Add ExecuteOnEnterCallback

_example/bang-executor/main.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+ "fmt"
+ "unicode/utf8"
+
+ "github.com/elk-language/go-prompt"
+)
+
+func main() {
+ p := prompt.New(
+ executor,
+ prompt.WithExecuteOnEnterCallback(ExecuteOnEnter),
+ )
+
+ p.Run()
+}
+
+func ExecuteOnEnter(input string) bool {
+ char, _ := utf8.DecodeLastRuneInString(input)
+ return char == '!'
+}
+
+func executor(s string) {
+ fmt.Println("You printed: " + s)
+}

_example/http-prompt/main.go

@@ -92,11 +92,13 @@ var suggestions = []prompt.Suggest{
  {"X-XSRF-TOKEN", "Prevent cross-site request forgery"},
 }
 
-func livePrefix() (string, bool) {
- if ctx.url.Path == "/" {
- return "", false
+func livePrefix(defaultPrefix string) prompt.PrefixCallback {
+ return func() string {
+ if ctx.url.Path == "/" {
+ return defaultPrefix
+ }
+ return ctx.url.String() + "> "
  }
- return ctx.url.String() + "> ", true
 }
 
 func executor(in string) {
@@ -183,8 +185,7 @@ func main() {
 
  p := prompt.New(
  executor,
- prompt.WithPrefix(u.String()+"> "),
- prompt.WithLivePrefix(livePrefix),
+ prompt.WithPrefixCallback(livePrefix(u.String()+"> ")),
  prompt.WithTitle("http-prompt"),
  prompt.WithCompleter(completer),
  )

_example/live-prefix/main.go

@@ -6,20 +6,15 @@ import (
  prompt "github.com/elk-language/go-prompt"
 )
 
-var LivePrefixState struct {
- LivePrefix string
- IsEnable bool
-}
+var LivePrefix string = ">>> "
 
 func executor(in string) {
  fmt.Println("Your input: " + in)
  if in == "" {
- LivePrefixState.IsEnable = false
- LivePrefixState.LivePrefix = in
+ LivePrefix = ">>> "
  return
  }
- LivePrefixState.LivePrefix = in + "> "
- LivePrefixState.IsEnable = true
+ LivePrefix = in + "> "
 }
 
 func completer(in prompt.Document) []prompt.Suggest {
@@ -32,15 +27,14 @@ func completer(in prompt.Document) []prompt.Suggest {
  return prompt.FilterHasPrefix(s, in.GetWordBeforeCursor(), true)
 }
 
-func changeLivePrefix() (string, bool) {
- return LivePrefixState.LivePrefix, LivePrefixState.IsEnable
+func changeLivePrefix() string {
+ return LivePrefix
 }
 
 func main() {
  p := prompt.New(
  executor,
- prompt.WithPrefix(">>> "),
- prompt.WithLivePrefix(changeLivePrefix),
+ prompt.WithPrefixCallback(changeLivePrefix),
  prompt.WithTitle("live-prefix-example"),
  prompt.WithCompleter(completer),
  )

constructor.go

@@ -4,6 +4,9 @@ package prompt
 // prompt.New accepts any number of options (this is functional option pattern).
 type Option func(prompt *Prompt) error
 
+// Callback function that returns a prompt prefix.
+type PrefixCallback func() (prefix string)
+
 // WithCompleter is an option that sets a custom Completer object.
 func WithCompleter(c Completer) Option {
  return func(p *Prompt) error {
@@ -12,59 +15,59 @@ func WithCompleter(c Completer) Option {
  }
 }
 
-// WithReader to set a custom Reader object. An argument should implement Reader interface.
-func WithReader(x Reader) Option {
+// WithReader can be used to set a custom Reader object.
+func WithReader(r Reader) Option {
  return func(p *Prompt) error {
- p.reader = x
+ p.reader = r
  return nil
  }
 }
 
-// WithWriter to set a custom Writer object. An argument should implement Writer interface.
-func WithWriter(x Writer) Option {
+// WithWriter can be used to set a custom Writer object.
+func WithWriter(w Writer) Option {
  return func(p *Prompt) error {
- registerWriter(x)
- p.renderer.out = x
+ registerWriter(w)
+ p.renderer.out = w
  return nil
  }
 }
 
-// WithTitle to set title displayed at the header bar of terminal.
-func WithTitle(x string) Option {
+// WithTitle can be used to set the title displayed at the header bar of the terminal.
+func WithTitle(t string) Option {
  return func(p *Prompt) error {
- p.renderer.title = x
+ p.renderer.title = t
  return nil
  }
 }
 
-// WithPrefix to set prefix string.
-func WithPrefix(x string) Option {
+// WithPrefix can be used to set a prefix string for the prompt.
+func WithPrefix(prefix string) Option {
  return func(p *Prompt) error {
- p.renderer.prefix = x
+ p.renderer.prefixCallback = func() string { return prefix }
  return nil
  }
 }
 
-// WithInitialBufferText to set the initial buffer text
-func WithInitialBufferText(x string) Option {
+// WithInitialText can be used to set the initial buffer text.
+func WithInitialText(text string) Option {
  return func(p *Prompt) error {
- p.buf.InsertText(x, false, true)
+ p.buf.InsertText(text, false, true)
  return nil
  }
 }
 
-// WithCompletionWordSeparator to set word separators. Enable only ' ' if empty.
-func WithCompletionWordSeparator(x string) Option {
+// WithCompletionWordSeparator can be used to set word separators. Enable only ' ' if empty.
+func WithCompletionWordSeparator(sep string) Option {
  return func(p *Prompt) error {
- p.completion.wordSeparator = x
+ p.completion.wordSeparator = sep
  return nil
  }
 }
 
-// WithLivePrefix to change the prefix dynamically by callback function
-func WithLivePrefix(f func() (prefix string, useLivePrefix bool)) Option {
+// WithPrefixCallback can be used to change the prefix dynamically by a callback function.
+func WithPrefixCallback(f PrefixCallback) Option {
  return func(p *Prompt) error {
- p.renderer.livePrefixCallback = f
+ p.renderer.prefixCallback = f
  return nil
  }
 }
@@ -282,6 +285,24 @@ func WithLexer(lex Lexer) Option {
  }
 }
 
+// WithExecuteOnEnterCallback can be used to set
+// a custom callback function that determines whether an Enter key
+// should trigger the Executor or add a newline to the user input buffer.
+func WithExecuteOnEnterCallback(fn ExecuteOnEnterCallback) Option {
+ return func(p *Prompt) error {
+ p.executeOnEnterCallback = fn
+ return nil
+ }
+}
+
+func DefaultExecuteOnEnterCallback(input string) bool {
+ return true
+}
+
+func DefaultPrefixCallback() string {
+ return "> "
+}
+
 // New returns a Prompt with powerful auto-completion.
 func New(executor Executor, opts ...Option) *Prompt {
  defaultWriter := NewStdoutWriter()
@@ -290,9 +311,8 @@ func New(executor Executor, opts ...Option) *Prompt {
  pt := &Prompt{
  reader: NewStdinReader(),
  renderer: &Render{
- prefix: "> ",
  out: defaultWriter,
- livePrefixCallback: func() (string, bool) { return "", false },
+ prefixCallback:  DefaultPrefixCallback,
  prefixTextColor: Blue,
  prefixBGColor: DefaultColor,
  inputTextColor: DefaultColor,
@@ -310,11 +330,12 @@ func New(executor Executor, opts ...Option) *Prompt {
  scrollbarThumbColor: DarkGray,
  scrollbarBGColor: Cyan,
  },
- buf: NewBuffer(),
- executor: executor,
- history: NewHistory(),
- completion: NewCompletionManager(6),
- keyBindMode: EmacsKeyBind, // All the above assume that bash is running in the default Emacs setting
+ buf: NewBuffer(),
+ executor: executor,
+ history: NewHistory(),
+ completion: NewCompletionManager(6),
+ executeOnEnterCallback: DefaultExecuteOnEnterCallback,
+ keyBindMode: EmacsKeyBind, // All the above assume that bash is running in the default Emacs setting
  }
 
  for _, opt := range opts {

prompt.go

@@ -23,25 +23,33 @@ type Executor func(string)
 // Exit means exit go-prompt (not the overall Go program)
 type ExitChecker func(in string, breakline bool) bool
 
+// ExecuteOnEnterCallback is a function that receives
+// user input after Enter has been pressed
+// and determines whether the input should be executed.
+// If this function returns true, the Executor callback will be called
+// otherwise a newline will be added to the buffer containing user input.
+type ExecuteOnEnterCallback func(input string) bool
+
 // Completer is a function that returns
 // a slice of suggestions for the given Document.
 type Completer func(Document) []Suggest
 
 // Prompt is a core struct of go-prompt.
 type Prompt struct {
- reader Reader
- buf *Buffer
- renderer *Render
- executor Executor
- history *History
- lexer Lexer
- completion *CompletionManager
- keyBindings []KeyBind
- ASCIICodeBindings []ASCIICodeBind
- keyBindMode KeyBindMode
- completionOnDown bool
- exitChecker ExitChecker
- skipClose bool
+ reader Reader
+ buf *Buffer
+ renderer *Render
+ executor Executor
+ history *History
+ lexer Lexer
+ completion *CompletionManager
+ keyBindings []KeyBind
+ ASCIICodeBindings []ASCIICodeBind
+ keyBindMode KeyBindMode
+ completionOnDown bool
+ exitChecker ExitChecker
+ executeOnEnterCallback ExecuteOnEnterCallback
+ skipClose bool
 }
 
 // UserInput is the struct that contains the user input context.
@@ -137,8 +145,12 @@ func (p *Prompt) feed(b []byte) (shouldExit bool, userInput *UserInput) {
 
  switch key {
  case Enter, ControlJ, ControlM:
- p.renderer.BreakLine(p.buf, p.lexer)
+ if !p.executeOnEnterCallback(p.buf.Text()) {
+ p.buf.NewLine(false)
+ break
+ }
 
+ p.renderer.BreakLine(p.buf, p.lexer)
  userInput = &UserInput{input: p.buf.Text()}
  p.buf = NewBuffer()
  if userInput.input != "" {

render.go

@@ -10,13 +10,12 @@ import (
 
 // Render to render prompt information from state of Buffer.
 type Render struct {
- out Writer
- prefix string
- livePrefixCallback func() (prefix string, useLivePrefix bool)
- breakLineCallback func(*Document)
- title string
- row uint16
- col uint16
+ out Writer
+ prefixCallback PrefixCallback
+ breakLineCallback func(*Document)
+ title string
+ row uint16
+ col uint16
 
  previousCursor Position
 
@@ -50,10 +49,7 @@ func (r *Render) Setup() {
 // getCurrentPrefix to get current prefix.
 // If live-prefix is enabled, return live-prefix.
 func (r *Render) getCurrentPrefix() string {
- if prefix, ok := r.livePrefixCallback(); ok {
- return prefix
- }
- return r.prefix
+ return r.prefixCallback()
 }
 
 func (r *Render) renderPrefix() {

render_test.go

@@ -73,11 +73,10 @@ func TestFormatCompletion(t *testing.T) {
 func TestBreakLineCallback(t *testing.T) {
  var i int
  r := &Render{
- prefix: "> ",
  out: &PosixWriter{
  fd: syscall.Stdin, // "write" to stdin just so we don't mess with the output of the tests
  },
- livePrefixCallback: func() (string, bool) { return "", false },
+ prefixCallback:  DefaultPrefixCallback,
  prefixTextColor: Blue,
  prefixBGColor: DefaultColor,
  inputTextColor: DefaultColor,

shortcut.go

@@ -3,10 +3,9 @@ package prompt
 func NoopExecutor(in string) {}
 
 // Input get the input data from the user and return it.
-func Input(prefix string, opts ...Option) string {
+func Input(opts ...Option) string {
  pt := New(NoopExecutor)
  pt.renderer.prefixTextColor = DefaultColor
- pt.renderer.prefix = prefix
 
  for _, opt := range opts {
  if err := opt(pt); err != nil {