Struct FeatureStructureAlgebra 

pub struct FeatureStructureAlgebra { /* private fields */ }

Feature-structure algebra compatible with Alto’s general operations.

Literal operation symbols parse to FeatureStructure values. Malformed literals and failed operations make evaluation undefined. The remap_* extension keeps multi-attribute selection linear, so it can be used in inverse homomorphisms without repeating a source variable.

Implementations

impl FeatureStructureAlgebra

pub fn with_signature(signature: Signature) -> Self

Build an algebra by classifying every operation in signature.

pub fn filter(&self) -> FeatureStructureFilter<'_>

Return an automaton accepting successfully evaluated feature terms.

Trait Implementations

impl Algebra for FeatureStructureAlgebra

type InternalValue = FeatureStructure

Efficient internal value domain used by evaluate and decomposition.

type Value = FeatureStructure

Standalone public value produced for output by evaluate_term.

type ParseError = FeatureStructureParseError

Error returned when parsing a textual object representation.

fn signature(&self) -> &Signature

Return the operation signature used by this algebra.

fn evaluate( &self, symbol: Symbol, children: &[Self::InternalValue], ) -> Option<Self::InternalValue>

Evaluate an operation over child internal values.

fn parse_object( &mut self, input: &str, ) -> Result<Self::InternalValue, Self::ParseError>

Parse a textual representation into an internal value.

fn to_external(&self, value: &Self::InternalValue) -> Self::Value

Map an internal value to its standalone public form.

fn visualize(&self, value: &Self::Value) -> VisualRepresentation

Convert a public value into this algebra’s preferred GUI-neutral representation.

fn evaluate_term_internal( &self, arena: &TreeArena<Symbol>, root: Tree, ) -> Option<Self::InternalValue>

Evaluate a term tree bottom-up to an internal value, applying evaluate at every node (e.g. a homomorphic image produced from a derivation tree).

fn evaluate_term( &self, arena: &TreeArena<Symbol>, root: Tree, ) -> Option<Self::Value>

Evaluate a term tree to its public value (bottom-up evaluate, then to_external).

fn is_valid_value(&self, _value: &Self::InternalValue) -> bool

Return whether value is a valid internal value.

fn decompose_default( &self, value: Self::InternalValue, ) -> EvaluatingDecompositionAutomaton<'_, Self>

where Self: Sized,

Build the default evaluating decomposition automaton for value.

impl Clone for FeatureStructureAlgebra

fn clone(&self) -> FeatureStructureAlgebra

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FeatureStructureAlgebra

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

Formats the value using the given formatter.