Struct SchemaBuilder

pub struct SchemaBuilder {
    fields: Vec<FieldRef>,
    metadata: HashMap<String, String>,
}

A builder to facilitate building a Schema from iteratively from FieldRef

Fields

fields: Vec<FieldRef>

metadata: HashMap<String, String>

Implementations

impl SchemaBuilder

pub fn new() -> Self

Creates a new empty SchemaBuilder

pub fn with_capacity(capacity: usize) -> Self

Creates a new empty SchemaBuilder with space for capacity fields

pub fn push(&mut self, field: impl Into<FieldRef>)

Appends a FieldRef to this SchemaBuilder without checking for collision

pub fn remove(&mut self, idx: usize) -> FieldRef

Removes and returns the FieldRef as index idx

Panics

Panics if index out of bounds

pub fn field(&mut self, idx: usize) -> &FieldRef

Returns an immutable reference to the FieldRef at index idx

Panics

Panics if index out of bounds

pub fn field_mut(&mut self, idx: usize) -> &mut FieldRef

Returns a mutable reference to the FieldRef at index idx

Panics

Panics if index out of bounds

pub fn metadata(&mut self) -> &HashMap<String, String>

Returns an immutable reference to the Map of custom metadata key-value pairs.

pub fn metadata_mut(&mut self) -> &mut HashMap<String, String>

Returns a mutable reference to the Map of custom metadata key-value pairs.

pub fn reverse(&mut self)

Reverse the fileds

pub fn try_merge(&mut self, field: &FieldRef) -> Result<(), ArrowError>

Appends a FieldRef to this SchemaBuilder checking for collision

If an existing field exists with the same name, calls Field::try_merge

pub fn finish(self) -> Schema

Consume this SchemaBuilder yielding the final Schema

Trait Implementations

impl Debug for SchemaBuilder

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

Formats the value using the given formatter.

impl Default for SchemaBuilder

fn default() -> SchemaBuilder

Returns the “default value” for a type.

impl Extend<Arc<Field>> for SchemaBuilder

fn extend<T: IntoIterator<Item = FieldRef>>(&mut self, iter: T)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl Extend<Field> for SchemaBuilder

fn extend<T: IntoIterator<Item = Field>>(&mut self, iter: T)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl From<&Fields> for SchemaBuilder

fn from(value: &Fields) -> Self

Converts to this type from the input type.

impl From<&Schema> for SchemaBuilder

fn from(value: &Schema) -> Self

Converts to this type from the input type.

impl From<Fields> for SchemaBuilder

fn from(value: Fields) -> Self

Converts to this type from the input type.

impl From<Schema> for SchemaBuilder

fn from(value: Schema) -> Self

Converts to this type from the input type.