From: Hartmut Kaiser (hartmut.kaiser_at_[hidden])
Date: 2008-01-15 08:27:28
> I'm posting an early version of a library for manipulating
> hierarchical data structures, for example the parse trees
> that are produced by Spirit2. The library enables traversals,
> and local modifications of complex data structures, without
> the need to implement large amounts of repetitive traversal
> code. The library is in a very early state, but has a pretty
> large introduction and quick start guide, which (hopefully)
> will help get people started with the library. Formal
> documentation is unfortunately non-existent at this point.
>
> The library is based on techniques from the Haskell
> community, links to relevant papers are provided in the documentation.
>
> The library is intended to play well with the rest of Boost,
> it already contains support for structures built with
> Boost.Optional and Boost.Variant, and Boost.Fusion, and will
> support other Boost libraries in future releases. The library
> makes heavy use of function objects, and is intended to work
> with Boost.Lambda, Phoenix, and other function object
> libraries in Boost.
I second the expressed opinion that this library is a very important piece
of work and I'm looking forward to having it available.
IIUC, the traversal library is designed to help traversing arbitrary data
structures and to apply local _value_ changes. My question is:
Is the used concept extensible in a way allowing for _structural_ changes of
the traversed data structure? This would make it usable for tree
transformations, which would be especially interesting if used with
Spirit.Qi (parsing) and Spirit.Karma (generation).
Regards Hartmut