Enum StructMode

pub enum StructMode {
    ObjectOnly,
    ListOnly,
}

Specifies what is considered valid JSON when reading or writing RecordBatches or StructArrays.

This enum controls which form(s) the Reader will accept and which form the Writer will produce. For example, if the RecordBatch Schema is [("a", Int32), ("r", Struct([("b", Boolean), ("c", Utf8)]))] then a Reader with StructMode::ObjectOnly would read rows of the form {"a": 1, "r": {"b": true, "c": "cat"}} while with [‘StructMode::ListOnly’] would read rows of the form [1, [true, "cat"]]. A Writer would produce rows formatted similarly.

The list encoding is more compact if the schema is known, and is used by tools such as Presto and Trino.

When reading objects, the order of the key does not matter. When reading lists, the entries must be the same number and in the same order as the struct fields. Map columns are not affected by this option.

Variants

ObjectOnly

Encode/decode structs as objects (e.g., {“a”: 1, “b”: “c”})

ListOnly

Encode/decode structs as lists (e.g., [1, “c”])

Trait Implementations

impl Clone for StructMode

fn clone(&self) -> StructMode

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StructMode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for StructMode

fn default() -> StructMode

Returns the “default value” for a type.

impl PartialEq for StructMode

fn eq(&self, other: &StructMode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for StructMode

impl Eq for StructMode

impl StructuralPartialEq for StructMode