Enum Field 

pub enum Field {
    Primitive(FieldPrimitive),
    Struct(FieldStruct),
    Enum(FieldEnum),
    Relation(FieldRelation),
}

Maps a model field to its database storage representation.

Different field types have different storage strategies:

• Primitive fields map to a single column
• Struct fields flatten an embedded struct to multiple columns
• Enum fields map to a discriminant column plus per-variant data columns
• Relation fields (BelongsTo, HasMany, HasOne) don’t have direct column storage

Examples

use toasty_core::schema::mapping::Field;

match &field {
    Field::Primitive(p) => println!("column {:?}", p.column),
    Field::Struct(s) => println!("{} nested fields", s.fields.len()),
    Field::Enum(e) => println!("discriminant col {:?}", e.discriminant.column),
    Field::Relation(_) => println!("relation (no columns)"),
}

Variants

Primitive(FieldPrimitive)

A primitive field stored in a single column.

Struct(FieldStruct)

An embedded struct field flattened into multiple columns.

Enum(FieldEnum)

An embedded enum field stored as a discriminant column plus per-variant data columns.

Relation(FieldRelation)

A relation field that doesn’t map to columns in this table.

Implementations

impl Field

pub fn field_mask(&self) -> PathFieldSet

Returns the update coverage mask for this field.

Each primitive (leaf) field in the model is assigned a unique bit. The mask for a given mapping field is the set of those bits that correspond to the primitives it covers:

• Primitive → singleton set containing only its own bit
• Struct → union of all nested primitive bits (recursively)
• Enum → singleton set (the whole enum value changes atomically)
• Relation → singleton set (assigned a bit for uniform tracking)

Masks are used during update lowering to determine whether a partial update fully covers an embedded field or only touches some of its sub-fields. Intersecting changed_mask with a field’s field_mask yields the subset of that field’s primitives being updated; equality with the full field_mask means full coverage.

pub fn sub_projection(&self) -> &Projection

Returns the sub-projection from the root model field to this field within the embedded type hierarchy. Identity for root-level fields.

pub fn is_relation(&self) -> bool

Returns true if this is a Field::Relation.

pub fn as_primitive(&self) -> Option<&FieldPrimitive>

Returns the inner FieldPrimitive if this is a Primitive variant, or None otherwise.

pub fn as_primitive_mut(&mut self) -> Option<&mut FieldPrimitive>

Returns a mutable reference to the inner FieldPrimitive if this is a Primitive variant, or None otherwise.

pub fn as_struct(&self) -> Option<&FieldStruct>

Returns the inner FieldStruct if this is a Struct variant, or None otherwise.

pub fn as_enum(&self) -> Option<&FieldEnum>

Returns the inner FieldEnum if this is an Enum variant, or None otherwise.

pub fn columns(&self) -> impl Iterator<Item = (ColumnId, usize)> + '_

Returns an iterator over all (column, lowering) pairs impacted by this field.

For primitive fields, yields a single pair. For struct fields, yields all flattened columns. For enum fields, yields the discriminant column plus all variant data columns. For relation fields, yields nothing.

Trait Implementations

impl Clone for Field

fn clone(&self) -> Field

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.