Struct DataTable 

pub struct DataTable { /* private fields */ }

Type-preserving columnar data backed by Arrow RecordBatch.

Provides row-oriented accessors for renderer compatibility while maintaining full Arrow type fidelity (timestamps, dates, decimals, etc.) for the transform pipeline.

Implementations

impl DataTable

pub fn from_record_batch(batch: RecordBatch) -> Self

Wrap an existing Arrow RecordBatch.

pub fn from_rows(rows: &[Row]) -> Result<Self, ChartError>

Convert JSON rows (from inline YAML data) into a DataTable. Type inference: Numbers → Float64, Booleans → Boolean, Strings → Utf8.

pub fn from_ipc_bytes(bytes: &[u8]) -> Result<Self, ChartError>

Deserialize from Arrow IPC bytes.

pub fn to_ipc_bytes(&self) -> Result<Vec<u8>, ChartError>

Serialize to Arrow IPC bytes.

pub fn num_rows(&self) -> usize

Number of rows.

pub fn num_columns(&self) -> usize

Number of columns.

pub fn is_empty(&self) -> bool

Whether the table has no rows.

pub fn record_batch(&self) -> &RecordBatch

Get the underlying RecordBatch.

pub fn schema(&self) -> Arc<Schema>

Get the Arrow schema.

pub fn get_f64(&self, row: usize, field: &str) -> Option<f64>

Extract an f64 value from a specific row and field. Handles all numeric Arrow types, Date32 (days since epoch), and Timestamps (epoch millis).

pub fn get_string(&self, row: usize, field: &str) -> Option<String>

Extract a string value from a specific row and field. Formats temporal types as ISO strings, numbers as decimal strings.

pub fn unique_values(&self, field: &str) -> Vec<String>

Get unique string values for a field, preserving first-appearance order.

pub fn all_values(&self, field: &str) -> Vec<String>

Get all string values for a field, preserving row order (including duplicates).

pub fn extent(&self, field: &str) -> Option<(f64, f64)>

Compute the extent (min, max) of a numeric field.

pub fn sum(&self, field: &str) -> f64

Sum a numeric field across all rows.

pub fn group_by(&self, field: &str) -> HashMap<String, DataTable>

Group rows by a field value, returning a map of group key → DataTable.

pub fn has_field(&self, field: &str) -> bool

Check if a field exists in the schema.

pub fn field_names(&self) -> Vec<String>

Get all field names.

pub fn to_rows(&self) -> Vec<Row>

Convert the Arrow RecordBatch back to JSON rows. Used for the built-in sync transform fallback path which operates on Vec<Row>.

Trait Implementations

impl Clone for DataTable

fn clone(&self) -> DataTable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DataTable

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

Formats the value using the given formatter.