inject

type Applicator interface {
	// Apply maps dependencies in the Type map to each field in the struct that is
	// tagged with "inject". Returns an error if the injection fails.
	Apply(interface{}) error
}

type FastInvoker interface {
	// Invoke attempts to call the `interface{}` provided as interface method,
	// providing dependencies for function arguments based on Type. Returns a slice
	// of reflect.Value representing the returned values of the function. Returns an
	// error if the injection fails.
	Invoke([]interface{}) ([]reflect.Value, error)
}

type Injector interface {
	Applicator
	Invoker
	TypeMapper
	Provider
	// SetParent sets the parent of the injector. If the injector cannot find a
	// dependency in its Type map it will check its parent before returning an
	// error.
	SetParent(Injector)
	GetParent() Injector
}

type Invoker interface {
	// Invoke attempts to call the `interface{}` provided as a function, providing
	// dependencies for function arguments based on Type. Returns a slice of
	// reflect.Value representing the returned values of the function. Returns an
	// error if the injection fails.
	Invoke(interface{}) ([]reflect.Value, error)
}

type Provider interface {
	Provide(interface{}) error
}

type TypeMapper interface {
	// Map maps the `interface{}` values based on their immediate type from
	// reflect.TypeOf.
	Map(...interface{}) TypeMapper
	// MapTo maps the `interface{}` value based on the pointer of an Interface
	// provided. This is really only useful for mapping a value as an interface, as
	// interfaces cannot at this time be referenced directly without a pointer.
	MapTo(interface{}, interface{}) TypeMapper
	// Set provides a possibility to directly insert a mapping based on type and
	// value. This makes it possible to directly map type arguments not possible to
	// instantiate with reflect like unidirectional channels.
	Set(reflect.Type, reflect.Value) TypeMapper
	// Value returns the reflect.Value that is mapped to the reflect.Type. It
	// returns a zeroed reflect.Value if the Type has not been mapped.
	Value(reflect.Type) reflect.Value
}