Re: parsing a stream

On Wed, Jul 04, 2018 at 08:30:11PM +0200, Seth wrote:
> On 04-07-18 15:59, Patrick Welche wrote:
> > Rather than read a huge document, and then parse it, is there a way of
> > reading chunks and pushing them through the parser, 
> Yes.

Great - any clue on how?

> > even though no one chunk on its own will be valid?
> 
> I'm not sure what you mean here.
> 
> Perhaps you can supply an example.

Simply, this works:

========================================================================
#include <iostream>
#include <string>

#include <boost/spirit/home/x3.hpp>

namespace x3 = boost::spirit::x3;

int main()
{
        std::string in("1 a 1.2 b");
        std::string::const_iterator iter = in.begin(), end = in.end();
        bool ok = x3::phrase_parse(
                iter, end,
                x3::int_ >> x3::char_ >> x3::double_ >> x3::char_,
                x3::ascii::space
        );

        if (!ok)
                std::cout << "Parsing failed\n";
        else if (iter != end)
                std::cout << "Bit left over at the end: "
                          << std::string(iter, end) << std::endl;
        else
                std::cout << "Success!\n";

        return 0;
}
========================================================================

but if I say, "iter, iter+3" then parsing will fail, and I can't carry
on with iter (now pointing to iter+3), end, i.e., try to split the tiny
string into 2 and do 2 batches.


Cheers,

Patrick

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