parser.py

   1 """BulletML parser.
   2
   3 http://www.asahi-net.or.jp/~cs8k-cyu/bulletml/index_e.html
   4 """
   5
   6 from __future__ import division
   7
   8 from xml.etree.ElementTree import ElementTree
   9
  10 try:
  11     from cStringIO import StringIO
  12 except ImportError:
  13     from StringIO import StringIO
  14
  15 from bulletml.errors import Error
  16 from bulletml.expr import NumberDef, INumberDef
  17
  18 class ParseError(Error):
  19     """Raised when an error occurs parsing the XML structure."""
  20     pass
  21
  22 def realtag(element):
  23     """Strip namespace poop off the front of a tag."""
  24     try:
  25         return element.tag.rsplit('}', 1)[1]
  26     except ValueError:
  27         return element.tag
  28
  29 class ParamList(object):
  30     """List of parameter definitions."""
  31
  32     def __init__(self, params=[]):
  33         self.params = list(params)
  34
  35     @classmethod
  36     def FromElement(cls, doc, element):
  37         """Construct using an ElementTree-style element."""
  38         return cls([NumberDef(subelem.text) for subelem in element
  39                     if realtag(subelem) == "param"])
  40
  41     def __call__(self, params, rank):
  42         return [param(params, rank) for param in self.params]
  43
  44     def __repr__(self):
  45         return "%s(%r)" % (type(self).__name__, self.params)
  46
  47 class Direction(object):
  48     """Raw direction value."""
  49
  50     VALID_TYPES = ["relative", "absolute", "aim", "sequence"]
  51
  52     def __init__(self, type, value):
  53         if type not in self.VALID_TYPES:
  54             raise ValueError("invalid type %r" % type)
  55         self.type = type
  56         self.value = value
  57
  58     @classmethod
  59     def FromElement(cls, doc, element, default="absolute"):
  60         """Construct using an ElementTree-style element."""
  61         return cls(element.get("type", default), NumberDef(element.text))
  62
  63     def __call__(self, params, rank):
  64         return (self.value(params, rank), self.type)
  65
  66     def __repr__(self):
  67         return "%s(%r, type=%r)" % (
  68             type(self).__name__, self.value, self.type)
  69
  70 class ChangeDirection(object):
  71     """Direction change over time."""
  72
  73     def __init__(self, term, direction):
  74         self.term = term
  75         self.direction = direction
  76
  77     @classmethod
  78     def FromElement(cls, doc, element):
  79         """Construct using an ElementTree-style element."""
  80         for subelem in element.getchildren():
  81             tag = realtag(subelem)
  82             if tag == "direction":
  83                 direction = Direction.FromElement(doc, subelem)
  84             elif tag == "term":
  85                 term = INumberDef(subelem.text)
  86         try:
  87             return cls(term, direction)
  88         except UnboundLocalError as exc:
  89             raise ParseError(str(exc))
  90
  91     def __call__(self, params, rank):
  92         return self.term(params, rank), self.direction(params, rank)
  93
  94     def __repr__(self):
  95         return "%s(term=%r, direction=%r)" % (
  96             type(self).__name__, self.term, self.direction)
  97
  98 class Speed(object):
  99     """Raw speed value."""
 100
 101     VALID_TYPES = ["relative", "absolute", "sequence"]
 102
 103     def __init__(self, type, value):
 104         if type not in self.VALID_TYPES:
 105             raise ValueError("invalid type %r" % type)
 106         self.type = type
 107         self.value = value
 108
 109     @classmethod
 110     def FromElement(cls, doc, element):
 111         """Construct using an ElementTree-style element."""
 112         return cls(element.get("type", "absolute"), NumberDef(element.text))
 113
 114     def __call__(self, params, rank):
 115         return (self.value(params, rank), self.type)
 116
 117     def __repr__(self):
 118         return "%s(%r, type=%r)" % (type(self).__name__, self.value, self.type)
 119
 120 class ChangeSpeed(object):
 121     """Speed change over time."""
 122
 123     def __init__(self, term, speed):
 124         self.term = term
 125         self.speed = speed
 126
 127     @classmethod
 128     def FromElement(cls, doc, element):
 129         """Construct using an ElementTree-style element."""
 130         for subelem in element.getchildren():
 131             tag = realtag(subelem)
 132             if tag == "speed":
 133                 speed = Speed.FromElement(doc, subelem)
 134             elif tag == "term":
 135                 term = INumberDef(subelem.text)
 136         try:
 137             return cls(term, speed)
 138         except UnboundLocalError as exc:
 139             raise ParseError(str(exc))
 140
 141     def __call__(self, params, rank):
 142         return self.term(params, rank), self.speed(params, rank)
 143
 144     def __repr__(self):
 145         return "%s(term=%r, speed=%r)" % (
 146             type(self).__name__, self.term, self.speed)
 147
 148 class Wait(object):
 149     """Wait for some frames."""
 150
 151     def __init__(self, frames):
 152         self.frames = frames
 153
 154     @classmethod
 155     def FromElement(cls, doc, element):
 156         """Construct using an ElementTree-style element."""
 157         return cls(INumberDef(element.text))
 158
 159     def __call__(self, params, rank):
 160         return self.frames(params, rank)
 161
 162     def __repr__(self):
 163         return "%s(%r)" % (type(self).__name__, self.frames)
 164
 165 class Vanish(object):
 166     """Make the owner disappear."""
 167
 168     def __init__(self):
 169         pass
 170
 171     @classmethod
 172     def FromElement(cls, doc, element):
 173         """Construct using an ElementTree-style element."""
 174         return cls()
 175
 176     def __repr__(self):
 177         return "%s()" % (type(self).__name__)
 178
 179 class Repeat(object):
 180     """Repeat an action definition."""
 181
 182     def __init__(self, times, action):
 183         self.times = times
 184         self.action = action
 185
 186     @classmethod
 187     def FromElement(cls, doc, element):
 188         """Construct using an ElementTree-style element."""
 189         for subelem in element.getchildren():
 190             tag = realtag(subelem)
 191             if tag == "times":
 192                 times = INumberDef(subelem.text)
 193             elif tag == "action":
 194                 action = ActionDef.FromElement(doc, subelem)
 195             elif tag == "actionRef":
 196                 action = ActionRef.FromElement(doc, subelem)
 197         try:
 198             return cls(times, action)
 199         except UnboundLocalError as exc:
 200             raise ParseError(str(exc))
 201
 202     def __call__(self, params, rank):
 203         return self.times(params, rank), self.action(params, rank)
 204
 205     def __repr__(self):
 206         return "%s(%r, %r)" % (type(self).__name__, self.times, self.action)
 207
 208 class Accel(object):
 209     """Accelerate over some time."""
 210
 211     horizontal = None
 212     vertical = None
 213
 214     def __init__(self, term, horizontal=None, vertical=None):
 215         self.term = term
 216         self.horizontal = horizontal
 217         self.vertical = vertical
 218
 219     @classmethod
 220     def FromElement(cls, doc, element):
 221         """Construct using an ElementTree-style element."""
 222         horizontal = None
 223         vertical = None
 224
 225         for subelem in element.getchildren():
 226             tag = realtag(subelem)
 227             if tag == "term":
 228                 term = INumberDef(subelem.text)
 229             elif tag == "horizontal":
 230                 horizontal = Speed.FromElement(doc, subelem)
 231             elif tag == "vertical":
 232                 vertical = Speed.FromElement(doc, subelem)
 233
 234         try:
 235             return cls(term, horizontal, vertical)
 236         except AttributeError:
 237             raise ParseError
 238
 239     def __call__(self, params, rank):
 240         frames = self.term(params, rank)
 241         horizontal = self.horizontal and self.horizontal(params, rank)
 242         vertical = self.vertical and self.vertical(params, rank)
 243         return frames, horizontal, vertical
 244
 245     def __repr__(self):
 246         return "%s(%r, horizontal=%r, vertical=%r)" % (
 247             type(self).__name__, self.term, self.horizontal, self.vertical)
 248
 249 class BulletDef(object):
 250     """Bullet definition."""
 251
 252     direction = None
 253     speed = None
 254
 255     def __init__(self, actions=[], direction=None, speed=None):
 256         self.direction = direction
 257         self.speed = speed
 258         self.actions = list(actions)
 259
 260     @classmethod
 261     def FromElement(cls, doc, element):
 262         """Construct using an ElementTree-style element."""
 263         actions = []
 264         speed = None
 265         direction = None
 266         for subelem in element.getchildren():
 267             tag = realtag(subelem)
 268             if tag == "direction":
 269                 direction = Direction.FromElement(doc, subelem)
 270             elif tag == "speed":
 271                 speed = Speed.FromElement(doc, subelem)
 272             elif tag == "action":
 273                 actions.append(ActionDef.FromElement(doc, subelem))
 274             elif tag == "actionRef":
 275                 actions.append(ActionRef.FromElement(doc, subelem))
 276         dfn = cls(actions, direction, speed)
 277         doc.bullets[element.get("label")] = dfn
 278         return dfn
 279
 280     def __call__(self, params, rank):
 281         actions = [action(params, rank) for action in self.actions]
 282         return (
 283             self.direction and self.direction(params, rank),
 284             self.speed and self.speed(params, rank),
 285             actions)
 286
 287     def __repr__(self):
 288         return "%s(direction=%r, speed=%r, actions=%r)" % (
 289             type(self).__name__, self.direction, self.speed, self.actions)
 290
 291 class BulletRef(object):
 292     """Create a bullet by name with parameters."""
 293
 294     def __init__(self, bullet, params=None):
 295         self.bullet = bullet
 296         self.params = params or ParamList()
 297
 298     @classmethod
 299     def FromElement(cls, doc, element):
 300         """Construct using an ElementTree-style element."""
 301         bullet = cls(element.get("label"), ParamList.FromElement(doc, element))
 302         doc._bullet_refs.append(bullet)
 303         return bullet
 304
 305     def __call__(self, params, rank):
 306         return self.bullet(self.params(params, rank), rank)
 307
 308     def __repr__(self):
 309         return "%s(params=%r, bullet=%r)" % (
 310             type(self).__name__, self.params, self.bullet)
 311
 312 class ActionDef(object):
 313     """Action definition."""
 314
 315     # This is self-referential, so it's filled in later.
 316     CONSTRUCTORS = dict()
 317
 318     def __init__(self, actions):
 319         self.actions = list(actions)
 320
 321     @classmethod
 322     def FromElement(cls, doc, element):
 323         """Construct using an ElementTree-style element."""
 324         actions = []
 325         for subelem in element.getchildren():
 326             tag = realtag(subelem)
 327             try:
 328                 ctr = cls.CONSTRUCTORS[tag]
 329             except KeyError:
 330                 continue
 331             else:
 332                 actions.append(ctr.FromElement(doc, subelem))
 333         dfn = cls(actions)
 334         doc.actions[element.get("label")] = dfn
 335         return dfn
 336
 337     def __call__(self, params, rank):
 338         return self.actions, params
 339
 340     def __repr__(self):
 341         return "%s(%r)" % (type(self).__name__, self.actions)
 342
 343 class ActionRef(object):
 344     """Run an action by name with parameters."""
 345
 346     def __init__(self, action, params=None):
 347         self.action = action
 348         self.params = params or ParamList()
 349
 350     @classmethod
 351     def FromElement(cls, doc, element):
 352         """Construct using an ElementTree-style element."""
 353         action = cls(element.get("label"), ParamList.FromElement(doc, element))
 354         doc._action_refs.append(action)
 355         return action
 356
 357     def __call__(self, params, rank):
 358         return self.action(self.params(params, rank), rank)
 359
 360     def __repr__(self):
 361         return "%s(params=%r, action=%r)" % (
 362             type(self).__name__, self.params, self.action)
 363
 364 class FireDef(object):
 365     """Fire definition (creates a bullet)."""
 366
 367     def __init__(self, bullet, direction=None, speed=None):
 368         self.bullet = bullet
 369         self.direction = direction
 370         self.speed = speed
 371
 372     @classmethod
 373     def FromElement(cls, doc, element):
 374         """Construct using an ElementTree-style element."""
 375         direction = None
 376         speed = None
 377
 378         for subelem in element.getchildren():
 379             tag = realtag(subelem)
 380             if tag == "direction":
 381                 direction = Direction.FromElement(doc, subelem, "aim")
 382             elif tag == "speed":
 383                 speed = Speed.FromElement(doc, subelem)
 384             elif tag == "bullet":
 385                 bullet = BulletDef.FromElement(doc, subelem)
 386             elif tag == "bulletRef":
 387                 bullet = BulletRef.FromElement(doc, subelem)
 388
 389         try:
 390             fire = cls(bullet, direction, speed)
 391         except UnboundLocalError as exc:
 392             raise ParseError(str(exc))
 393         else:
 394             doc.fires[element.get("label")] = fire
 395             return fire
 396
 397     def __call__(self, params, rank):
 398         direction, speed, actions = self.bullet(params, rank)
 399         if self.direction:
 400             direction = self.direction(params, rank)
 401         if self.speed:
 402             speed = self.speed(params, rank)
 403         return direction, speed, actions
 404
 405     def __repr__(self):
 406         return "%s(direction=%r, speed=%r, bullet=%r)" % (
 407             type(self).__name__, self.direction, self.speed, self.bullet)
 408
 409 class FireRef(object):
 410     """Fire a bullet by name with parameters."""
 411
 412     def __init__(self, fire, params=None):
 413         self.fire = fire
 414         self.params = params or ParamList()
 415
 416     @classmethod
 417     def FromElement(cls, doc, element):
 418         """Construct using an ElementTree-style element."""
 419         fired = cls(element.get("label"), ParamList.FromElement(doc, element))
 420         doc._fire_refs.append(fired)
 421         return fired
 422
 423     def __call__(self, params, rank):
 424         """Generate a Bullet from the FireDef and params."""
 425         return self.fire(self.params(params, rank), rank)
 426
 427     def __repr__(self):
 428         return "%s(params=%r, fire=%r)" % (
 429             type(self).__name__, self.params, self.fire)
 430
 431 class BulletML(object):
 432     """BulletML document.
 433
 434     A BulletML document is a collection of bullets, actions, and
 435     firings, as well as a base game type.
 436     """
 437
 438     CONSTRUCTORS = dict(
 439         bullet=BulletDef,
 440         action=ActionDef,
 441         fire=FireDef,
 442         )
 443
 444     def __init__(self, source):
 445         self.bullets = {}
 446         self.actions = {}
 447         self.fires = {}
 448
 449         self._bullet_refs = []
 450         self._action_refs = []
 451         self._fire_refs = []
 452
 453         if isinstance(source, (str, unicode)):
 454             source = StringIO(source)
 455
 456         tree = ElementTree()
 457         root = tree.parse(source)
 458
 459         self.type = root.get("type", "none")
 460
 461         for element in root.getchildren():
 462             tag = realtag(element)
 463             if tag in self.CONSTRUCTORS:
 464                 self.CONSTRUCTORS[tag].FromElement(self, element)
 465
 466         try:
 467             for ref in self._bullet_refs:
 468                 ref.bullet = self.bullets[ref.bullet]
 469             for ref in self._fire_refs:
 470                 ref.fire = self.fires[ref.fire]
 471             for ref in self._action_refs:
 472                 ref.action = self.actions[ref.action]
 473         except KeyError as exc:
 474             raise ParseError("unknown reference %s" % exc)
 475
 476         del(self._bullet_refs)
 477         del(self._action_refs)
 478         del(self._fire_refs)
 479
 480         self.bullets.pop(None, None)
 481         self.actions.pop(None, None)
 482         self.fires.pop(None, None)
 483
 484     @property
 485     def top(self):
 486         """Get a list of all top-level actions."""
 487         return [dfn for name, dfn in self.actions.iteritems()
 488                 if name and name.startswith("top")]
 489
 490     def __repr__(self):
 491         return "%s(type=%r, bullets=%r, actions=%r, fires=%r)" % (
 492             type(self).__name__, self.type, self.bullets, self.actions,
 493             self.fires)
 494
 495 ActionDef.CONSTRUCTORS = dict(
 496         repeat=Repeat,
 497         fire=FireDef,
 498         fireRef=FireRef,
 499         changeSpeed=ChangeSpeed,
 500         changeDirection=ChangeDirection,
 501         accel=Accel,
 502         wait=Wait,
 503         vanish=Vanish,
 504         action=ActionDef,
 505         actionRef=ActionRef)