snake: snake.py annotate

snake

annotate snake.py @ 134:8e75e931bfd2

example.snake: better rules for chasing enemy tail

author	Daniil Alexeyevsky <me.dendik@gmail.com>
date	Mon, 20 Dec 2010 17:01:39 +0300
parents	bc310be50e73
children	cd7658cb90eb

rev	line source
me@44	1 """Guts of snakes."""
me@44	2
me@34	3 import engine
me@34	4
me@34	5 def preprocess(line):
me@44	6 """Remove comments and junk spaces from line of snake definition file."""
me@34	7 if '//' in line:
me@34	8 line = line[:line.index('//')]
me@34	9 line = line.rstrip()
me@34	10 return line
martiran@30	11
me@109	12 class File(object):
me@109	13 """Wrapper around file that saves the current line number."""
me@109	14 def __init__(self, file):
me@109	15 self.file = file
me@109	16 self.name = file.name
me@109	17 self.line_no = 0
me@120	18 self.iterator = self.enumerate_lines()
me@109	19 def __iter__(self):
me@120	20 return self.iterator
me@120	21 def enumerate_lines(self):
me@109	22 for line_no, line in enumerate(self.file, self.line_no):
me@109	23 self.line_no = line_no
me@109	24 yield line
me@109	25
martiran@30	26 class Snake(object):
me@44	27 """Snakes.
me@44	28
me@44	29 Attributes:
me@44	30
me@44	31 - `cells` -- list of cells belonging to the snake The first of these cells
me@44	32 becomes head, the last one becomes tail, the rest ar body. If snake has
me@44	33 only one cell, it is tail.
me@44	34 - `color` -- color of snake
me@44	35 - `rules` -- a list of Rule objects
me@44	36 """
me@44	37
martiran@32	38 def __init__ (self, cells, color):
martiran@32	39 self.cells = cells
martiran@32	40 self.color = color
martiran@32	41 self.rules = []
me@34	42
me@34	43 def load (self, file):
me@44	44 """Load snake description from file.
me@44	45
me@44	46 See program design docs for file syntax.
me@44	47 """
me@109	48 file = File(file)
me@109	49 try:
me@109	50 self._load(file)
me@109	51 except Exception, e:
me@109	52 raise Exception("%s:%s: %s" % (file.name, file.line_no, e))
me@109	53
me@109	54 def _load (self, file):
me@109	55 """Actually do the loading."""
me@65	56 for line in file:
me@88	57 magic, self.name = preprocess(line).split(' ', 1)
me@65	58 break
me@34	59 assert magic == "snake", "This is not snake file"
me@65	60 for line in file:
me@65	61 line = preprocess(line)
me@34	62 if line == 'end':
me@34	63 break
me@34	64 assert line == '', "Rules must be separated by empty lines"
me@51	65 self.rules.append(Rule(self).load(file))
me@34	66
martiran@30	67 def fill (self):
me@44	68 """Mark every cell in `self.cells` as belonging to self."""
martiran@32	69 for cell in self.cells:
martiran@32	70 cell.snake = self
me@129	71 if self.cells == []:
me@129	72 return
martiran@111	73 for cell in self.cells:
martiran@111	74 cell.type = 'body'
Alex@75	75 self.cells[0].type = 'head'
Alex@75	76 self.cells[-1].type = 'tail'
me@34	77
martiran@30	78 class Rule(object):
me@44	79 """Rule defining possible behaviour of snake."""
me@34	80
me@34	81 codes = {
me@34	82 'h': 'head',
me@34	83 'b': 'body',
me@34	84 't': 'tail',
me@34	85 '#': 'wall',
me@34	86 ' ': 'any',
me@34	87 '-': 'empty',
me@34	88 }
me@34	89
martiran@32	90 def __init__ (self, snake):
martiran@32	91 self.snake = snake
me@80	92 self.direction = (0, -1)
me@34	93 self.pattern = {}
me@34	94
me@34	95 def load (self, file):
me@70	96 """Load rule definition from file.
me@70	97
me@70	98 Ignore any leading empty lines.
me@70	99 Return self.
me@70	100 """
me@34	101 y = 0
me@34	102 for line in file:
me@34	103 line = preprocess(line)
me@34	104 if y == 0 and line == '':
me@34	105 continue
me@41	106 assert len(line) == 8, "Rule lines must be exactly 7 chars long"
me@34	107 assert line[-1] == ';', "Rule lines must end with semicolon"
me@63	108 for x, char in enumerate(line[:7]):
me@34	109 self.parse_cell(x, y, char)
me@34	110 y += 1
me@68	111 if y == 7:
me@68	112 break
me@70	113 return self
me@34	114
me@34	115 def parse_cell(self, x, y, char):
me@44	116 """Parse definition of cell in rule file.
me@44	117
me@44	118 Cell is defined by one character.
me@44	119 """
me@73	120 is_my = char.islower()
me@73	121 char = char.lower()
me@73	122 assert char in self.codes, "Illegal symbol in rule: %s" % char
me@115	123 cell = engine.Cell(x, y)
me@115	124 cell.snake = self.snake
me@124	125 cell.snake_type = None
me@34	126 if char in 'htb':
me@73	127 if is_my:
me@51	128 cell.snake_type = 'my'
me@34	129 else:
me@51	130 cell.snake_type = 'enemy'
me@37	131 if char == 'h':
me@37	132 assert (x, y) == (3, 3), "Own head must in the center of rule"
me@37	133 if (x, y) == (3, 3):
me@37	134 assert char == 'h', "In the center of rule must be own head"
me@73	135 cell.type = self.codes[char]
me@34	136 self.pattern[x, y] = cell
me@34	137
martiran@32	138 def applies (self, field, x, y):
me@44	139 """True if the rule applies in the field at position (x,y)."""
me@115	140 wall = engine.Cell(-1, -1)
me@115	141 wall.type = 'void'
me@115	142
me@38	143 for px, fx in zip(range(7), range(x - 3, x + 4)):
me@38	144 for py, fy in zip(range(7), range(y - 3, y + 4)):
me@115	145 if field.get((fx, fy), wall) != self.pattern[px, py]:
me@115	146 return False
me@38	147 return True
me@34	148
me@104	149 def rotate (self, direction):
me@104	150 """Rotate rule pattern to head in `direction`."""
me@104	151 for i in range(4):
me@104	152 if self.direction == direction:
me@104	153 return
me@39	154 self.rotate_ccw()
me@104	155 raise AssertionError("Illegal direction: %s" % direction)
me@39	156
me@39	157 def rotate_ccw(self):
me@44	158 """Rotate rule pattern one time counterclockwise."""
me@39	159 pattern = {}
me@39	160 for x in range(7):
me@39	161 for y in range(7):
me@39	162 pattern[y, 6 - x] = self.pattern[x, y]
me@39	163 self.pattern = pattern
me@39	164 x, y = self.direction
me@39	165 self.direction = y, -x
me@34	166
me@34	167 # vim: set ts=4 sts=4 sw=4 et: