)), k=1).flatten()
-    hand = jnp.reshape(s_hand, (2, 7))
-    turn = jnp.int32(0) if turn == "b" else jnp.int32(1)
-    return turn, piece_board, hand, int(step_count) - 1
+    piece_board = np.rot90(piece_board.reshape((9, 9)), k=1).flatten()
+    hand = np.reshape(s_hand, (2, 7))
+    turn = 0 if turn == "b" else 1
+    turn, piece_board, hand, step_count = turn, piece_board, hand, int(step_count) - 1
+    return _from_board(turn, piece_board, hand).replace(_step_count=np.int32(step_count))  # type: ignore

pgx/shogi.py

@@ -17,13 +17,9 @@
 import jax.numpy as jnp
 
 import pgx.core as core
-from pgx._src.shogi_utils import (
-    _from_sfen,
-    _to_sfen,
-)
 from pgx._src.struct import dataclass
 from pgx._src.types import Array, PRNGKey
-from pgx._src.games.shogi import MAX_TERMINATION_STEPS, GameState, Game, _observe, _flip
+from pgx._src.games.shogi import MAX_TERMINATION_STEPS, GameState, Game, _observe
 
 
 TRUE = jnp.bool_(True)
@@ -55,25 +51,6 @@ class State(core.State):
     def env_id(self) -> core.EnvId:
         return "shogi"
 
-    @staticmethod
-    def _from_board(turn, piece_board: Array, hand: Array):
-        """Mainly for debugging purpose.
-        terminated, reward, and current_player are not changed"""
-        state = State(_x=GameState(turn=turn, board=piece_board, hand=hand))  # type: ignore
-        # fmt: off
-        state = jax.lax.cond(turn % 2 == 1, lambda: state.replace(_x=_flip(state._x)), lambda: state)  # type: ignore
-        # fmt: on
-        return state.replace(legal_action_mask=Game().legal_action_mask(state._x))  # type: ignore
-
-    @staticmethod
-    def _from_sfen(sfen):
-        turn, pb, hand, step_count = _from_sfen(sfen)
-        return jax.jit(State._from_board)(turn, pb, hand).replace(_step_count=jnp.int32(step_count))  # type: ignore
-
-    def _to_sfen(self):
-        state = self if self._x.turn % 2 == 0 else self.replace(_x=_flip(self._x))  # type: ignore
-        return _to_sfen(state)
-
 
 class Shogi(core.Env):