Struct FieldStruct 

pub struct FieldStruct {
    pub id: ModelId,
    pub fields: Vec<Field>,
    pub columns: IndexMap<ColumnId, usize>,
    pub field_mask: PathFieldSet,
    pub sub_projection: Projection,
    pub default_returning: Expr,
    pub presence: Option<ColumnId>,
}

Maps an embedded struct field to its flattened column representation.

Embedded fields are stored by flattening their primitive fields into columns with names like {field}_{embedded_field}. This structure tracks the mapping for each field in the embedded struct.

Examples

use toasty_core::schema::mapping::FieldStruct;

let s: &FieldStruct = field.as_struct().unwrap();
println!("{} nested fields, {} columns", s.fields.len(), s.columns.len());

Fields

id: ModelId

The ModelId of the embedded struct model this mapping corresponds to.

fields: Vec<Field>

Per-field mappings for the embedded struct’s fields.

Indexed by field index within the embedded model.

columns: IndexMap<ColumnId, usize>

Flattened mapping from columns to lowering expression indices.

This map contains all columns impacted by this embedded field, paired with their corresponding lowering expression index in Model::model_to_table.

field_mask: PathFieldSet

Update coverage mask for this embedded field.

The union of the field_mask bits of every primitive nested within this embedded struct (recursively).

sub_projection: Projection

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

default_returning: Expr

Pre-computed default record expression for this embedded struct.

Record([..]) shape matching the struct’s fields, with deferred sub-fields (direct or further nested) pre-masked to Null. Spliced in by process_includes when a parent .include() activates a Deferred<EmbedStruct> field.

presence: Option<ColumnId>

The presence head column of a nullable embedded struct (Option<Embed>).

None for a non-nullable embed. Some(column) when the field is Option<Embed>: the head column whose null-ness is the option’s none-ness (NULL = None), like Option<scalar> and an embedded enum’s discriminant. Usually a dedicated nullable bool column (NULL = None, true = Some); for a single-column (newtype) embed it is the flattened leaf reused as the head. The encode lowering forces every flattened leaf column nullable and the decode wraps the struct record in a Match on this column, so a None value round-trips without colliding with a Some whose fields are all themselves None. The column’s own encode lowering (if dedicated) is tracked in columns.

Trait Implementations

impl Clone for FieldStruct

fn clone(&self) -> FieldStruct

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldStruct

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

Formats the value using the given formatter.