iter.h File Reference

Table iteration. More...

#include <iterator>
#include "table.h"

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Classes
class	nngn::lua::detail::table_iter_base< CRTP, T >
	CRTP base for table iterators. More...
class	nngn::lua::detail::table_iter< T >
	lua_next-based table iterator. More...
class	nngn::lua::detail::table_seq_iter< T >
	ipairs-style table iterator. More...

Namespaces
namespace	nngn
namespace	nngn::lua
namespace	nngn::lua::detail

Functions
template<typename CRTP , typename T >
bool	nngn::lua::detail::operator== (const table_iter_base< CRTP, T > &lhs, const table_iter_base< CRTP, T > &rhs)
template<typename T >
auto	nngn::lua::ipairs (const T &table)
	Simple wrapper for a table value, returns ipairs-style iterators.

Detailed Description

Table iteration.

Basic input iterators are available for very simple table iteration. Since it uses the Lua stack, this is only suitable for simple range for loops which do not leave values on the stack at the end of each iteration (or other cases, if you know what you are doing). The objects on the stack are automatically managed by the iterators and should not be moved. Their scope is limited to the for loop (or similar construct), (stack) references held after it will dangle.

The stack positions above the key/value can be manipulated freely inside the loop body, including before the iterators are dereferenced. In particular, nested iteration is supported.

Example lua_next-based iteration:

const auto t = lua.create_table();
for(const auto &[k, v] : …) t[k] = v;
for(auto [k, v] : t) use(k, v);

Example ipairs-style iteration:

const auto t = lua.create_table();
for(const auto &[i, x] : …) t[i] = x;
for(auto [i, x] : ipairs(t)) use(i, x);

Nested example:

for(auto [i, x] : ipairs(t))
    for(auto [k, v] : nngn::lua::table_view{x})
        ret[static_cast<std::size_t>(i) - 1].emplace_back(k, v);