Enum Instance 

pub enum Instance {
    WType(WInstance),
    Functor(FInstance),
    Graph(GInstance),
}

A unified instance wrapping all instance shapes.

This is the top-level instance type for generic code. Each variant preserves the optimized internal representation of its shape.

All three shapes are attributed C-sets:

• WType: C = tree category (rooted, acyclic)
• Functor: C = relational category (bipartite: tables + foreign keys)
• Graph: C = graph category (general directed graph)

Each inner type implements AcsetOps, which provides restrict, extend, element_count, and shape_name through a unified trait interface. The methods on Instance below dispatch to those implementations.

Variants

WType(WInstance)

Tree-shaped instance (W-type).

Functor(FInstance)

Relational/tabular instance (set-valued functor).

Graph(GInstance)

Graph-shaped instance (most general form).

Implementations

impl Instance

pub const fn shape_name(&self) -> &'static str

Returns the shape name.

pub fn restrict( &self, src_schema: &Schema, tgt_schema: &Schema, migration: &CompiledMigration, ) -> Result<Self, RestrictError>

Restrict this instance along a compiled migration.

Dispatches to the shape-specific restrict pipeline.

Errors

Returns an error if the restrict pipeline fails.

pub fn extend( &self, tgt_schema: &Schema, migration: &CompiledMigration, ) -> Result<Self, RestrictError>

Extend this instance along a compiled migration (Sigma_F).

Dispatches to the shape-specific extend pipeline.

Errors

Returns an error if the extend pipeline fails.

pub fn element_count(&self) -> usize

Returns the number of elements (nodes/rows/vertices) in this instance.

pub const fn as_wtype(&self) -> Option<&WInstance>

Try to get a reference to the inner WInstance.

pub const fn as_functor(&self) -> Option<&FInstance>

Try to get a reference to the inner FInstance.

pub const fn as_graph(&self) -> Option<&GInstance>

Try to get a reference to the inner GInstance.

Trait Implementations

impl Clone for Instance

fn clone(&self) -> Instance

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Instance

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Instance

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<FInstance> for Instance

fn from(f: FInstance) -> Self

Converts to this type from the input type.

impl From<GInstance> for Instance

fn from(g: GInstance) -> Self

Converts to this type from the input type.

impl From<WInstance> for Instance

fn from(w: WInstance) -> Self

Converts to this type from the input type.

impl Serialize for Instance

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

where __S: Serializer,

Serialize this value into the given Serde serializer.