Struct AlgebraicDataType 

pub struct AlgebraicDataType { /* private fields */ }

A tagged-union type: a named set of variants, each with its own fields.

The kernel defines the Shape match/binding protocol; this type is the pattern organ’s concrete declaration of an algebraic data type. It produces VariantConstructors for building tagged values and a kernel Shape (AdtShape) for matching them. See the crate README for the protocol-versus-behavior boundary.

Examples

use std::sync::Arc;
use sim_kernel::Symbol;
use sim_lib_pattern::{AlgebraicDataType, VariantDeclaration};

let maybe = AlgebraicDataType::new(
    Symbol::qualified("adt", "Maybe"),
    vec![
        VariantDeclaration::nullary(Symbol::qualified("maybe", "Nothing")),
        VariantDeclaration::nullary(Symbol::qualified("maybe", "Just")),
    ],
)
.unwrap();
assert_eq!(maybe.constructors().len(), 2);
assert!(maybe.constructor(&Symbol::qualified("maybe", "Just")).is_some());

Implementations

impl AlgebraicDataType

pub fn new(symbol: Symbol, variants: Vec<VariantDeclaration>) -> Result<Self>

Builds an ADT from its name and variants.

Errors

Returns an error if two variants share a tag symbol.

pub fn symbol(&self) -> &Symbol

Returns the ADT name symbol.

pub fn variants(&self) -> impl Iterator<Item = &VariantDeclaration>

Iterates the declared variants in tag order.

pub fn constructor(&self, variant: &Symbol) -> Option<VariantConstructor>

Returns the constructor for variant, or None if it is not declared.

pub fn constructors(&self) -> Vec<VariantConstructor>

Returns a constructor for every declared variant.

pub fn shape(&self) -> Arc<dyn Shape>

Returns the kernel Shape that matches any value of this ADT.

Trait Implementations

impl Clone for AlgebraicDataType

fn clone(&self) -> AlgebraicDataType

Returns a duplicate of the value.

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

Performs copy-assignment from source.