1package starlarkstruct 2 3import ( 4 "fmt" 5 6 "go.starlark.net/starlark" 7) 8 9// A Module is a named collection of values, 10// typically a suite of functions imported by a load statement. 11// 12// It differs from Struct primarily in that its string representation 13// does not enumerate its fields. 14type Module struct { 15 Name string 16 Members starlark.StringDict 17} 18 19var _ starlark.HasAttrs = (*Module)(nil) 20 21func (m *Module) Attr(name string) (starlark.Value, error) { return m.Members[name], nil } 22func (m *Module) AttrNames() []string { return m.Members.Keys() } 23func (m *Module) Freeze() { m.Members.Freeze() } 24func (m *Module) Hash() (uint32, error) { return 0, fmt.Errorf("unhashable: %s", m.Type()) } 25func (m *Module) String() string { return fmt.Sprintf("<module %q>", m.Name) } 26func (m *Module) Truth() starlark.Bool { return true } 27func (m *Module) Type() string { return "module" } 28 29// MakeModule may be used as the implementation of a Starlark built-in 30// function, module(name, **kwargs). It returns a new module with the 31// specified name and members. 32func MakeModule(thread *starlark.Thread, b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) { 33 var name string 34 if err := starlark.UnpackPositionalArgs(b.Name(), args, nil, 1, &name); err != nil { 35 return nil, err 36 } 37 members := make(starlark.StringDict, len(kwargs)) 38 for _, kwarg := range kwargs { 39 k := string(kwarg[0].(starlark.String)) 40 members[k] = kwarg[1] 41 } 42 return &Module{name, members}, nil 43} 44