Struct polars_arrow::ffi::ArrowArrayStreamReader

pub struct ArrowArrayStreamReader<Iter: DerefMut<Target = ArrowArrayStream>> { /* private fields */ }

Implements an iterator of Array consumed from the C stream interface.

Implementations

impl<Iter: DerefMut<Target = ArrowArrayStream>> ArrowArrayStreamReader<Iter>

pub unsafe fn try_new(iter: Iter) -> PolarsResult<Self>

Returns a new ArrowArrayStreamReader

Error

Errors iff the ArrowArrayStream is out of specification, or was already released prior to calling this function.

Safety

This method is intrinsically unsafe since it assumes that the ArrowArrayStream contains a valid Arrow C stream interface. In particular:

• The ArrowArrayStream fulfills the invariants of the C stream interface
• The schema get_schema produces fulfills the C data interface

pub fn field(&self) -> &Field

Returns the field provided by the stream

pub unsafe fn next(&mut self) -> Option<PolarsResult<Box<dyn Array>>>

Advances this iterator by one array

Error

Errors iff:

• The C stream interface returns an error
• The C stream interface returns an invalid array (that we can identify, see Safety below)

Safety

Calling this iterator’s next assumes that the ArrowArrayStream produces arrow arrays that fulfill the C data interface