Struct Instance 

pub struct Instance {
    pub class: Name,
    pub ty: Expr,
    pub priority: i32,
    pub methods: HashMap<String, Expr>,
    pub instance_name: Option<Name>,
    pub is_local: bool,
}

An instance of a type class.

For example, instance : Add Nat is an instance of Add for the type Nat.

Fields

class: Name

The class this is an instance of.

ty: Expr

The type argument(s) for this instance.

priority: i32

Search priority (lower number = searched first).

methods: HashMap<String, Expr>

Implementations of each method (method name → expression).

instance_name: Option<Name>

Optional name for the instance declaration.

is_local: bool

Whether this is a local (hypothetical) instance.

Implementations

impl Instance

pub fn new(class: Name, ty: Expr) -> Self

Create a new anonymous instance with default priority.

pub fn named(class: Name, ty: Expr, name: Name) -> Self

Create a named instance.

pub fn with_priority(self, priority: i32) -> Self

Set the priority.

pub fn as_local(self) -> Self

Mark as a local instance.

pub fn add_method_impl( &mut self, method_name: impl Into<String>, impl_expr: Expr, )

Add an implementation for a method.

pub fn get_method_impl(&self, method_name: &str) -> Option<&Expr>

Look up the implementation of a method.

pub fn implements_all(&self, class: &TypeClass) -> bool

Check whether all methods of the given class are implemented.

pub fn implemented_count(&self) -> usize

Number of implemented methods.

pub fn is_named(&self) -> bool

Check whether this instance has a name.

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.