Struct ApplicationEvaluator 

pub struct ApplicationEvaluator<'a, R: TypeResolver> { /* private fields */ }

Evaluator for generic type applications.

This evaluator takes a type application like Box<string> and:

1. Looks up the definition of Box (via the resolver)
2. Gets its type parameters
3. Substitutes the type arguments
4. Returns the resulting type

Type Resolver

The evaluator uses a TypeResolver to handle symbol resolution. This abstraction allows the solver to remain independent of the binder/checker:

• resolve_ref(symbol) - get the body type of a type alias/interface
• get_type_params(symbol) - get the type parameters for a symbol

Implementations

impl<'a, R: TypeResolver> ApplicationEvaluator<'a, R>

pub fn new(interner: &'a dyn TypeDatabase, resolver: &'a R) -> Self

Create a new application evaluator.

pub fn clear_cache(&self)

Clear the evaluation cache. Call this when contextual type changes to ensure fresh evaluation.

pub fn evaluate(&self, type_id: TypeId) -> ApplicationResult

Evaluate an Application type by resolving the base symbol and instantiating.

This handles types like Store<ExtractState<R>> by:

1. Resolving the base type reference to get its body
2. Getting the type parameters
3. Instantiating the body with the provided type arguments
4. Recursively evaluating the result

Returns

• ApplicationResult::Resolved(type_id) - successfully evaluated
• ApplicationResult::NotApplication(type_id) - input was not an application type
• ApplicationResult::DepthExceeded(type_id) - recursion limit reached
• ApplicationResult::ResolutionFailed(type_id) - symbol resolution failed

pub fn evaluate_or_original(&self, type_id: TypeId) -> TypeId

Evaluate a type and return the result, falling back to the original type.

This is a convenience method that unwraps the ApplicationResult.