unexport Field, add type converter AsField

field.go

@@ -9,7 +9,7 @@ import (
 	"github.com/charmbracelet/huh"
 )
 
-type Field struct {
+type field struct {
 	*Model
 
 	value *FilePath
@@ -39,163 +39,162 @@ type Field struct {
 // KeyMap(keys *huh.KeyMap) huh.Field
 // Width(width int) huh.Field
 
-func Value(value string) Option[*Field] {
-	return func(f *Field) *Field { return f.WithValue(value) }
+// Value returns an Option that sets the value of a field.
+func Value(value string) Option[*field] {
+	return func(f *field) *field { return f.WithValue(value) }
 }
 
-func Key(key string) Option[*Field] {
-	return func(f *Field) *Field { return f.WithKey(key) }
+// Key returns an Option that sets the key of a field.
+func Key(key string) Option[*field] {
+	return func(f *field) *field { return f.WithKey(key) }
 }
 
-func Heading(heading string) Option[*Field] {
-	return func(f *Field) *Field { return f.WithHeading(heading) }
+// Heading returns an Option that sets the heading of a field.
+func Heading(heading string) Option[*field] {
+	return func(f *field) *field { return f.WithHeading(heading) }
 }
 
-func Caption(caption string) Option[*Field] {
-	return func(f *Field) *Field { return f.WithCaption(caption) }
+// Caption returns an Option that sets the caption of a field.
+func Caption(caption string) Option[*field] {
+	return func(f *field) *field { return f.WithCaption(caption) }
 }
 
-func Validate(validate func(FilePath) error) Option[*Field] {
-	return func(f *Field) *Field { return f.WithValidate(validate) }
+// Validate returns an Option that sets the validation function of a field.
+func Validate(validate func(FilePath) error) Option[*field] {
+	return func(f *field) *field { return f.WithValidate(validate) }
 }
 
-// Field returns a new Field of the receiver Model.
-//
-// Field implements both its epynomous interface and the Model interface used in
-// the Bubble Tea framework (module packages "huh" & "bubbletea", respectively).
-func (m *Model) Field(options ...Option[*Field]) *Field {
-	filter := textinput.New()
-	filter.Prompt = "/"
-
-	return &Field{
-		Model:    m,
-		value:    new(FilePath),
-		validate: func(FilePath) error { return nil },
-		filter:   filter,
-	}
+// Prompt returns an Option that sets the prompt of a field.
+func Prompt(prompt string) Option[*field] {
+	return func(f *field) *field { return f.WithPrompt(prompt) }
 }
 
-// Init initializes the Field.
-func (f *Field) Init() tea.Cmd {
+// Init initializes the field.
+func (f *field) Init() tea.Cmd {
 	return f.Model.Init()
 }
 
-func (f *Field) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+func (f *field) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	_, cmd := f.Model.Update(msg)
 	return f, cmd
 }
 
-func (f *Field) View() string {
+func (f *field) View() string {
 	return f.Model.View()
 }
 
-// Blur blurs the Field.
-func (f *Field) Blur() tea.Cmd {
+// Blur blurs the field.
+func (f *field) Blur() tea.Cmd {
 	f.isFocused = false
 	f.err = f.validate(*f.value)
 	return nil
 }
 
-// Focus focuses the Field.
-func (f *Field) Focus() tea.Cmd {
+// Focus focuses the field.
+func (f *field) Focus() tea.Cmd {
 	f.isFocused = true
 	return nil
 }
 
-// Error returns the error of the Field.
-func (f *Field) Error() error {
+// Error returns the error of the field.
+func (f *field) Error() error {
 	return f.err
 }
 
-// Run runs the Field.
-func (f *Field) Run() error {
+// Run runs the field.
+func (f *field) Run() error {
 	if f.accessible {
 		return f.runAccessible()
 	}
 	return newRunError(huh.Run(f))
 }
 
-// KeyBinds returns the keybindings for the Field.
-func (f *Field) KeyBinds() []key.Binding {
+// KeyBinds returns the keybindings for the field.
+func (f *field) KeyBinds() []key.Binding {
 	return []key.Binding{} // f.keys.bindings()
 }
 
 // With returns the receiver with the given options applied.
-func (f *Field) With(options ...Option[*Field]) *Field {
+func (f *field) With(options ...Option[*field]) *field {
 	for _, option := range options {
 		f = option(f)
 	}
 	return f
 }
 
-// WithTheme sets the theme of the Field.
-func (f *Field) WithTheme(theme *huh.Theme) huh.Field {
+// WithTheme sets the theme of the field.
+func (f *field) WithTheme(theme *huh.Theme) huh.Field {
 	f.theme = theme
 	f.filter.Cursor.Style = f.theme.Focused.TextInput.Cursor
 	f.filter.PromptStyle = f.theme.Focused.TextInput.Prompt
 	return f
 }
 
-// WithAccessible sets the accessible mode of the Field.
-func (f *Field) WithAccessible(accessible bool) huh.Field {
+// WithAccessible sets the accessible mode of the field.
+func (f *field) WithAccessible(accessible bool) huh.Field {
 	f.accessible = accessible
 	return f
 }
 
-// WithKeyMap sets the keymap on a Field.
-func (f *Field) WithKeyMap(keys *huh.KeyMap) huh.Field {
+// WithKeyMap sets the keymap on a field.
+func (f *field) WithKeyMap(keys *huh.KeyMap) huh.Field {
 	// TBD
 	return f
 }
 
-// WithWidth sets the width of the Field.
-func (f *Field) WithWidth(width int) huh.Field {
+// WithWidth sets the width of the field.
+func (f *field) WithWidth(width int) huh.Field {
 	f.width = width
 	return f
 }
 
 // GetKey returns the key of the field.
-func (f *Field) GetKey() string {
+func (f *field) GetKey() string {
 	return f.key
 }
 
 // GetValue returns the value of the field.
-func (f *Field) GetValue() any {
+func (f *field) GetValue() any {
 	return f.value.path()
 }
 
-// Value sets the value of the Field.
-func (f *Field) WithValue(value string) *Field {
+// WithValue sets the value of the field.
+func (f *field) WithValue(value string) *field {
 	f.value = f.value.init(value)
 	return f
 }
 
-// Key sets the key of the Field which can be used to retrieve the value
-// after submission.
-func (f *Field) WithKey(key string) *Field {
+// WithKey sets the key of the field.
+func (f *field) WithKey(key string) *field {
 	f.key = key
 	return f
 }
 
-// Heading sets the heading of the Field.
-func (f *Field) WithHeading(heading string) *Field {
+// WithHeading sets the heading of the field.
+func (f *field) WithHeading(heading string) *field {
 	f.heading = heading
 	return f
 }
 
-// Caption sets the caption of the Field.
-func (f *Field) WithCaption(caption string) *Field {
+// WithCaption sets the caption of the field.
+func (f *field) WithCaption(caption string) *field {
 	f.caption = caption
 	return f
 }
 
-// Validate sets the validation function of the Field.
-func (f *Field) WithValidate(validate func(FilePath) error) *Field {
+// WithValidate sets the validation function of the field.
+func (f *field) WithValidate(validate func(FilePath) error) *field {
 	f.validate = validate
 	return f
 }
 
-func (f *Field) runAccessible() error {
+// WithPrompt sets the prompt of the field.
+func (f *field) WithPrompt(prompt string) *field {
+	f.filter.Prompt = prompt
+	return f
+}
+
+func (f *field) runAccessible() error {
 	var sb strings.Builder
 	sb.WriteString(f.theme.Focused.Title.Render(f.heading) + "\n")
 
@@ -221,11 +220,11 @@ func (f *Field) runAccessible() error {
 	return nil
 }
 
-func (f *Field) setIsFiltered(isFiltered bool) {
+func (f *field) setIsFiltered(isFiltered bool) {
 	f.isFiltered = isFiltered
 }
 
-func (f *Field) filterFunc(option string) bool {
+func (f *field) filterFunc(option string) bool {
 	// XXX: remove diacritics or allow customization of filter function.
 	return strings.Contains(
 		strings.ToLower(option),

option.go

@@ -1,6 +1,6 @@
 package walk
 
 // Optional is a type with which Option arguments and methods can be applied.
-type Optional interface{ *Model | *Field }
+type Optional interface{ *Model | *field }
 
 type Option[O Optional] func(O) O

walk.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/antonmedv/clipboard"
 	"github.com/charmbracelet/bubbles/key"
+	"github.com/charmbracelet/bubbles/textinput"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
 	"github.com/sahilm/fuzzy"
@@ -34,6 +35,7 @@ type Model struct {
 	path              string              // Current dir path we are looking at.
 	files             []fs.DirEntry       // Files we are looking at.
 	err               error               // Error while listing files.
+	field             *field              // Bubble Tea Huh form field.
 	keys              *KeyMap             // Key bindings.
 	st                *Styles             // Rendering attributes.
 	cmdline           []string            // Command line to open files.
@@ -75,12 +77,16 @@ type (
 func New(options ...Option[*Model]) *Model {
 	m := (&Model{positions: make(map[string]position)}).With(options...)
 
+	// Use the default key bindings if none provided.
 	if m.keys == nil {
 		m.keys = m.keys.Default()
 	}
+
+	// Use the default style if none provided.
 	if m.st == nil {
 		m.st = m.st.Default()
 	}
+
 	return m
 }
 
@@ -114,6 +120,13 @@ func Keys(keys *KeyMap) Option[*Model] {
 	return func(m *Model) *Model { return m.WithKeys(keys) }
 }
 
+// Field returns an Option that configures Model as a form field.
+//
+// This Option must be provided to initialize Model as a form field.
+func Field(options ...Option[*field]) Option[*Model] {
+	return func(m *Model) *Model { return m.withField(options...) }
+}
+
 // Kill exits the program with the given exit status.
 func Kill(status int) { os.Exit(status) }
 
@@ -508,6 +521,9 @@ func (m *Model) View() string {
 // Exit exits the program with the receiver's current exit status.
 func (m *Model) Exit() { Kill(m.status) }
 
+// Field returns the receiver's field used in a form.
+func (m *Model) Field() *field { return m.field }
+
 // Value returns the path of the currently selected file.
 func (m *Model) Value() string {
 	path, _ := m.filePath()
@@ -560,6 +576,33 @@ func (m *Model) WithKeys(keys *KeyMap) *Model {
 	return m
 }
 
+// withField returns the receiver with the given options applied to its field.
+//
+// This method must be called to initialize walk as a form field, and it must
+// be called when initializing a new Model by providing a field Option.
+//
+// The types Model and field both implement different interfaces from the
+// Bubble Tea framework. field is a specialization of Model that allows walk to
+// be used as a discrete field in a Bubble Tea "huh" form application:
+//
+//	|  Interface  | `field` | `Model` |
+//	|------------:|:-------:|:-------:|
+//	| `tea.Model` |    ✓    |    ✓    |
+//	| `huh.Field` |    ✓    |         |
+func (m *Model) withField(options ...Option[*field]) *Model {
+	m.field = (&field{
+		Model:    m,
+		value:    new(FilePath),
+		validate: func(FilePath) error { return nil },
+		filter:   textinput.New(),
+	}).With(options...)
+	return m
+}
+
+func (m *Model) AsField(options ...Option[*field]) *field {
+	return m.withField(options...).field
+}
+
 func (m *Model) moveUp() {
 	m.r--
 	if m.r < 0 {