generator.h

#ifndef __generator_h__
#define __generator_h__

// generator/continuation for C++
// author: Andrew Fedoniouk @ terrainformatica.com
// idea borrowed from: "coroutines in C" Simon Tatham,
//   http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html

struct _generator
{
    int _line;
    _generator() : _line(0) {}
};

#define $generator(NAME) struct NAME : public _generator

#define $emit(T) bool operator()(T& _rv) { \
                     switch(_line) { case 0:;

#define $stop  } _line = 0; return false; }

#define $yield(V) \
        do { \
            _line = __LINE__; \
            _rv = (V); return true; case __LINE__:; \
        } while (0)

// support for separate header/source pair
// author: smilekzs (http://github.com/smilekzs)

#define $emit_decl(T) bool operator()(T& _rv)
#define $emit_impl(NAME, T) bool NAME::operator()(T& _rv) { \
                                switch(_line) { case 0:;

#endif