Hilbish/readline/readline.go

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package readline
import (
"bytes"
"errors"
"fmt"
"os"
"regexp"
"syscall"
)
var rxMultiline = regexp.MustCompile(`[\r\n]+`)
// Readline displays the readline prompt.
// It will return a string (user entered data) or an error.
func (rl *Instance) Readline() (string, error) {
fd := int(os.Stdin.Fd())
state, err := MakeRaw(fd)
if err != nil {
return "", err
}
defer Restore(fd, state)
// In Vim mode, we always start in Input mode. The prompt needs this.
rl.modeViMode = VimInsert
// Prompt Init
// Here we have to either print prompt
// and return new line (multiline)
if rl.Multiline {
fmt.Println(rl.mainPrompt)
}
rl.stillOnRefresh = false
rl.computePrompt() // initialise the prompt for first print
// Line Init & Cursor
rl.line = []rune{}
rl.currentComp = []rune{} // No virtual completion yet
rl.lineComp = []rune{} // So no virtual line either
rl.modeViMode = VimInsert
rl.pos = 0
rl.posY = 0
rl.tcPrefix = ""
// Completion && infos init
rl.resetInfoText()
rl.resetTabCompletion()
rl.getInfoText()
// History Init
// We need this set to the last command, so that we can access it quickly
rl.histOffset = 0
rl.viUndoHistory = []undoItem{{line: "", pos: 0}}
// Multisplit
if len(rl.multisplit) > 0 {
r := []rune(rl.multisplit[0])
if len(r) >= 1 {
rl.editorInput(r)
}
rl.carridgeReturn()
if len(rl.multisplit) > 1 {
rl.multisplit = rl.multisplit[1:]
} else {
rl.multisplit = []string{}
}
return string(rl.line), nil
}
// Finally, print any info or completions
// if the TabCompletion engines so desires
rl.renderHelpers()
// Start handling keystrokes. Classified by subject for most.
for {
rl.viUndoSkipAppend = false
b := make([]byte, 1024)
var i int
if !rl.skipStdinRead {
var err error
i, err = os.Stdin.Read(b)
if err != nil {
if errors.Is(err, syscall.EAGAIN) {
err = syscall.SetNonblock(syscall.Stdin, false)
if err == nil {
continue
}
}
return "", err
}
}
rl.skipStdinRead = false
r := []rune(string(b))
if rl.RawInputCallback != nil {
rl.RawInputCallback(r[:i])
}
if isMultiline(r[:i]) || len(rl.multiline) > 0 {
rl.multiline = append(rl.multiline, b[:i]...)
if i == len(b) {
continue
}
if !rl.allowMultiline(rl.multiline) {
rl.multiline = []byte{}
continue
}
s := string(rl.multiline)
rl.multisplit = rxMultiline.Split(s, -1)
r = []rune(rl.multisplit[0])
rl.modeViMode = VimInsert
rl.editorInput(r)
rl.carridgeReturn()
rl.multiline = []byte{}
if len(rl.multisplit) > 1 {
rl.multisplit = rl.multisplit[1:]
} else {
rl.multisplit = []string{}
}
return string(rl.line), nil
}
s := string(r[:i])
if rl.evtKeyPress[s] != nil {
rl.clearHelpers()
ret := rl.evtKeyPress[s](s, rl.line, rl.pos)
rl.clearLine()
rl.line = append(ret.NewLine, []rune{}...)
rl.updateHelpers() // rl.echo
rl.pos = ret.NewPos
if ret.ClearHelpers {
rl.resetHelpers()
} else {
rl.updateHelpers()
}
if len(ret.InfoText) > 0 {
rl.infoText = ret.InfoText
rl.clearHelpers()
rl.renderHelpers()
}
if !ret.ForwardKey {
continue
}
if ret.CloseReadline {
rl.clearHelpers()
return string(rl.line), nil
}
}
// Before anything: we can never be both in modeTabCompletion and compConfirmWait,
// because we need to confirm before entering completion. If both are true, there
// is a problem (at least, the user has escaped the confirm hint some way).
if (rl.modeTabCompletion && rl.searchMode != HistoryFind) && rl.compConfirmWait {
rl.compConfirmWait = false
}
switch b[0] {
// Errors & Returns --------------------------------------------------------------------------------
case charCtrlC:
if rl.modeTabCompletion {
rl.resetVirtualComp(true)
rl.resetHelpers()
rl.renderHelpers()
continue
}
rl.clearHelpers()
return "", CtrlC
case charEOF: // ctrl d
if len(rl.line) == 0 {
rl.clearHelpers()
return "", EOF
}
if rl.modeTabFind {
rl.backspaceTabFind()
} else {
if (rl.pos < len(rl.line)) {
rl.deleteBackspace(true)
}
}
// Clear screen
case charCtrlL:
print(seqClearScreen)
print(seqCursorTopLeft)
if rl.Multiline {
fmt.Println(rl.mainPrompt)
}
print(seqClearScreenBelow)
rl.resetInfoText()
rl.getInfoText()
rl.renderHelpers()
// Line Editing ------------------------------------------------------------------------------------
case charCtrlU:
if rl.modeTabCompletion {
rl.resetVirtualComp(true)
}
// Delete everything from the beginning of the line to the cursor position
rl.saveBufToRegister(rl.line[:rl.pos])
rl.deleteToBeginning()
rl.resetHelpers()
rl.updateHelpers()
case charCtrlK:
if rl.modeTabCompletion {
rl.resetVirtualComp(true)
}
// Delete everything after the cursor position
rl.saveBufToRegister(rl.line[rl.pos:])
rl.deleteToEnd()
rl.resetHelpers()
rl.updateHelpers()
case charBackspace, charBackspace2:
// When currently in history completion, we refresh and automatically
// insert the first (filtered) candidate, virtually
if rl.modeAutoFind && rl.searchMode == HistoryFind {
rl.resetVirtualComp(true)
rl.backspaceTabFind()
// Then update the printing, with the new candidate
rl.updateVirtualComp()
rl.renderHelpers()
rl.viUndoSkipAppend = true
continue
}
// Normal completion search does only refresh the search pattern and the comps
if rl.modeTabFind || rl.modeAutoFind {
rl.resetVirtualComp(false)
rl.backspaceTabFind()
rl.renderHelpers()
rl.viUndoSkipAppend = true
} else {
// Always cancel any virtual completion
rl.resetVirtualComp(false)
// Vim mode has different behaviors
if rl.InputMode == Vim {
if rl.modeViMode == VimInsert {
rl.backspace(false)
} else if rl.pos != 0 {
rl.pos--
}
rl.renderHelpers()
continue
}
// Else emacs deletes a character
rl.backspace(false)
rl.renderHelpers()
}
// Emacs Bindings ----------------------------------------------------------------------------------
case charCtrlW:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
// This is only available in Insert mode
if rl.modeViMode != VimInsert {
continue
}
rl.saveToRegister(rl.viJumpB(tokeniseLine))
rl.viDeleteByAdjust(rl.viJumpB(tokeniseLine))
rl.updateHelpers()
case charCtrlY:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
// paste after the cursor position
rl.viUndoSkipAppend = true
buffer := rl.pasteFromRegister()
rl.insert(buffer)
rl.updateHelpers()
case charCtrlE:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
// This is only available in Insert mode
if rl.modeViMode != VimInsert {
continue
}
if len(rl.line) > 0 {
rl.pos = len(rl.line)
}
rl.viUndoSkipAppend = true
rl.updateHelpers()
case charCtrlA:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
// This is only available in Insert mode
if rl.modeViMode != VimInsert {
continue
}
rl.viUndoSkipAppend = true
rl.pos = 0
rl.updateHelpers()
// Command History ---------------------------------------------------------------------------------
// NOTE: The alternative history source is triggered by Alt+r,
// but because this is a sequence, the alternative history code
// trigger is in the below rl.escapeSeq(r) function.
case charCtrlR:
rl.resetVirtualComp(false)
// For some modes only, if we are in vim Keys mode,
// we toogle back to insert mode. For others, we return
// without getting the completions.
if rl.modeViMode != VimInsert {
rl.modeViMode = VimInsert
rl.computePrompt()
}
rl.mainHist = true // false before
rl.searchMode = HistoryFind
rl.modeAutoFind = true
rl.modeTabCompletion = true
rl.modeTabFind = true
rl.updateTabFind([]rune{})
rl.updateVirtualComp()
rl.renderHelpers()
rl.viUndoSkipAppend = true
// Tab Completion & Completion Search ---------------------------------------------------------------
case charTab:
// The user cannot show completions if currently in Vim Normal mode
if rl.InputMode == Vim && rl.modeViMode != VimInsert {
continue
}
// If we have asked for completions, already printed, and we want to move selection.
if rl.modeTabCompletion && !rl.compConfirmWait {
rl.tabCompletionSelect = true
rl.moveTabCompletionHighlight(1, 0)
rl.updateVirtualComp()
rl.renderHelpers()
rl.viUndoSkipAppend = true
} else {
// Else we might be asked to confirm printing (if too many suggestions), or not.
rl.getTabCompletion()
// If too many completions and no yet confirmed, ask user for completion
// comps, lines := rl.getCompletionCount()
// if ((lines > GetTermLength()) || (lines > rl.MaxTabCompleterRows)) && !rl.compConfirmWait {
// sentence := fmt.Sprintf("%s show all %d completions (%d lines) ? tab to confirm",
// FOREWHITE, comps, lines)
// rl.promptCompletionConfirm(sentence)
// continue
// }
rl.compConfirmWait = false
rl.modeTabCompletion = true
// Also here, if only one candidate is available, automatically
// insert it and don't bother printing completions.
// Quit the tab completion mode to avoid asking to the user
// to press Enter twice to actually run the command.
if rl.hasOneCandidate() {
rl.insertCandidate()
// Refresh first, and then quit the completion mode
rl.updateHelpers() // REDUNDANT WITH getTabCompletion()
rl.viUndoSkipAppend = true
rl.resetTabCompletion()
continue
}
rl.updateHelpers() // REDUNDANT WITH getTabCompletion()
rl.viUndoSkipAppend = true
continue
}
case charCtrlF:
rl.resetVirtualComp(true)
if !rl.modeTabCompletion {
rl.modeTabCompletion = true
}
if rl.compConfirmWait {
rl.resetHelpers()
}
// Both these settings apply to when we already
// are in completion mode and when we are not.
rl.searchMode = CompletionFind
rl.modeAutoFind = true
// Switch from history to completion search
if rl.modeTabCompletion && rl.searchMode == HistoryFind {
rl.searchMode = CompletionFind
}
rl.updateTabFind([]rune{})
rl.viUndoSkipAppend = true
case charCtrlG:
if rl.modeAutoFind && rl.searchMode == HistoryFind {
rl.resetVirtualComp(false)
rl.resetTabFind()
rl.resetHelpers()
rl.renderHelpers()
continue
}
if rl.modeAutoFind {
rl.resetTabFind()
rl.resetHelpers()
rl.renderHelpers()
}
2022-04-13 20:58:36 +00:00
case charCtrlUnderscore:
rl.undoLast()
rl.viUndoSkipAppend = true
case '\r':
fallthrough
case '\n':
if rl.modeTabCompletion {
cur := rl.getCurrentGroup()
// Check that there is a group indeed, as we might have no completions.
if cur == nil {
rl.clearHelpers()
rl.resetTabCompletion()
rl.renderHelpers()
continue
}
// IF we have a prefix and completions printed, but no candidate
// (in which case the completion is ""), we immediately return.
completion := cur.getCurrentCell(rl)
prefix := len(rl.tcPrefix)
if prefix > len(completion) {
rl.carridgeReturn()
return string(rl.line), nil
}
// Else, we insert the completion candidate in the real input line.
// By default we add a space, unless completion group asks otherwise.
rl.compAddSpace = true
rl.resetVirtualComp(false)
// If we were in history completion, immediately execute the line.
if rl.modeAutoFind && rl.searchMode == HistoryFind {
rl.carridgeReturn()
return string(rl.line), nil
}
// Reset completions and update input line
rl.clearHelpers()
rl.resetTabCompletion()
rl.renderHelpers()
continue
}
rl.carridgeReturn()
return string(rl.line), nil
// Vim --------------------------------------------------------------------------------------
case charEscape:
// If we were waiting for completion confirm, abort
if rl.compConfirmWait {
rl.compConfirmWait = false
rl.renderHelpers()
}
// We always refresh the completion candidates, except if we are currently
// cycling through them, because then it would just append the candidate.
if rl.modeTabCompletion {
if string(r[:i]) != seqShiftTab &&
string(r[:i]) != seqForwards && string(r[:i]) != seqBackwards &&
string(r[:i]) != seqUp && string(r[:i]) != seqDown {
// basically only applies except on 1st ctrl r open
// so if we have not explicitly selected something
// (tabCompletionSelect is false) drop virtual completion
rl.resetVirtualComp(!rl.tabCompletionSelect)
}
}
// Once helpers of all sorts are cleared, we can process
// the change of input modes, etc.
rl.escapeSeq(r[:i])
// Dispatch --------------------------------------------------------------------------------------
default:
// If we were waiting for completion confirm, abort
if rl.compConfirmWait {
rl.resetVirtualComp(false)
rl.compConfirmWait = false
rl.renderHelpers()
}
// When currently in history completion, we refresh and automatically
// insert the first (filtered) candidate, virtually
if rl.modeAutoFind && rl.searchMode == HistoryFind {
rl.resetVirtualComp(true)
rl.updateTabFind(r[:i])
rl.updateVirtualComp()
rl.renderHelpers()
rl.viUndoSkipAppend = true
continue
}
// Not sure that CompletionFind is useful, nor one of the other two
if rl.modeAutoFind || rl.modeTabFind {
rl.resetVirtualComp(false)
rl.updateTabFind(r[:i])
rl.renderHelpers()
rl.viUndoSkipAppend = true
continue
} else {
rl.resetVirtualComp(false)
rl.editorInput(r[:i])
if len(rl.multiline) > 0 && rl.modeViMode == VimKeys {
rl.skipStdinRead = true
}
}
rl.clearHelpers()
}
rl.undoAppendHistory()
}
}
// editorInput is an unexported function used to determine what mode of text
// entry readline is currently configured for and then update the line entries
// accordingly.
func (rl *Instance) editorInput(r []rune) {
if len(r) == 0 {
return
}
switch rl.modeViMode {
case VimKeys:
rl.vi(r[0])
rl.refreshVimStatus()
case VimDelete:
rl.viDelete(r[0])
rl.refreshVimStatus()
case VimReplaceOnce:
rl.modeViMode = VimKeys
rl.deleteX()
rl.insert([]rune{r[0]})
rl.refreshVimStatus()
case VimReplaceMany:
for _, char := range r {
if rl.pos != len(rl.line) {
rl.deleteX()
}
rl.insert([]rune{char})
}
rl.refreshVimStatus()
default:
// Don't insert control keys
if r[0] >= 1 && r[0] <= 31 {
return
}
// We reset the history nav counter each time we come here:
// We don't need it when inserting text.
rl.histNavIdx = 0
rl.insert(r)
rl.writeHintText()
}
rl.echoRightPrompt()
if len(rl.multisplit) == 0 {
rl.syntaxCompletion()
}
}
// viEscape - In case th user is using Vim input, and the escape sequence has not
// been handled by other cases, we dispatch it to Vim and handle a few cases here.
func (rl *Instance) viEscape(r []rune) {
// Sometimes the escape sequence is interleaved with another one,
// but key strokes might be in the wrong order, so we double check
// and escape the mode only if needed.
if rl.modeViMode == VimInsert && len(r) == 1 && r[0] == 27 {
if len(rl.line) > 0 && rl.pos > 0 {
rl.pos--
}
rl.modeViMode = VimKeys
rl.viIteration = ""
rl.refreshVimStatus()
return
}
}
func (rl *Instance) escapeSeq(r []rune) {
switch string(r) {
// Vim escape sequences & dispatching --------------------------------------------------------
case string(charEscape):
switch {
case rl.modeAutoFind:
rl.resetVirtualComp(true)
rl.resetTabFind()
rl.clearHelpers()
rl.resetTabCompletion()
rl.resetHelpers()
rl.renderHelpers()
case rl.modeTabFind:
rl.resetVirtualComp(true)
rl.resetTabFind()
rl.resetTabCompletion()
case rl.modeTabCompletion:
rl.clearHelpers()
rl.resetTabCompletion()
rl.renderHelpers()
default:
// No matter the input mode, we exit
// any completion confirm if there's one.
if rl.compConfirmWait {
rl.compConfirmWait = false
rl.clearHelpers()
rl.renderHelpers()
return
}
// If we are in Vim mode, the escape key has its usage.
// Otherwise in emacs mode the escape key does nothing.
if rl.InputMode == Vim {
rl.viEscape(r)
return
}
// This refreshed and actually prints the new Vim status
// if we have indeed change the Vim mode.
rl.clearHelpers()
rl.renderHelpers()
}
rl.viUndoSkipAppend = true
// Tab completion movements ------------------------------------------------------------------
case seqShiftTab:
if rl.modeTabCompletion && !rl.compConfirmWait {
rl.tabCompletionReverse = true
rl.moveTabCompletionHighlight(-1, 0)
rl.updateVirtualComp()
rl.tabCompletionReverse = false
rl.renderHelpers()
rl.viUndoSkipAppend = true
return
}
case seqUp:
if rl.modeTabCompletion {
rl.tabCompletionSelect = true
rl.tabCompletionReverse = true
rl.moveTabCompletionHighlight(-1, 0)
rl.updateVirtualComp()
rl.tabCompletionReverse = false
rl.renderHelpers()
return
}
rl.mainHist = true
rl.walkHistory(1)
moveCursorForwards(len(rl.line) - rl.pos)
rl.pos = len(rl.line)
case seqDown:
if rl.modeTabCompletion {
rl.tabCompletionSelect = true
rl.moveTabCompletionHighlight(1, 0)
rl.updateVirtualComp()
rl.renderHelpers()
return
}
rl.mainHist = true
rl.walkHistory(-1)
moveCursorForwards(len(rl.line) - rl.pos)
rl.pos = len(rl.line)
case seqForwards:
if rl.modeTabCompletion {
rl.tabCompletionSelect = true
rl.moveTabCompletionHighlight(1, 0)
rl.updateVirtualComp()
rl.renderHelpers()
return
}
if (rl.modeViMode == VimInsert && rl.pos < len(rl.line)) ||
(rl.modeViMode != VimInsert && rl.pos < len(rl.line)-1) {
rl.moveCursorByAdjust(1)
}
rl.updateHelpers()
rl.viUndoSkipAppend = true
case seqBackwards:
if rl.modeTabCompletion {
rl.tabCompletionSelect = true
rl.tabCompletionReverse = true
rl.moveTabCompletionHighlight(-1, 0)
rl.updateVirtualComp()
rl.tabCompletionReverse = false
rl.renderHelpers()
return
}
rl.moveCursorByAdjust(-1)
rl.viUndoSkipAppend = true
rl.updateHelpers()
// Registers -------------------------------------------------------------------------------
case seqAltQuote:
if rl.modeViMode != VimInsert {
return
}
rl.modeTabCompletion = true
rl.modeAutoFind = true
rl.searchMode = RegisterFind
// Else we might be asked to confirm printing (if too many suggestions), or not.
rl.getTabCompletion()
rl.viUndoSkipAppend = true
rl.renderHelpers()
// Movement -------------------------------------------------------------------------------
case seqCtrlLeftArrow:
rl.moveCursorByAdjust(rl.viJumpB(tokeniseLine))
rl.updateHelpers()
return
case seqCtrlRightArrow:
rl.insert(rl.hintText)
rl.moveCursorByAdjust(rl.viJumpW(tokeniseLine))
rl.updateHelpers()
return
case seqDelete,seqDelete2:
if rl.modeTabFind {
rl.backspaceTabFind()
} else {
if (rl.pos < len(rl.line)) {
rl.deleteBackspace(true)
}
}
case seqHome, seqHomeSc:
if rl.modeTabCompletion {
return
}
rl.moveCursorByAdjust(-rl.pos)
rl.updateHelpers()
rl.viUndoSkipAppend = true
case seqEnd, seqEndSc:
if rl.modeTabCompletion {
return
}
rl.moveCursorByAdjust(len(rl.line) - rl.pos)
rl.updateHelpers()
rl.viUndoSkipAppend = true
case seqAltB:
if rl.modeTabCompletion {
return
}
// This is only available in Insert mode
if rl.modeViMode != VimInsert {
return
}
move := rl.emacsBackwardWord(tokeniseLine)
rl.moveCursorByAdjust(-move)
rl.updateHelpers()
case seqAltF:
if rl.modeTabCompletion {
return
}
// This is only available in Insert mode
if rl.modeViMode != VimInsert {
return
}
move := rl.emacsForwardWord(tokeniseLine)
rl.moveCursorByAdjust(move)
rl.updateHelpers()
case seqAltR:
rl.resetVirtualComp(false)
// For some modes only, if we are in vim Keys mode,
// we toogle back to insert mode. For others, we return
// without getting the completions.
if rl.modeViMode != VimInsert {
rl.modeViMode = VimInsert
}
rl.mainHist = false // true before
rl.searchMode = HistoryFind
rl.modeAutoFind = true
rl.modeTabCompletion = true
rl.modeTabFind = true
rl.updateTabFind([]rune{})
rl.viUndoSkipAppend = true
case seqAltBackspace:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
// This is only available in Insert mode
if rl.modeViMode != VimInsert {
return
}
rl.saveToRegister(rl.viJumpB(tokeniseLine))
rl.viDeleteByAdjust(rl.viJumpB(tokeniseLine))
rl.updateHelpers()
case seqCtrlDelete, seqCtrlDelete2, seqAltD:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
rl.saveToRegister(rl.emacsForwardWord(tokeniseLine))
// vi delete, emacs forward, funny huh
rl.viDeleteByAdjust(rl.emacsForwardWord(tokeniseLine))
rl.updateHelpers()
case seqAltDelete:
if rl.modeTabCompletion {
rl.resetVirtualComp(false)
}
rl.saveToRegister(-rl.emacsBackwardWord(tokeniseLine))
rl.viDeleteByAdjust(-rl.emacsBackwardWord(tokeniseLine))
rl.updateHelpers()
default:
if rl.modeTabFind {
return
}
// alt+numeric append / delete
if len(r) == 2 && '1' <= r[1] && r[1] <= '9' {
if rl.modeViMode == VimDelete {
rl.viDelete(r[1])
return
}
line, err := rl.mainHistory.GetLine(rl.mainHistory.Len() - 1)
if err != nil {
return
}
if !rl.mainHist {
line, err = rl.altHistory.GetLine(rl.altHistory.Len() - 1)
if err != nil {
return
}
}
tokens, _, _ := tokeniseSplitSpaces([]rune(line), 0)
pos := int(r[1]) - 48 // convert ASCII to integer
if pos > len(tokens) {
return
}
rl.insert([]rune(tokens[pos-1]))
} else {
rl.viUndoSkipAppend = true
}
}
}
func (rl *Instance) carridgeReturn() {
rl.moveCursorByAdjust(len(rl.line))
rl.updateHelpers()
rl.clearHelpers()
print("\r\n")
if rl.HistoryAutoWrite {
var err error
// Main history
if rl.mainHistory != nil {
rl.histPos, err = rl.mainHistory.Write(string(rl.line))
if err != nil {
print(err.Error() + "\r\n")
}
}
// Alternative history
if rl.altHistory != nil {
rl.histPos, err = rl.altHistory.Write(string(rl.line))
if err != nil {
print(err.Error() + "\r\n")
}
}
}
}
func isMultiline(r []rune) bool {
for i := range r {
if (r[i] == '\r' || r[i] == '\n') && i != len(r)-1 {
return true
}
}
return false
}
func (rl *Instance) allowMultiline(data []byte) bool {
rl.clearHelpers()
printf("\r\nWARNING: %d bytes of multiline data was dumped into the shell!", len(data))
for {
print("\r\nDo you wish to proceed (yes|no|preview)? [y/n/p] ")
b := make([]byte, 1024)
i, err := os.Stdin.Read(b)
if err != nil {
return false
}
s := string(b[:i])
print(s)
switch s {
case "y", "Y":
print("\r\n" + rl.mainPrompt)
return true
case "n", "N":
print("\r\n" + rl.mainPrompt)
return false
case "p", "P":
preview := string(bytes.Replace(data, []byte{'\r'}, []byte{'\r', '\n'}, -1))
if rl.SyntaxHighlighter != nil {
preview = rl.SyntaxHighlighter([]rune(preview))
}
print("\r\n" + preview)
default:
print("\r\nInvalid response. Please answer `y` (yes), `n` (no) or `p` (preview)")
}
}
}