bsc/vendor/github.com/peterh/liner/line.go
Péter Szilágyi 289b30715d Godeps, vendor: convert dependency management to trash (#3198)
This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.
2016-10-28 19:05:01 +02:00

1034 lines
24 KiB
Go

// +build windows linux darwin openbsd freebsd netbsd
package liner
import (
"container/ring"
"errors"
"fmt"
"io"
"strings"
"unicode"
"unicode/utf8"
)
type action int
const (
left action = iota
right
up
down
home
end
insert
del
pageUp
pageDown
f1
f2
f3
f4
f5
f6
f7
f8
f9
f10
f11
f12
altB
altF
altY
shiftTab
wordLeft
wordRight
winch
unknown
)
const (
ctrlA = 1
ctrlB = 2
ctrlC = 3
ctrlD = 4
ctrlE = 5
ctrlF = 6
ctrlG = 7
ctrlH = 8
tab = 9
lf = 10
ctrlK = 11
ctrlL = 12
cr = 13
ctrlN = 14
ctrlO = 15
ctrlP = 16
ctrlQ = 17
ctrlR = 18
ctrlS = 19
ctrlT = 20
ctrlU = 21
ctrlV = 22
ctrlW = 23
ctrlX = 24
ctrlY = 25
ctrlZ = 26
esc = 27
bs = 127
)
const (
beep = "\a"
)
type tabDirection int
const (
tabForward tabDirection = iota
tabReverse
)
func (s *State) refresh(prompt []rune, buf []rune, pos int) error {
if s.multiLineMode {
return s.refreshMultiLine(prompt, buf, pos)
} else {
return s.refreshSingleLine(prompt, buf, pos)
}
}
func (s *State) refreshSingleLine(prompt []rune, buf []rune, pos int) error {
s.cursorPos(0)
_, err := fmt.Print(string(prompt))
if err != nil {
return err
}
pLen := countGlyphs(prompt)
bLen := countGlyphs(buf)
pos = countGlyphs(buf[:pos])
if pLen+bLen < s.columns {
_, err = fmt.Print(string(buf))
s.eraseLine()
s.cursorPos(pLen + pos)
} else {
// Find space available
space := s.columns - pLen
space-- // space for cursor
start := pos - space/2
end := start + space
if end > bLen {
end = bLen
start = end - space
}
if start < 0 {
start = 0
end = space
}
pos -= start
// Leave space for markers
if start > 0 {
start++
}
if end < bLen {
end--
}
startRune := len(getPrefixGlyphs(buf, start))
line := getPrefixGlyphs(buf[startRune:], end-start)
// Output
if start > 0 {
fmt.Print("{")
}
fmt.Print(string(line))
if end < bLen {
fmt.Print("}")
}
// Set cursor position
s.eraseLine()
s.cursorPos(pLen + pos)
}
return err
}
func (s *State) refreshMultiLine(prompt []rune, buf []rune, pos int) error {
promptColumns := countMultiLineGlyphs(prompt, s.columns, 0)
totalColumns := countMultiLineGlyphs(buf, s.columns, promptColumns)
totalRows := (totalColumns + s.columns - 1) / s.columns
maxRows := s.maxRows
if totalRows > s.maxRows {
s.maxRows = totalRows
}
cursorRows := s.cursorRows
if cursorRows == 0 {
cursorRows = 1
}
/* First step: clear all the lines used before. To do so start by
* going to the last row. */
if maxRows-cursorRows > 0 {
s.moveDown(maxRows - cursorRows)
}
/* Now for every row clear it, go up. */
for i := 0; i < maxRows-1; i++ {
s.cursorPos(0)
s.eraseLine()
s.moveUp(1)
}
/* Clean the top line. */
s.cursorPos(0)
s.eraseLine()
/* Write the prompt and the current buffer content */
if _, err := fmt.Print(string(prompt)); err != nil {
return err
}
if _, err := fmt.Print(string(buf)); err != nil {
return err
}
/* If we are at the very end of the screen with our prompt, we need to
* emit a newline and move the prompt to the first column. */
cursorColumns := countMultiLineGlyphs(buf[:pos], s.columns, promptColumns)
if cursorColumns == totalColumns && totalColumns%s.columns == 0 {
s.emitNewLine()
s.cursorPos(0)
totalRows++
if totalRows > s.maxRows {
s.maxRows = totalRows
}
}
/* Move cursor to right position. */
cursorRows = (cursorColumns + s.columns) / s.columns
if s.cursorRows > 0 && totalRows-cursorRows > 0 {
s.moveUp(totalRows - cursorRows)
}
/* Set column. */
s.cursorPos(cursorColumns % s.columns)
s.cursorRows = cursorRows
return nil
}
func (s *State) resetMultiLine(prompt []rune, buf []rune, pos int) {
columns := countMultiLineGlyphs(prompt, s.columns, 0)
columns = countMultiLineGlyphs(buf[:pos], s.columns, columns)
columns += 2 // ^C
cursorRows := (columns + s.columns) / s.columns
if s.maxRows-cursorRows > 0 {
for i := 0; i < s.maxRows-cursorRows; i++ {
fmt.Println() // always moves the cursor down or scrolls the window up as needed
}
}
s.maxRows = 1
s.cursorRows = 0
}
func longestCommonPrefix(strs []string) string {
if len(strs) == 0 {
return ""
}
longest := strs[0]
for _, str := range strs[1:] {
for !strings.HasPrefix(str, longest) {
longest = longest[:len(longest)-1]
}
}
// Remove trailing partial runes
longest = strings.TrimRight(longest, "\uFFFD")
return longest
}
func (s *State) circularTabs(items []string) func(tabDirection) (string, error) {
item := -1
return func(direction tabDirection) (string, error) {
if direction == tabForward {
if item < len(items)-1 {
item++
} else {
item = 0
}
} else if direction == tabReverse {
if item > 0 {
item--
} else {
item = len(items) - 1
}
}
return items[item], nil
}
}
func calculateColumns(screenWidth int, items []string) (numColumns, numRows, maxWidth int) {
for _, item := range items {
if len(item) >= screenWidth {
return 1, len(items), screenWidth - 1
}
if len(item) >= maxWidth {
maxWidth = len(item) + 1
}
}
numColumns = screenWidth / maxWidth
numRows = len(items) / numColumns
if len(items)%numColumns > 0 {
numRows++
}
if len(items) <= numColumns {
maxWidth = 0
}
return
}
func (s *State) printedTabs(items []string) func(tabDirection) (string, error) {
numTabs := 1
prefix := longestCommonPrefix(items)
return func(direction tabDirection) (string, error) {
if len(items) == 1 {
return items[0], nil
}
if numTabs == 2 {
if len(items) > 100 {
fmt.Printf("\nDisplay all %d possibilities? (y or n) ", len(items))
prompt:
for {
next, err := s.readNext()
if err != nil {
return prefix, err
}
if key, ok := next.(rune); ok {
switch key {
case 'n', 'N':
return prefix, nil
case 'y', 'Y':
break prompt
case ctrlC, ctrlD, cr, lf:
s.restartPrompt()
}
}
}
}
fmt.Println("")
numColumns, numRows, maxWidth := calculateColumns(s.columns, items)
for i := 0; i < numRows; i++ {
for j := 0; j < numColumns*numRows; j += numRows {
if i+j < len(items) {
if maxWidth > 0 {
fmt.Printf("%-*.[1]*s", maxWidth, items[i+j])
} else {
fmt.Printf("%v ", items[i+j])
}
}
}
fmt.Println("")
}
} else {
numTabs++
}
return prefix, nil
}
}
func (s *State) tabComplete(p []rune, line []rune, pos int) ([]rune, int, interface{}, error) {
if s.completer == nil {
return line, pos, rune(esc), nil
}
head, list, tail := s.completer(string(line), pos)
if len(list) <= 0 {
return line, pos, rune(esc), nil
}
hl := utf8.RuneCountInString(head)
if len(list) == 1 {
s.refresh(p, []rune(head+list[0]+tail), hl+utf8.RuneCountInString(list[0]))
return []rune(head + list[0] + tail), hl + utf8.RuneCountInString(list[0]), rune(esc), nil
}
direction := tabForward
tabPrinter := s.circularTabs(list)
if s.tabStyle == TabPrints {
tabPrinter = s.printedTabs(list)
}
for {
pick, err := tabPrinter(direction)
if err != nil {
return line, pos, rune(esc), err
}
s.refresh(p, []rune(head+pick+tail), hl+utf8.RuneCountInString(pick))
next, err := s.readNext()
if err != nil {
return line, pos, rune(esc), err
}
if key, ok := next.(rune); ok {
if key == tab {
direction = tabForward
continue
}
if key == esc {
return line, pos, rune(esc), nil
}
}
if a, ok := next.(action); ok && a == shiftTab {
direction = tabReverse
continue
}
return []rune(head + pick + tail), hl + utf8.RuneCountInString(pick), next, nil
}
// Not reached
return line, pos, rune(esc), nil
}
// reverse intelligent search, implements a bash-like history search.
func (s *State) reverseISearch(origLine []rune, origPos int) ([]rune, int, interface{}, error) {
p := "(reverse-i-search)`': "
s.refresh([]rune(p), origLine, origPos)
line := []rune{}
pos := 0
foundLine := string(origLine)
foundPos := origPos
getLine := func() ([]rune, []rune, int) {
search := string(line)
prompt := "(reverse-i-search)`%s': "
return []rune(fmt.Sprintf(prompt, search)), []rune(foundLine), foundPos
}
history, positions := s.getHistoryByPattern(string(line))
historyPos := len(history) - 1
for {
next, err := s.readNext()
if err != nil {
return []rune(foundLine), foundPos, rune(esc), err
}
switch v := next.(type) {
case rune:
switch v {
case ctrlR: // Search backwards
if historyPos > 0 && historyPos < len(history) {
historyPos--
foundLine = history[historyPos]
foundPos = positions[historyPos]
} else {
fmt.Print(beep)
}
case ctrlS: // Search forward
if historyPos < len(history)-1 && historyPos >= 0 {
historyPos++
foundLine = history[historyPos]
foundPos = positions[historyPos]
} else {
fmt.Print(beep)
}
case ctrlH, bs: // Backspace
if pos <= 0 {
fmt.Print(beep)
} else {
n := len(getSuffixGlyphs(line[:pos], 1))
line = append(line[:pos-n], line[pos:]...)
pos -= n
// For each char deleted, display the last matching line of history
history, positions := s.getHistoryByPattern(string(line))
historyPos = len(history) - 1
if len(history) > 0 {
foundLine = history[historyPos]
foundPos = positions[historyPos]
} else {
foundLine = ""
foundPos = 0
}
}
case ctrlG: // Cancel
return origLine, origPos, rune(esc), err
case tab, cr, lf, ctrlA, ctrlB, ctrlD, ctrlE, ctrlF, ctrlK,
ctrlL, ctrlN, ctrlO, ctrlP, ctrlQ, ctrlT, ctrlU, ctrlV, ctrlW, ctrlX, ctrlY, ctrlZ:
fallthrough
case 0, ctrlC, esc, 28, 29, 30, 31:
return []rune(foundLine), foundPos, next, err
default:
line = append(line[:pos], append([]rune{v}, line[pos:]...)...)
pos++
// For each keystroke typed, display the last matching line of history
history, positions = s.getHistoryByPattern(string(line))
historyPos = len(history) - 1
if len(history) > 0 {
foundLine = history[historyPos]
foundPos = positions[historyPos]
} else {
foundLine = ""
foundPos = 0
}
}
case action:
return []rune(foundLine), foundPos, next, err
}
s.refresh(getLine())
}
}
// addToKillRing adds some text to the kill ring. If mode is 0 it adds it to a
// new node in the end of the kill ring, and move the current pointer to the new
// node. If mode is 1 or 2 it appends or prepends the text to the current entry
// of the killRing.
func (s *State) addToKillRing(text []rune, mode int) {
// Don't use the same underlying array as text
killLine := make([]rune, len(text))
copy(killLine, text)
// Point killRing to a newNode, procedure depends on the killring state and
// append mode.
if mode == 0 { // Add new node to killRing
if s.killRing == nil { // if killring is empty, create a new one
s.killRing = ring.New(1)
} else if s.killRing.Len() >= KillRingMax { // if killring is "full"
s.killRing = s.killRing.Next()
} else { // Normal case
s.killRing.Link(ring.New(1))
s.killRing = s.killRing.Next()
}
} else {
if s.killRing == nil { // if killring is empty, create a new one
s.killRing = ring.New(1)
s.killRing.Value = []rune{}
}
if mode == 1 { // Append to last entry
killLine = append(s.killRing.Value.([]rune), killLine...)
} else if mode == 2 { // Prepend to last entry
killLine = append(killLine, s.killRing.Value.([]rune)...)
}
}
// Save text in the current killring node
s.killRing.Value = killLine
}
func (s *State) yank(p []rune, text []rune, pos int) ([]rune, int, interface{}, error) {
if s.killRing == nil {
return text, pos, rune(esc), nil
}
lineStart := text[:pos]
lineEnd := text[pos:]
var line []rune
for {
value := s.killRing.Value.([]rune)
line = make([]rune, 0)
line = append(line, lineStart...)
line = append(line, value...)
line = append(line, lineEnd...)
pos = len(lineStart) + len(value)
s.refresh(p, line, pos)
next, err := s.readNext()
if err != nil {
return line, pos, next, err
}
switch v := next.(type) {
case rune:
return line, pos, next, nil
case action:
switch v {
case altY:
s.killRing = s.killRing.Prev()
default:
return line, pos, next, nil
}
}
}
return line, pos, esc, nil
}
// Prompt displays p and returns a line of user input, not including a trailing
// newline character. An io.EOF error is returned if the user signals end-of-file
// by pressing Ctrl-D. Prompt allows line editing if the terminal supports it.
func (s *State) Prompt(prompt string) (string, error) {
return s.PromptWithSuggestion(prompt, "", 0)
}
// PromptWithSuggestion displays prompt and an editable text with cursor at
// given position. The cursor will be set to the end of the line if given position
// is negative or greater than length of text. Returns a line of user input, not
// including a trailing newline character. An io.EOF error is returned if the user
// signals end-of-file by pressing Ctrl-D.
func (s *State) PromptWithSuggestion(prompt string, text string, pos int) (string, error) {
if s.inputRedirected || !s.terminalSupported {
return s.promptUnsupported(prompt)
}
if s.outputRedirected {
return "", ErrNotTerminalOutput
}
s.historyMutex.RLock()
defer s.historyMutex.RUnlock()
fmt.Print(prompt)
p := []rune(prompt)
var line = []rune(text)
historyEnd := ""
prefixHistory := s.getHistoryByPrefix(string(line))
historyPos := len(prefixHistory)
historyAction := false // used to mark history related actions
killAction := 0 // used to mark kill related actions
defer s.stopPrompt()
if pos < 0 || len(text) < pos {
pos = len(text)
}
if len(line) > 0 {
s.refresh(p, line, pos)
}
restart:
s.startPrompt()
s.getColumns()
mainLoop:
for {
next, err := s.readNext()
haveNext:
if err != nil {
if s.shouldRestart != nil && s.shouldRestart(err) {
goto restart
}
return "", err
}
historyAction = false
switch v := next.(type) {
case rune:
switch v {
case cr, lf:
if s.multiLineMode {
s.resetMultiLine(p, line, pos)
}
fmt.Println()
break mainLoop
case ctrlA: // Start of line
pos = 0
s.refresh(p, line, pos)
case ctrlE: // End of line
pos = len(line)
s.refresh(p, line, pos)
case ctrlB: // left
if pos > 0 {
pos -= len(getSuffixGlyphs(line[:pos], 1))
s.refresh(p, line, pos)
} else {
fmt.Print(beep)
}
case ctrlF: // right
if pos < len(line) {
pos += len(getPrefixGlyphs(line[pos:], 1))
s.refresh(p, line, pos)
} else {
fmt.Print(beep)
}
case ctrlD: // del
if pos == 0 && len(line) == 0 {
// exit
return "", io.EOF
}
// ctrlD is a potential EOF, so the rune reader shuts down.
// Therefore, if it isn't actually an EOF, we must re-startPrompt.
s.restartPrompt()
if pos >= len(line) {
fmt.Print(beep)
} else {
n := len(getPrefixGlyphs(line[pos:], 1))
line = append(line[:pos], line[pos+n:]...)
s.refresh(p, line, pos)
}
case ctrlK: // delete remainder of line
if pos >= len(line) {
fmt.Print(beep)
} else {
if killAction > 0 {
s.addToKillRing(line[pos:], 1) // Add in apend mode
} else {
s.addToKillRing(line[pos:], 0) // Add in normal mode
}
killAction = 2 // Mark that there was a kill action
line = line[:pos]
s.refresh(p, line, pos)
}
case ctrlP: // up
historyAction = true
if historyPos > 0 {
if historyPos == len(prefixHistory) {
historyEnd = string(line)
}
historyPos--
line = []rune(prefixHistory[historyPos])
pos = len(line)
s.refresh(p, line, pos)
} else {
fmt.Print(beep)
}
case ctrlN: // down
historyAction = true
if historyPos < len(prefixHistory) {
historyPos++
if historyPos == len(prefixHistory) {
line = []rune(historyEnd)
} else {
line = []rune(prefixHistory[historyPos])
}
pos = len(line)
s.refresh(p, line, pos)
} else {
fmt.Print(beep)
}
case ctrlT: // transpose prev glyph with glyph under cursor
if len(line) < 2 || pos < 1 {
fmt.Print(beep)
} else {
if pos == len(line) {
pos -= len(getSuffixGlyphs(line, 1))
}
prev := getSuffixGlyphs(line[:pos], 1)
next := getPrefixGlyphs(line[pos:], 1)
scratch := make([]rune, len(prev))
copy(scratch, prev)
copy(line[pos-len(prev):], next)
copy(line[pos-len(prev)+len(next):], scratch)
pos += len(next)
s.refresh(p, line, pos)
}
case ctrlL: // clear screen
s.eraseScreen()
s.refresh(p, line, pos)
case ctrlC: // reset
fmt.Println("^C")
if s.multiLineMode {
s.resetMultiLine(p, line, pos)
}
if s.ctrlCAborts {
return "", ErrPromptAborted
}
line = line[:0]
pos = 0
fmt.Print(prompt)
s.restartPrompt()
case ctrlH, bs: // Backspace
if pos <= 0 {
fmt.Print(beep)
} else {
n := len(getSuffixGlyphs(line[:pos], 1))
line = append(line[:pos-n], line[pos:]...)
pos -= n
s.refresh(p, line, pos)
}
case ctrlU: // Erase line before cursor
if killAction > 0 {
s.addToKillRing(line[:pos], 2) // Add in prepend mode
} else {
s.addToKillRing(line[:pos], 0) // Add in normal mode
}
killAction = 2 // Mark that there was some killing
line = line[pos:]
pos = 0
s.refresh(p, line, pos)
case ctrlW: // Erase word
if pos == 0 {
fmt.Print(beep)
break
}
// Remove whitespace to the left
var buf []rune // Store the deleted chars in a buffer
for {
if pos == 0 || !unicode.IsSpace(line[pos-1]) {
break
}
buf = append(buf, line[pos-1])
line = append(line[:pos-1], line[pos:]...)
pos--
}
// Remove non-whitespace to the left
for {
if pos == 0 || unicode.IsSpace(line[pos-1]) {
break
}
buf = append(buf, line[pos-1])
line = append(line[:pos-1], line[pos:]...)
pos--
}
// Invert the buffer and save the result on the killRing
var newBuf []rune
for i := len(buf) - 1; i >= 0; i-- {
newBuf = append(newBuf, buf[i])
}
if killAction > 0 {
s.addToKillRing(newBuf, 2) // Add in prepend mode
} else {
s.addToKillRing(newBuf, 0) // Add in normal mode
}
killAction = 2 // Mark that there was some killing
s.refresh(p, line, pos)
case ctrlY: // Paste from Yank buffer
line, pos, next, err = s.yank(p, line, pos)
goto haveNext
case ctrlR: // Reverse Search
line, pos, next, err = s.reverseISearch(line, pos)
s.refresh(p, line, pos)
goto haveNext
case tab: // Tab completion
line, pos, next, err = s.tabComplete(p, line, pos)
goto haveNext
// Catch keys that do nothing, but you don't want them to beep
case esc:
// DO NOTHING
// Unused keys
case ctrlG, ctrlO, ctrlQ, ctrlS, ctrlV, ctrlX, ctrlZ:
fallthrough
// Catch unhandled control codes (anything <= 31)
case 0, 28, 29, 30, 31:
fmt.Print(beep)
default:
if pos == len(line) && !s.multiLineMode && countGlyphs(p)+countGlyphs(line) < s.columns-1 {
line = append(line, v)
fmt.Printf("%c", v)
pos++
} else {
line = append(line[:pos], append([]rune{v}, line[pos:]...)...)
pos++
s.refresh(p, line, pos)
}
}
case action:
switch v {
case del:
if pos >= len(line) {
fmt.Print(beep)
} else {
n := len(getPrefixGlyphs(line[pos:], 1))
line = append(line[:pos], line[pos+n:]...)
}
case left:
if pos > 0 {
pos -= len(getSuffixGlyphs(line[:pos], 1))
} else {
fmt.Print(beep)
}
case wordLeft, altB:
if pos > 0 {
var spaceHere, spaceLeft, leftKnown bool
for {
pos--
if pos == 0 {
break
}
if leftKnown {
spaceHere = spaceLeft
} else {
spaceHere = unicode.IsSpace(line[pos])
}
spaceLeft, leftKnown = unicode.IsSpace(line[pos-1]), true
if !spaceHere && spaceLeft {
break
}
}
} else {
fmt.Print(beep)
}
case right:
if pos < len(line) {
pos += len(getPrefixGlyphs(line[pos:], 1))
} else {
fmt.Print(beep)
}
case wordRight, altF:
if pos < len(line) {
var spaceHere, spaceLeft, hereKnown bool
for {
pos++
if pos == len(line) {
break
}
if hereKnown {
spaceLeft = spaceHere
} else {
spaceLeft = unicode.IsSpace(line[pos-1])
}
spaceHere, hereKnown = unicode.IsSpace(line[pos]), true
if spaceHere && !spaceLeft {
break
}
}
} else {
fmt.Print(beep)
}
case up:
historyAction = true
if historyPos > 0 {
if historyPos == len(prefixHistory) {
historyEnd = string(line)
}
historyPos--
line = []rune(prefixHistory[historyPos])
pos = len(line)
} else {
fmt.Print(beep)
}
case down:
historyAction = true
if historyPos < len(prefixHistory) {
historyPos++
if historyPos == len(prefixHistory) {
line = []rune(historyEnd)
} else {
line = []rune(prefixHistory[historyPos])
}
pos = len(line)
} else {
fmt.Print(beep)
}
case home: // Start of line
pos = 0
case end: // End of line
pos = len(line)
case winch: // Window change
if s.multiLineMode {
if s.maxRows-s.cursorRows > 0 {
s.moveDown(s.maxRows - s.cursorRows)
}
for i := 0; i < s.maxRows-1; i++ {
s.cursorPos(0)
s.eraseLine()
s.moveUp(1)
}
s.maxRows = 1
s.cursorRows = 1
}
}
s.refresh(p, line, pos)
}
if !historyAction {
prefixHistory = s.getHistoryByPrefix(string(line))
historyPos = len(prefixHistory)
}
if killAction > 0 {
killAction--
}
}
return string(line), nil
}
// PasswordPrompt displays p, and then waits for user input. The input typed by
// the user is not displayed in the terminal.
func (s *State) PasswordPrompt(prompt string) (string, error) {
if !s.terminalSupported {
return "", errors.New("liner: function not supported in this terminal")
}
if s.inputRedirected {
return s.promptUnsupported(prompt)
}
if s.outputRedirected {
return "", ErrNotTerminalOutput
}
defer s.stopPrompt()
restart:
s.startPrompt()
s.getColumns()
fmt.Print(prompt)
p := []rune(prompt)
var line []rune
pos := 0
mainLoop:
for {
next, err := s.readNext()
if err != nil {
if s.shouldRestart != nil && s.shouldRestart(err) {
goto restart
}
return "", err
}
switch v := next.(type) {
case rune:
switch v {
case cr, lf:
if s.multiLineMode {
s.resetMultiLine(p, line, pos)
}
fmt.Println()
break mainLoop
case ctrlD: // del
if pos == 0 && len(line) == 0 {
// exit
return "", io.EOF
}
// ctrlD is a potential EOF, so the rune reader shuts down.
// Therefore, if it isn't actually an EOF, we must re-startPrompt.
s.restartPrompt()
case ctrlL: // clear screen
s.eraseScreen()
s.refresh(p, []rune{}, 0)
case ctrlH, bs: // Backspace
if pos <= 0 {
fmt.Print(beep)
} else {
n := len(getSuffixGlyphs(line[:pos], 1))
line = append(line[:pos-n], line[pos:]...)
pos -= n
}
case ctrlC:
fmt.Println("^C")
if s.multiLineMode {
s.resetMultiLine(p, line, pos)
}
if s.ctrlCAborts {
return "", ErrPromptAborted
}
line = line[:0]
pos = 0
fmt.Print(prompt)
s.restartPrompt()
// Unused keys
case esc, tab, ctrlA, ctrlB, ctrlE, ctrlF, ctrlG, ctrlK, ctrlN, ctrlO, ctrlP, ctrlQ, ctrlR, ctrlS,
ctrlT, ctrlU, ctrlV, ctrlW, ctrlX, ctrlY, ctrlZ:
fallthrough
// Catch unhandled control codes (anything <= 31)
case 0, 28, 29, 30, 31:
fmt.Print(beep)
default:
line = append(line[:pos], append([]rune{v}, line[pos:]...)...)
pos++
}
}
}
return string(line), nil
}