if a.result.Error != nil {
		return types.NewErr("composited variable %q fails to compile: %v", a.name, a.result.Error)
	}

	v, details, err := a.result.Program.ContextEval(a.context, a.activation)
	if details == nil {
		return types.NewErr("unable to get evaluation details of variable %q", a.name)
	}
	costPtr := details.ActualCost()
	if costPtr == nil {
		return types.NewErr("unable to calculate cost of variable %q", a.name)
	}

}

func (d Quantity) ConvertToType(typeVal ref.Type) ref.Val {
	switch typeVal {
	case quantityTypeValue:
		return d
	case types.TypeType:
		return quantityTypeValue
	default:
		return types.NewErr("type conversion error from '%s' to '%s'", quantityTypeValue, typeVal)
	}
}

func (d Quantity) Equal(other ref.Val) ref.Val {
	otherDur, ok := other.(Quantity)
	if !ok {
		return types.MaybeNoSuchOverloadErr(other)

}

func (d *Format) ConvertToType(typeVal ref.Type) ref.Val {
	switch typeVal {
	case FormatType:
		return d
	case types.TypeType:
		return FormatType
	default:
		return types.NewErr("type conversion error from '%s' to '%s'", FormatType, typeVal)
	}
}

func (d *Format) Equal(other ref.Val) ref.Val {
	otherDur, ok := other.(*Format)
	if !ok {
		return types.MaybeNoSuchOverloadErr(other)
	}

func (v *ObjectVal) ConvertToType(typeValue ref.Type) ref.Val {
	switch typeValue {
	case v.typeRef:
		return v
	case types.TypeType:
		return v.typeRef.CELType()
	}
	return types.NewErr("unsupported conversion into %v", typeValue)
}

// Equal returns true if the `other` value has the same type and content as the implementing struct.
func (v *ObjectVal) Equal(other ref.Val) ref.Val {

	variablesMap.Append("dict", func(_ *MapValue) ref.Val {
		evalCounter++
		v, err := compileAndRun(env, activation, `{"a": "a"}`)
		if err != nil {
			return types.NewErr(err.Error())
		}
		return v
	})

	// iterate the map with .all
	exp = `variables.all(n, n != "")`
	v, err = compileAndRun(env, activation, exp)
	if err != nil {
		t.Fatalf("%q: %v", exp, err)
	}