Function optionalDecls

interpreter/prune_test.go:595–633

(t *testing.T)

}

func optionalDecls(t *testing.T) []*decls.FunctionDecl {
	paramType := types.NewTypeParamType("T")
	optionalType := types.NewOptionalType(paramType)
	return []*decls.FunctionDecl{
		funcDecl(t, "optional.none",
			decls.Overload("optional_none", []*types.Type{}, optionalType,
				decls.FunctionBinding(func(args ...ref.Val) ref.Val {
					return types.OptionalNone
				}),
			),
		),
		funcDecl(t, "optional.of",
			decls.Overload("optional_of_value", []*types.Type{paramType}, optionalType,
				decls.UnaryBinding(func(val ref.Val) ref.Val {
					return types.OptionalOf(val)
				}),
			),
		),
		funcDecl(t, "_[?_]",
			decls.Overload("map_optindex_optional_value", []*types.Type{
				types.NewMapType(types.NewTypeParamType("K"), paramType),
				types.NewTypeParamType("K"),
			}, optionalType),
		),
		funcDecl(t, "last", decls.Overload("list_last", []*types.Type{paramType}, optionalType,
			decls.UnaryBinding(func(v ref.Val) ref.Val {
				list := v.(traits.Lister)
				sz := list.Size().Value().(int64)

				if sz == 0 {
					return types.OptionalNone
				}

				return types.OptionalOf(list.Get(types.Int(sz - 1)))
			}),
		),
		),
	}
}