Mercurial > public > mercurial-scm > hg-stable
comparison mercurial/parser.py @ 28895:4bf9ed7a260e
parser: move functions that process alias expansion to rule-set class
They will be commonly used by revset and templater. It isn't easy to understand
how _expand() works, so I'll add comments by a follow-up patch.
The local variable 'alias' is renamed to 'a' to avoid shadowing the global
'alias' class.
| author | Yuya Nishihara <yuya@tcha.org> |
|---|---|
| date | Mon, 29 Feb 2016 22:15:44 +0900 |
| parents | ee11167fe1da |
| children | 4c76a032ec7e |
comparison
equal
deleted
inserted
replaced
| 28894:0f59674dc9ff | 28895:4bf9ed7a260e |
|---|---|
| 470 aliases = {} | 470 aliases = {} |
| 471 for decl, defn in items: | 471 for decl, defn in items: |
| 472 a = cls.build(decl, defn) | 472 a = cls.build(decl, defn) |
| 473 aliases[a.name] = a | 473 aliases[a.name] = a |
| 474 return aliases | 474 return aliases |
| 475 | |
| 476 @classmethod | |
| 477 def _getalias(cls, aliases, tree): | |
| 478 """If tree looks like an unexpanded alias, return it. Return None | |
| 479 otherwise. | |
| 480 """ | |
| 481 if not isinstance(tree, tuple): | |
| 482 return None | |
| 483 if tree[0] == cls._symbolnode: | |
| 484 name = tree[1] | |
| 485 a = aliases.get(name) | |
| 486 if a and a.args is None and a.tree == tree: | |
| 487 return a | |
| 488 if tree[0] == cls._funcnode and tree[1][0] == cls._symbolnode: | |
| 489 name = tree[1][1] | |
| 490 a = aliases.get(name) | |
| 491 if a and a.args is not None and a.tree == tree[:2]: | |
| 492 return a | |
| 493 return None | |
| 494 | |
| 495 @classmethod | |
| 496 def _expandargs(cls, tree, args): | |
| 497 """Replace _aliasarg instances with the substitution value of the | |
| 498 same name in args, recursively. | |
| 499 """ | |
| 500 if not isinstance(tree, tuple): | |
| 501 return tree | |
| 502 if tree[0] == '_aliasarg': | |
| 503 sym = tree[1] | |
| 504 return args[sym] | |
| 505 return tuple(cls._expandargs(t, args) for t in tree) | |
| 506 | |
| 507 @classmethod | |
| 508 def _expand(cls, aliases, tree, expanding, cache): | |
| 509 if not isinstance(tree, tuple): | |
| 510 return tree | |
| 511 a = cls._getalias(aliases, tree) | |
| 512 if a is not None: | |
| 513 if a.error: | |
| 514 raise error.Abort(a.error) | |
| 515 if a in expanding: | |
| 516 raise error.ParseError(_('infinite expansion of %(section)s ' | |
| 517 '"%(name)s" detected') | |
| 518 % {'section': cls._section, | |
| 519 'name': a.name}) | |
| 520 expanding.append(a) | |
| 521 if a.name not in cache: | |
| 522 cache[a.name] = cls._expand(aliases, a.replacement, expanding, | |
| 523 cache) | |
| 524 result = cache[a.name] | |
| 525 expanding.pop() | |
| 526 if a.args is not None: | |
| 527 l = cls._getlist(tree[2]) | |
| 528 if len(l) != len(a.args): | |
| 529 raise error.ParseError(_('invalid number of arguments: %d') | |
| 530 % len(l)) | |
| 531 l = [cls._expand(aliases, t, [], cache) for t in l] | |
| 532 result = cls._expandargs(result, dict(zip(a.args, l))) | |
| 533 else: | |
| 534 result = tuple(cls._expand(aliases, t, expanding, cache) | |
| 535 for t in tree) | |
| 536 return result | |
| 537 | |
| 538 @classmethod | |
| 539 def expand(cls, aliases, tree): | |
| 540 """Expand aliases in tree, recursively. | |
| 541 | |
| 542 'aliases' is a dictionary mapping user defined aliases to alias objects. | |
| 543 """ | |
| 544 return cls._expand(aliases, tree, [], {}) |