Re: [RFC] Git config file reader in Perl (WIP)

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Jan 17, 2007, 10:44 UTC
Message-ID: <Pine.LNX.4.63.0701171138371.22628@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <200701171048.03686.jnareb@gmail.com>

Hi,

On Wed, 17 Jan 2007, Jakub Narebski wrote:

Show 18 quoted lines

> Johannes Schindelin wrote:
> > 
> > On Wed, 17 Jan 2007, Jakub Narebski wrote:
> > 
> >> Dnia wtorek 16. stycznia 2007 23:56, Johannes Schindelin napisa?:
> 
> >>> So, how about a "git repo-config --dump" which outputs a stream of NUL 
> >>> separated keys and values? This should be really easy to "parse", and 
> >>> there are no ambiguities: No key or value can contain a NUL.
> >> 
> >> Good idea, although "\n" would work as well as NUL.
> > 
> > No it would not:
> > 
> > 	[someSection]
> > 		thisKey = has\na\nvalue\with\nseveral\nnewlines
> 
> $ fatal: bad config file line <nn> in <config>

Yeah, sorry. But you got the point.

Show 8 quoted lines

> The same with quoted:
> 
>  	[someSection]
>  		qthisKey = "has\na\nvalue\with\nseveral\nnewlines"
> 
> There is no escaping besides escaping " and escape character
> i.e. escaping \ in git config. Se "\n" would work as well as NUL.
> (It is said explicitely that subsection names cannot contain "\n").

So you want "git-repo-config --dump" to output something which has to be scanned for escaping sequences?

If you call

	$ git repo-config -l

you will _no longer_ see "\n"s, but rather newlines.

I don't know why you insist on newlines, when a NUL makes perfect sense: Take everything until the next NUL. This is the key. Then take everything until the next NUL. This is the value. Repeat until EOF.

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> >> The only problem is with "key without value" case, i.e. something like
> >> 
> >>   [section]
> >>   	noval
> >> 
> >> which shows as
> >> 
> >>   section.noval
> > 
> > but is equivalent to
> > 
> > 	[section]
> > 		noval = true
> > 
> > Since it is by definition a boolean value.
> 
> But only for "git repo-config --bool --get section.noval" output.
> Semantically equivalent to "true".
> 
> But without --bool it returns like it was "".

Yes, it returns "", but this is _wrong_. A single "[section] noval" _only_ makes sense as a boolean. The information lies in its _presence_, which is as good as saying "true".

Ciao, Dscho