Mercurial > hg
view mercurial/parser.py @ 26390:0f0cda81e9b0
gitweb: provide links to branches, tags and bookmarks by name
This is adapted from cd842821db2c, that was added to paper for 3.5 release.
It adds another way to refer to branches, tags and bookmarks in urls: by name.
It's still possible to navigate to a specific changeset hash, but now you can
get more descriptive urls straight from /summary page, for example.
branchentry template (and so the whole branches table on /summary and
/branches) lost the column that had a plain changeset hash, because tags and
bookmarks don't have this column and also because there is already a way to
address branch by its changeset hash (changeset link just next to it). Maybe we
can instead bring this column with a plain changeset hash to tags and
bookmarks, but this, more terse, new look feels fine.
author | Anton Shestakov <av6@dwimlabs.net> |
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date | Sat, 26 Sep 2015 17:15:58 +0800 |
parents | 87c9c562c37a |
children | 639e0f1e8ffa |
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# parser.py - simple top-down operator precedence parser for mercurial # # Copyright 2010 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. # see http://effbot.org/zone/simple-top-down-parsing.htm and # http://eli.thegreenplace.net/2010/01/02/top-down-operator-precedence-parsing/ # for background # takes a tokenizer and elements # tokenizer is an iterator that returns (type, value, pos) tuples # elements is a mapping of types to binding strength, primary, prefix, infix # and suffix actions # an action is a tree node name, a tree label, and an optional match # __call__(program) parses program into a labeled tree from __future__ import absolute_import from .i18n import _ from . import error class parser(object): def __init__(self, elements, methods=None): self._elements = elements self._methods = methods self.current = None def _advance(self): 'advance the tokenizer' t = self.current self.current = next(self._iter, None) return t def _hasnewterm(self): 'True if next token may start new term' return any(self._elements[self.current[0]][1:3]) def _match(self, m): 'make sure the tokenizer matches an end condition' if self.current[0] != m: raise error.ParseError(_("unexpected token: %s") % self.current[0], self.current[2]) self._advance() def _parseoperand(self, bind, m=None): 'gather right-hand-side operand until an end condition or binding met' if m and self.current[0] == m: expr = None else: expr = self._parse(bind) if m: self._match(m) return expr def _parse(self, bind=0): token, value, pos = self._advance() # handle prefix rules on current token, take as primary if unambiguous primary, prefix = self._elements[token][1:3] if primary and not (prefix and self._hasnewterm()): expr = (primary, value) elif prefix: expr = (prefix[0], self._parseoperand(*prefix[1:])) else: raise error.ParseError(_("not a prefix: %s") % token, pos) # gather tokens until we meet a lower binding strength while bind < self._elements[self.current[0]][0]: token, value, pos = self._advance() # handle infix rules, take as suffix if unambiguous infix, suffix = self._elements[token][3:] if suffix and not (infix and self._hasnewterm()): expr = (suffix[0], expr) elif infix: expr = (infix[0], expr, self._parseoperand(*infix[1:])) else: raise error.ParseError(_("not an infix: %s") % token, pos) return expr def parse(self, tokeniter): 'generate a parse tree from tokens' self._iter = tokeniter self._advance() res = self._parse() token, value, pos = self.current return res, pos def eval(self, tree): 'recursively evaluate a parse tree using node methods' if not isinstance(tree, tuple): return tree return self._methods[tree[0]](*[self.eval(t) for t in tree[1:]]) def __call__(self, tokeniter): 'parse tokens into a parse tree and evaluate if methods given' t = self.parse(tokeniter) if self._methods: return self.eval(t) return t def buildargsdict(trees, funcname, keys, keyvaluenode, keynode): """Build dict from list containing positional and keyword arguments Invalid keywords or too many positional arguments are rejected, but missing arguments are just omitted. """ if len(trees) > len(keys): raise error.ParseError(_("%(func)s takes at most %(nargs)d arguments") % {'func': funcname, 'nargs': len(keys)}) args = {} # consume positional arguments for k, x in zip(keys, trees): if x[0] == keyvaluenode: break args[k] = x # remainder should be keyword arguments for x in trees[len(args):]: if x[0] != keyvaluenode or x[1][0] != keynode: raise error.ParseError(_("%(func)s got an invalid argument") % {'func': funcname}) k = x[1][1] if k not in keys: raise error.ParseError(_("%(func)s got an unexpected keyword " "argument '%(key)s'") % {'func': funcname, 'key': k}) if k in args: raise error.ParseError(_("%(func)s got multiple values for keyword " "argument '%(key)s'") % {'func': funcname, 'key': k}) args[k] = x[2] return args def unescapestr(s): try: return s.decode("string_escape") except ValueError as e: # mangle Python's exception into our format raise error.ParseError(str(e).lower()) def _prettyformat(tree, leafnodes, level, lines): if not isinstance(tree, tuple) or tree[0] in leafnodes: lines.append((level, str(tree))) else: lines.append((level, '(%s' % tree[0])) for s in tree[1:]: _prettyformat(s, leafnodes, level + 1, lines) lines[-1:] = [(lines[-1][0], lines[-1][1] + ')')] def prettyformat(tree, leafnodes): lines = [] _prettyformat(tree, leafnodes, 0, lines) output = '\n'.join((' ' * l + s) for l, s in lines) return output def simplifyinfixops(tree, targetnodes): """Flatten chained infix operations to reduce usage of Python stack >>> def f(tree): ... print prettyformat(simplifyinfixops(tree, ('or',)), ('symbol',)) >>> f(('or', ... ('or', ... ('symbol', '1'), ... ('symbol', '2')), ... ('symbol', '3'))) (or ('symbol', '1') ('symbol', '2') ('symbol', '3')) >>> f(('func', ... ('symbol', 'p1'), ... ('or', ... ('or', ... ('func', ... ('symbol', 'sort'), ... ('list', ... ('or', ... ('or', ... ('symbol', '1'), ... ('symbol', '2')), ... ('symbol', '3')), ... ('negate', ... ('symbol', 'rev')))), ... ('and', ... ('symbol', '4'), ... ('group', ... ('or', ... ('or', ... ('symbol', '5'), ... ('symbol', '6')), ... ('symbol', '7'))))), ... ('symbol', '8')))) (func ('symbol', 'p1') (or (func ('symbol', 'sort') (list (or ('symbol', '1') ('symbol', '2') ('symbol', '3')) (negate ('symbol', 'rev')))) (and ('symbol', '4') (group (or ('symbol', '5') ('symbol', '6') ('symbol', '7')))) ('symbol', '8'))) """ if not isinstance(tree, tuple): return tree op = tree[0] if op not in targetnodes: return (op,) + tuple(simplifyinfixops(x, targetnodes) for x in tree[1:]) # walk down left nodes taking each right node. no recursion to left nodes # because infix operators are left-associative, i.e. left tree is deep. # e.g. '1 + 2 + 3' -> (+ (+ 1 2) 3) -> (+ 1 2 3) simplified = [] x = tree while x[0] == op: l, r = x[1:] simplified.append(simplifyinfixops(r, targetnodes)) x = l simplified.append(simplifyinfixops(x, targetnodes)) simplified.append(op) return tuple(reversed(simplified))