Mercurial > hg
view mercurial/registrar.py @ 27584:fc7c8cac6a4b
revset: use decorator to register a function as revset predicate
Using decorator can localize changes for adding (or removing) a revset
predicate function in source code.
It is also useful to pick predicates up for specific purpose. For
example, subsequent patch marks predicates as "safe" by decorator.
This patch defines 'parsefuncdecl()' in 'funcregistrar' class, because
this implementation can be uesd by other decorator class for fileset
predicate and template function.
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Tue, 29 Dec 2015 23:58:30 +0900 |
parents | 37d50250b696 |
children | 60bf90eb8bf8 |
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# registrar.py - utilities to register function for specific purpose # # Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import from . import ( util, ) class funcregistrar(object): """Base of decorator to register a fuction for specific purpose The least derived class can be defined by overriding 'table' and 'formatdoc', for example:: symbols = {} class keyword(funcregistrar): table = symbols formatdoc = ":%s: %s" @keyword('bar') def barfunc(*args, **kwargs): '''Explanation of bar keyword .... ''' pass In this case: - 'barfunc' is registered as 'bar' in 'symbols' - online help uses ":bar: Explanation of bar keyword" """ def __init__(self, decl): """'decl' is a name or more descriptive string of a function Specification of 'decl' depends on registration purpose. """ self.decl = decl table = None def __call__(self, func): """Execute actual registration for specified function """ name = self.getname() if func.__doc__ and not util.safehasattr(func, '_origdoc'): doc = func.__doc__.strip() func._origdoc = doc if callable(self.formatdoc): func.__doc__ = self.formatdoc(doc) else: # convenient shortcut for simple format func.__doc__ = self.formatdoc % (self.decl, doc) self.table[name] = func self.extraaction(name, func) return func def getname(self): """Return the name of the registered function from self.decl Derived class should override this, if it allows more descriptive 'decl' string than just a name. """ return self.decl def parsefuncdecl(self): """Parse function declaration and return the name of function in it """ i = self.decl.find('(') if i > 0: return self.decl[:i] else: return self.decl def formatdoc(self, doc): """Return formatted document of the registered function for help 'doc' is '__doc__.strip()' of the registered function. If this is overridden by non-callable object in derived class, such value is treated as "format string" and used to format document by 'self.formatdoc % (self.decl, doc)' for convenience. """ raise NotImplementedError() def extraaction(self, name, func): """Execute exra action for registered function, if needed """ pass