Added the core board loading functionality.

Author: eriq-augustine

pacai/boards/medium-classic.txt

@@ -1,3 +1,7 @@
+{
+    "class": "pacai.pacman.board.Board"
+}
+---
 %%%%%%%%%%%%%%%%%%%%
 %o...%........%....%
 %.%%.%.%%%%%%.%.%%.%

pacai/core/board.py

@@ -10,7 +10,18 @@
 
 SEPARATOR_PATTERN: re.Pattern = re.compile(r'^\s*-{3,}\s*$')
 
-DEFAULT_BOARD_CLASS = 'pacai.core.board.Board'
+DEFAULT_BOARD_CLASS: str = 'pacai.core.board.Board'
+
+DEFAULT_MARKER_EMPTY: str = ' '
+DEFAULT_MARKER_WALL: str = '%'
+
+class Marker(str):
+    """
+    A marker represents something that can appear on a board.
+    These are similar to a game piece of token in a traditional board game (like the top hat or dog in Monolopy).
+    """
+
+    pass
 
 class Board:
     """
@@ -26,9 +37,73 @@ class Board:
     The specific board class (usually specified by the board options) should know how to interpret the text-based board.
     """
 
-    def __init__(self, marker_wall = '%', **kwargs) -> None:
-        # TEST
-        pass
+    def __init__(self,
+            board_text: str,
+            marker_empty: str = DEFAULT_MARKER_EMPTY,
+            marker_wall: str = DEFAULT_MARKER_WALL,
+            extra_markers: list[str] = [],
+            strip: bool = True,
+            **kwargs) -> None:
+        self._markers: dict[str, Marker] = {
+            marker_empty: Marker(marker_empty),
+            marker_wall: Marker(marker_wall),
+        }
+        """ Map the text for a marker to the actual marker. """
+
+        for marker in extra_markers:
+            self._markers[marker] = Marker(marker)
+
+        height, width, locations = self._process_text(board_text, strip = strip)
+
+        self.height: int = height
+        """ The height (number of rows, "y") of the board. """
+
+        self.width: int = width
+        """ The width (number of columns, "x") of the board. """
+
+        self._locations: list[Marker] = locations
+        """ The full content of the board as a single list. """
+
+    def _process_text(self, board_text: str, strip: bool = True) -> tuple[int, int, list[Marker]]:
+        """
+        Create a board from a string.
+        """
+
+        if (strip):
+            board_text = board_text.strip()
+
+        if (len(board_text) == 0):
+            raise ValueError('A board cannot be empty.')
+
+        lines = board_text.split("\n")
+
+        height: int = len(lines)
+        width: int = -1
+        locations: list[Marker] = []
+
+        for row in range(len(lines)):
+            line = lines[row]
+            if (strip):
+                line = line.strip()
+
+            if (width == -1):
+                width = len(line)
+
+            if (width != len(line)):
+                raise ValueError(f"Unexpected width ({len(line)}) for row at index {row}. Expected {width}.")
+
+            for col in range(len(line)):
+                marker = self._markers.get(line[col], None)
+                if (marker is None):
+                    raise ValueError(f"Unknown marker '{line[col]}' found at location ({row}, {col}).")
+
+                locations.append(marker)
+
+        if (width == 0):
+            raise ValueError("A board must have at least one column.")
+
+        return height, width, locations
+
 
 def load_path(path: str) -> Board:
     """ Load a board from a file. """
@@ -62,4 +137,4 @@ def load_string(text: str) -> Board:
         options = pacai.util.json.loads(options_text)
 
     board_class = options.get('class', DEFAULT_BOARD_CLASS)
-    return pacai.util.reflection.new_object(board_class, **options)
+    return pacai.util.reflection.new_object(board_class, board_text, **options)

pacai/core/test_board.py

@@ -13,15 +13,21 @@ def test_load_default_boards(self):
     def test_load_test_boards(self):
         # [(board, expected error substring), ...]
         test_cases = [
-            ('', None),
             (TEST_BOARD_NO_SEP, None),
             (TEST_BOARD_OPTIONS, None),
             (TEST_BOARD_SEP_EMPTY_OPTIONS, None),
-            (TEST_BOARD_EMPTY_BOARD, None),
-            (TEST_BOARD_FULL_EMPTY, None),
-            (TEST_BOARD_FULL_EMPTY_SEP, None),
+
+            ('', 'A board cannot be empty.'),
+            (TEST_BOARD_ERROR_EMPTY_BOARD, 'A board cannot be empty.'),
+            (TEST_BOARD_ERROR_FULL_EMPTY, 'A board cannot be empty.'),
+            (TEST_BOARD_ERROR_FULL_EMPTY_SEP, 'A board cannot be empty.'),
 
             (TEST_BOARD_ERROR_BAD_CLASS, "Cannot find class 'ZZZ' in module 'pacai.core.board'."),
+
+            (TEST_BOARD_ERROR_WIDTH_ZERO, 'A board must have at least one column.'),
+            (TEST_BOARD_ERROR_INCONSISTENT_WIDTH, 'Unexpected width'),
+
+            (TEST_BOARD_ERROR_UNKNOWN_MARKER, 'Unknown marker'),
         ]
 
         for i in range(len(test_cases)):
@@ -40,42 +46,60 @@ def test_load_test_boards(self):
                     self.fail(f"Did not get expected error: '{error_substring}'.")
 
 TEST_BOARD_NO_SEP = '''
-%%%%%
-%. P%
-%%%%%
+%%%
+% %
+%%%
 '''
 
 TEST_BOARD_OPTIONS = '''
 {"marker_wall": "#"}
 ---
-#####
-#. P#
-#####
+###
+# #
+###
 '''
 
 TEST_BOARD_SEP_EMPTY_OPTIONS = '''
 ---
-%%%%%
-%. P%
-%%%%%
+%%%
+% %
+%%%
 '''
 
-TEST_BOARD_EMPTY_BOARD = '''
+TEST_BOARD_ERROR_EMPTY_BOARD = '''
 {"marker_wall": "#"}
 ---
 '''
 
-TEST_BOARD_FULL_EMPTY = '''
+TEST_BOARD_ERROR_FULL_EMPTY = '''
 '''
 
-TEST_BOARD_FULL_EMPTY_SEP = '''
+TEST_BOARD_ERROR_FULL_EMPTY_SEP = '''
 ---
 '''
 
 TEST_BOARD_ERROR_BAD_CLASS = '''
 {"class": "pacai.core.board.ZZZ"}
 ---
+%%%
+% %
+%%%
+'''
+
+TEST_BOARD_ERROR_WIDTH_ZERO = '''
+{"strip": false}
+---
+
+'''
+
+TEST_BOARD_ERROR_INCONSISTENT_WIDTH = '''
+%%%
+% %%
 %%%%%
-%. P%
-%%%%%
+'''
+
+TEST_BOARD_ERROR_UNKNOWN_MARKER = '''
+%%%
+%?%
+%%%
 '''

pacai/pacman/board.py

@@ -0,0 +1,27 @@
+import pacai.core.board
+
+MARKER_PELLET: pacai.core.board.Marker = pacai.core.board.Marker('.')
+MARKER_CAPSULE: pacai.core.board.Marker = pacai.core.board.Marker('o')
+MARKER_GHOST: pacai.core.board.Marker = pacai.core.board.Marker('G')
+MARKER_PACMAN: pacai.core.board.Marker = pacai.core.board.Marker('P')
+
+class Board(pacai.core.board.Board):
+    """
+    A board for Pacman.
+
+    In addition to walls, Pacman boards also have:
+    pellets ('.'),
+    capsules ('o'),
+    ghosts ('G'),
+    and Pacman ('P').
+    """
+
+    def __init__(self, board_text: str, extra_markers: list[str] = [], **kwargs) -> None:
+        extra_markers += [
+            MARKER_PELLET,
+            MARKER_CAPSULE,
+            MARKER_GHOST,
+            MARKER_PACMAN,
+        ]
+
+        super().__init__(board_text, extra_markers = extra_markers, **kwargs)