Iterators are a mechanism used for producing sequences of values.
They are used to support for loops and ... argument unpacking syntax.
An iterator in Sphinx is anything that supports the __next metamethod.
An iterable is one of the following:
- A callable that when invoked with no arguments returns an iterator.
- An object that has the
__itermetamethod which returns am iterator. - A plain iterator is also an iterable.
__next takes no arguments and returns a tuple (next, ...) or nil.
invariant is a value that is passed to each invocation of iterfunc
i0 is a value that is passed to iterfunc as the initial value of i
Iterators can be used in a for loop like so:
for item in create_iter() do
echo item
end