The Spirit Parser Library: Inline Parsing in C++

Listing 4: The sequence class

//  Copyright (c) 2001, Joel de Guzman and Dan Nuffer
//  Permission is granted to use this code without restriction as
//  long as this copyright notice appears in all source files.

template <typename A, typename B>
struct sequence
    : public binary<A, B>
    , public parser<sequence<A, B> >
{
    sequence(A const& a, B const& b)
    : binary<A, B>(a, b) {}

    template <typename IteratorT>
    match parse(IteratorT& first, IteratorT const& last) const
    {
        IteratorT s = first;
        match ma, mb;
        if ((ma = this->left().parse(s, last)) &&
            (mb = this->right().parse(s, last)))
        {
            first = s;
            return ma + mb;
        }
        return match();
    }
};