Struct Schema 

pub struct Schema {
    pub schema: Vec<DataType>,
    pub col_names: HashMap<String, usize>,
}

Represents a Schema of a data frame

Fields

schema: Vec<DataType>

The DataTypes of this Schema

col_names: HashMap<String, usize>

A reverse column name to column index map for all the named columns. Helps getting the index by column name faster.

Implementations

impl Schema

The implementation of the Schema interface, which manages data types and row/column names of local and distributed data frames.

pub fn new() -> Self

Constructs an empty Schema.

pub fn add_column( &mut self, data_type: DataType, col_name: Option<String>, ) -> Result<(), LiquidError>

Add a column with the given data_type, with an optional column name, to this Schema. Column names must be unique. If col_name is Some and the name already exists in this Schema, the column will not be added to this Schema and a LiquidError::NameAlreadyExists error will be returned.

pub fn col_type(&self, idx: usize) -> Result<&DataType, LiquidError>

Get the data type of the column at the given idx Returns a result that will Error if the idx is out of bounds.

pub fn col_idx(&self, col_name: &str) -> Option<usize>

Given a column name, returns its index

pub fn col_name(&self, col_idx: usize) -> Result<Option<&str>, LiquidError>

Given a column index, returns its name

pub fn width(&self) -> usize

The number of columns in this Schema.

Trait Implementations

impl Clone for Schema

fn clone(&self) -> Schema

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Schema

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

Formats the value using the given formatter.

impl DeepSizeOf for Schema

fn deep_size_of_children(&self, context: &mut Context) -> usize

Returns an estimation of the heap-managed storage of this object. This does not include the size of the object itself.

fn deep_size_of(&self) -> usize

Returns an estimation of a total size of memory owned by the object, including heap-managed storage.

fn recurse_deep_size_of(&self, context: &mut Context) -> usize

👎Deprecated since 0.1.1: use std::mem::size_of_val(val) + val.deep_size_of_children() instead

Deprecated: equivalent to std::mem::size_of_val(val) + val.deep_size_of_children()

impl Default for Schema

fn default() -> Schema

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Schema

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<&Vec<Column>> for Schema

fn from(columns: &Vec<Column>) -> Self

Create a Schema from a Vec<Column>

impl From<&str> for Schema

fn from(types: &str) -> Self

Create a Schema from a &str of types. A string that contains characters other that B, I, F, or S will panic. Initializes the Column names to be None.

Character	DataType
‘B’	Bool
‘I’	Int
‘F’	Float
‘S’	String

impl From<Vec<DataType>> for Schema

fn from(types: Vec<DataType>) -> Self

Create a Schema from a Vec<DataType>

impl PartialEq for Schema

fn eq(&self, other: &Schema) -> 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 Serialize for Schema

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Schema