2011/3/10 Junio C Hamano <gitster@xxxxxxxxx>: > Let's step back a bit. > > We chose to use ":/<regexp>" as one new form of extended SHA-1 expression > to name an object for two reasons: (1) no normal <ref> can have a colon in > it, because of check-ref-format restriction; (2) ":" is an unlikely letter > to appear at the beginning of a pathname, and people with such a path can > work around by saying "./:frotz" or "\:xyzzy". > > There is a disambiguation logic to check a list of arguments that lacks an > explicit "--" separator to make sure that each element early on the list > can only be interpreted as an object name but not as a pathname that > exists on the filesystem, and all the remaining elements are pathnames > that exist on the filesystem. > > If we introduce an extended syntax for pathspec and make the prefix magic > character ":", and if we choose to use ":/" as one kind of magic, I was a > bit worried that this may affect the disambiguation. ÂThe users must use > an explicit "--" when feeding a pathspec with the magic so that the parser > knows which kind of magic (either object name magic or pathspec magic) > they are talking about. Or.. we can consider this ':' a special form of wildcard and interpret the same way: - first try exact match. If it matches, the leading ':' is interpreted literally as part of file name. - magic. > I however realized that it is not an issue at all, because the users > already need to disambiguate with "--" when using wildcards in their > pathspecs (e.g. "git log 'Makefil*'" will give you an ambiguity error). > Admittedly, wildcard pathspecs are lessor kind of magic, but they are > magic nevertheless. Yes, ':' is on the same side with wildcard pathspecs. > So my tentative conclusion is that there is no problem using the same ":" > as the magic introducer for pathspecs, just like we do for object names. > > Â Â Â ÂSide note: please point out flaws in the above train of thought > Â Â Â Âthat would make the end result non-workable. Huh? I failed. > I am not very happy with ":!" as negative from syntactical point of view, > because traditionally "!" is a tad cumbersome to quote in shells with > history support (e.g. "csh"), but unfortunately I don't think of any good > alternative that is easy to type. ÂPathspecs are globs by nature, and "!" > is a good choice of nagation indicator for that reason (think "[!aeiou]" > not "[^aeiou]" the latter of which is a regexp and not glob), though. We don't need to stick to ':!'. I just needed something to start coding. Other candidates can be '^' or '-' or '~'. '^' looks best in my opinion. -- Duy -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html