Struct Field 

pub struct Field { /* private fields */ }

One named field: a type, whether it may be null and whether it must be present, its constraints, and optionally the source’s own name for the type, a description and metadata.

Implementations

impl Field

pub fn new(name: impl Into<String>, data_type: DataType) -> Self

A nullable, optional field.

pub fn nullable(self, nullable: bool) -> Self

Whether the field may be null (default true).

pub fn required(self, required: bool) -> Self

Whether a value must be present (default false): JSON Schema’s required, SQL’s NOT NULL, a non-nullable Arrow field.

pub fn with_native_type(self, native: impl Into<String>) -> Self

The source format’s own name for the type, kept as written (Int32, VARCHAR(20), string | null). A schema tree shows it in place of the model’s type.

pub fn with_description(self, description: impl Into<String>) -> Self

A description, as the source gives it.

pub fn with_type(self, data_type: DataType) -> Self

Replace the type.

pub fn with_constraint(self, constraint: Constraint) -> Self

Add a constraint.

pub fn with_metadata( self, key: impl Into<String>, value: impl Into<String>, ) -> Self

Add a metadata entry (Arrow’s field metadata).

pub fn with_kind(self, kind: FieldKind) -> Self

How the field relates to its parent (default FieldKind::Field).

pub fn with_reference(self, reference: impl Into<String>) -> Self

The named definition the type was found through (#/$defs/item).

pub fn with_unexpanded(self, unexpanded: Unexpanded) -> Self

Mark the type as named by a reference that is not drawn in place.

pub fn elided(self, elided: bool) -> Self

Mark the children as left out, at a depth limit.

pub fn name(&self) -> &str

The name.

pub fn data_type(&self) -> &DataType

The type.

pub fn data_type_mut(&mut self) -> &mut DataType

The type, to change in place.

pub fn is_nullable(&self) -> bool

Whether the field may be null.

pub fn is_required(&self) -> bool

Whether a value must be present.

pub fn native_type(&self) -> Option<&str>

The source’s own type name, if one was recorded.

pub fn type_label(&self) -> String

The type as a tree shows it: the native type, else the model’s.

pub fn description(&self) -> Option<&str>

The description, if any.

pub fn constraints(&self) -> &[Constraint]

The constraints, in the order the source gives them.

pub fn constraints_mut(&mut self) -> &mut Vec<Constraint>

The constraints, to change in place.

pub fn constraint(&self, key: &str) -> Option<&Constraint>

The first constraint with key (Constraint::key).

pub fn metadata(&self) -> &[(String, String)]

The metadata entries, in order.

pub fn enum_values(&self) -> Option<&[Literal]>

The listed values, when the field is an enum.

pub fn default_value(&self) -> Option<&Literal>

The default value, if any.

pub fn is_primary_key(&self) -> bool

Whether the field is (part of) the primary key.

pub fn is_unique(&self) -> bool

Whether the field’s values are unique on their own.

pub fn references(&self) -> Option<&ForeignKey>

What the field refers to, if it is a foreign key.

pub fn kind(&self) -> FieldKind

How the field relates to its parent.

pub fn reference(&self) -> Option<&str>

The named definition the type was found through.

pub fn unexpanded(&self) -> Option<&Unexpanded>

Why the type is not drawn in place, when it is not.

pub fn is_elided(&self) -> bool

Whether the children were left out at a depth limit.

pub fn children(&self) -> impl Iterator<Item = &Field>

The nested fields (DataType::children).

Trait Implementations

impl Clone for Field

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Field

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

Formats the value using the given formatter.

impl Eq for Field

impl FromIterator<Field> for Schema

fn from_iter<I: IntoIterator<Item = Field>>(iter: I) -> Self

Creates a value from an iterator.

impl Hash for Field

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Field

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Field