Re: [boost] [Boost Review] Property Tree Library

From: Matias Capeletto (matias.capeletto_at_[hidden])
Date: 2006-04-24 13:47:34

On 4/24/06, Jeff Flinn <TriumphSprint2000_at_[hidden]> wrote:
> Thorsten Ottosen wrote:
> > Matias Capeletto wrote:
> >
> >> If we get the path into ptree we can overload other operator to
> >> support this type of path (we can not overload operator[]... because
> >> of precedence
> >> issues :( someone nows a way we can still use it?, the sintaxis will
> >> be very nice. As i see it, the only the choosen operator must have
> >> the same priority, see the examples, so we have only have * and % ).
> >>
> >> Something like this may work...
> >>
> >> ptree data;
> >> ptree::path p;
> >>
> >> data.put( p / "debug" / "info" / "testfail" , "somefile.hpp" );
> >> data.put( p / "debug" / "info" / "testfail" , "otherfile.hpp" );
> >> data.put( p / "debug" / "info" / "testfail" , "wer.hpp" );
> >>
> >> data.set( p / "debug" / "info" / "testfail" %2 , "file.hpp" ); // we
> >> use set!
> >
> > some simple function would allow you to write
> >
> > data.set( p / "debug" / "info" / "testfail" / at(2) , "file.hpp" );

Yes, it is possible, i still like the % more, i want that the
difference from indexing(%) and 'getNextChild' (/) can be read
directly from the code.

> > or we might say
> >
> > data.set( (p / "debug" / "info" / "testfail")[2] , "file.hpp" );

This have the drawback that we can not index internal nodes and
continue with a path...
That is the reason IMO the two operators must have the same precedence
level. And it is just beatifull to see that there are two operators (%
and *) that fullfill this requierement for the operator/. I think that
something like this

data.get( p / "log"%4 / "info" / "time" )

is very self descriptive. If there are less than 5 childs with the tag
"log" this will generate the result you choose when pick the dessired
get function (throw,optional,default)

> > or perhaps
> >
> > data.set( p / "debug" / "info" / "testfail[2]" , "file.hpp" );

This is ok... but if we give the option of using "log.info.time" or p
/ "log" / "info" / "time"
then we must consistenly give an option for indexing too.. and in the
case whe choose operator% or * i think it will be more clear if we use
the following notation...
"log%3.info.time" ( now that i see it in the screen "log[3].info.time"
is somewhat more nice to the view, what do you think?)