Re: [Boost-users] [spirit] qi xml parser

Subject: Re: [Boost-users] [spirit] qi xml parser
From: Michael Powell (mwpowellhtx_at_[hidden])
Date: 2014-06-30 17:44:00

On Mon, Jun 30, 2014 at 3:14 PM, Michael Powell <mwpowellhtx_at_[hidden]> wrote:
> Hello,
>
> I am building out a general use xml parser including attributes,
> arbitrary number of elements, and so on.
>
> So far so good, makes sense parsing names and so forth. However, how
> do you handle element content? Which could either be a string, or zero
> or more other elements (basically of the same rule as the enclosing
> element rule).
>
> It would seem you need a terminus, the empty element tag. In such a
> way that populates the parent (initial) element, and its children (of
> the same element kind).
>
> I'll be adapting structs to capture the results. I am also using a
> couple of helpful references, for instance:
>
> http://www.w3.org/TR/xml11/
> http://stackoverflow.com/questions/9473843/boost-spirit-how-to-extend-xml-parsing

I'm not sure reading the Xml specification, and some boost tickets
from several years ago, the following couldn't represent content:

content %= *(chars_ - chars_("<&")) | *(comment | child_element);

Where comment is defined as expected. child_element is the potential
for recursion into the element grammar where content is defined.
Basically a member variable of the same type as the container struct
(element grammar).

> Also not sure quite how to capture the adapted parts at strategic rule
> opportunities.
>
> My domain model will look something like this, keeping it simple as possible:
>
> struct xattribute {
>     std::string name;
>     std::string value;
> };
>
> typedef std::vector<xattribute> xattribute_vector;
>
> struct xelement;
>
> typedef std::vector<xelement> xelement_vector;
>
> struct xelement {
>     std::string name;
>     std::string content;
>     xattribute_vector attributes;
>     xelement_vector children;
> };
>
> Thanks...
>
> Best regards,
>
> Michael Powell