Mercurial > hg
view mercurial/parser.py @ 20858:bc56ec9e64df stable
hg: introduce "wirepeersetupfuncs" to setup wire peer by extensions (issue4109)
Since changeset 6f72e7d28b35, "reposetup()" of each extensions is
invoked only on repositories enabling corresponded extensions.
This causes that largefiles specific interactions between the
repository enabling largefiles locally and remote (wire) peer fail,
because there is no way to know whether largefiles is enabled on the
remote repository behind the wire peer, and largefiles specific
"wireproto functions" are not given to any wire peers.
To avoid this problem, largefiles should be enabled in wider scope
than each repositories (e.g. user-wide "${HOME}/.hgrc").
This patch introduces "wirepeersetupfuncs" to setup wire peer by
extensions already enabled. Functions registered into
"wirepeersetupfuncs" are invoked for all wire peers.
This patch uses plain list instead of "util.hooks" for
"wirepeersetupfuncs", because the former allows to control order of
function invocation by order of extension enabling: it may be useful
for workaround of problems with combination of enabled extensions
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Sat, 29 Mar 2014 01:20:07 +0900 |
parents | 8ac8db8dc346 |
children | 7c4778bc29f0 |
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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 pairs # elements is a mapping of types to binding strength, prefix and infix actions # an action is a tree node name, a tree label, and an optional match # __call__(program) parses program into a labeled tree import error from i18n import _ class parser(object): def __init__(self, tokenizer, elements, methods=None): self._tokenizer = tokenizer self._elements = elements self._methods = methods self.current = None def _advance(self): 'advance the tokenizer' t = self.current try: self.current = self._iter.next() except StopIteration: pass return t def _match(self, m, pos): '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 _parse(self, bind=0): token, value, pos = self._advance() # handle prefix rules on current token prefix = self._elements[token][1] if not prefix: raise error.ParseError(_("not a prefix: %s") % token, pos) if len(prefix) == 1: expr = (prefix[0], value) else: if len(prefix) > 2 and prefix[2] == self.current[0]: self._match(prefix[2], pos) expr = (prefix[0], None) else: expr = (prefix[0], self._parse(prefix[1])) if len(prefix) > 2: self._match(prefix[2], pos) # gather tokens until we meet a lower binding strength while bind < self._elements[self.current[0]][0]: token, value, pos = self._advance() e = self._elements[token] # check for suffix - next token isn't a valid prefix if len(e) == 4 and not self._elements[self.current[0]][1]: suffix = e[3] expr = (suffix[0], expr) else: # handle infix rules if len(e) < 3 or not e[2]: raise error.ParseError(_("not an infix: %s") % token, pos) infix = e[2] if len(infix) == 3 and infix[2] == self.current[0]: self._match(infix[2], pos) expr = (infix[0], expr, (None)) else: expr = (infix[0], expr, self._parse(infix[1])) if len(infix) == 3: self._match(infix[2], pos) return expr def parse(self, message): 'generate a parse tree from a message' self._iter = self._tokenizer(message) 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, message): 'parse a message into a parse tree and evaluate if methods given' t = self.parse(message) if self._methods: return self.eval(t) return t