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package dotty.tools
package dotc
package repl
package ammonite
package terminal
package filters
import terminal.FilterTools._
import terminal.SpecialKeys._
import terminal.{DelegateFilter, Filter, Terminal}
/**
* Filters for injection of readline-specific hotkeys, the sort that
* are available in bash, python and most other interactive command-lines
*/
object ReadlineFilters {
// www.bigsmoke.us/readline/shortcuts
// Ctrl-b <- one char
// Ctrl-f -> one char
// Alt-b <- one word
// Alt-f -> one word
// Ctrl-a <- start of line
// Ctrl-e -> end of line
// Ctrl-x-x Toggle start/end
// Backspace <- delete char
// Del -> delete char
// Ctrl-u <- delete all
// Ctrl-k -> delete all
// Alt-d -> delete word
// Ctrl-w <- delete word
// Ctrl-u/- Undo
// Ctrl-l clear screen
// Ctrl-k -> cut all
// Alt-d -> cut word
// Alt-Backspace <- cut word
// Ctrl-y paste last cut
/**
* Basic readline-style navigation, using all the obscure alphabet hotkeys
* rather than using arrows
*/
lazy val navFilter = Filter.merge(
Case(Ctrl('b'))((b, c, m) => (b, c - 1)), // <- one char
Case(Ctrl('f'))((b, c, m) => (b, c + 1)), // -> one char
Case(Alt + "b")((b, c, m) => GUILikeFilters.wordLeft(b, c)), // <- one word
Case(Alt + "B")((b, c, m) => GUILikeFilters.wordLeft(b, c)), // <- one word
Case(LinuxCtrlLeft)((b, c, m) => GUILikeFilters.wordLeft(b, c)), // <- one word
Case(Alt + "f")((b, c, m) => GUILikeFilters.wordRight(b, c)), // -> one word
Case(Alt + "F")((b, c, m) => GUILikeFilters.wordRight(b, c)), // -> one word
Case(LinuxCtrlRight)((b, c, m) => GUILikeFilters.wordRight(b, c)), // -> one word
Case(Home)((b, c, m) => BasicFilters.moveStart(b, c, m.width)), // <- one line
Case(HomeScreen)((b, c, m) => BasicFilters.moveStart(b, c, m.width)), // <- one line
Case(Ctrl('a'))((b, c, m) => BasicFilters.moveStart(b, c, m.width)),
Case(End)((b, c, m) => BasicFilters.moveEnd(b, c, m.width)), // -> one line
Case(EndScreen)((b, c, m) => BasicFilters.moveEnd(b, c, m.width)), // -> one line
Case(Ctrl('e'))((b, c, m) => BasicFilters.moveEnd(b, c, m.width)),
Case(Alt + "t")((b, c, m) => transposeWord(b, c)),
Case(Alt + "T")((b, c, m) => transposeWord(b, c)),
Case(Ctrl('t'))((b, c, m) => transposeLetter(b, c))
)
def transposeLetter(b: Vector[Char], c: Int) =
// If there's no letter before the cursor to transpose, don't do anything
if (c == 0) (b, c)
else if (c == b.length) (b.dropRight(2) ++ b.takeRight(2).reverse, c)
else (b.patch(c-1, b.slice(c-1, c+1).reverse, 2), c + 1)
def transposeWord(b: Vector[Char], c: Int) = {
val leftStart0 = GUILikeFilters.consumeWord(b, c - 1, -1, 1)
val leftEnd0 = GUILikeFilters.consumeWord(b, leftStart0, 1, 0)
val rightEnd = GUILikeFilters.consumeWord(b, c, 1, 0)
val rightStart = GUILikeFilters.consumeWord(b, rightEnd - 1, -1, 1)
// If no word to the left to transpose, do nothing
if (leftStart0 == 0 && rightStart == 0) (b, c)
else {
val (leftStart, leftEnd) =
// If there is no word to the *right* to transpose,
// transpose the two words to the left instead
if (leftEnd0 == b.length && rightEnd == b.length) {
val leftStart = GUILikeFilters.consumeWord(b, leftStart0 - 1, -1, 1)
val leftEnd = GUILikeFilters.consumeWord(b, leftStart, 1, 0)
(leftStart, leftEnd)
}else (leftStart0, leftEnd0)
val newB =
b.slice(0, leftStart) ++
b.slice(rightStart, rightEnd) ++
b.slice(leftEnd, rightStart) ++
b.slice(leftStart, leftEnd) ++
b.slice(rightEnd, b.length)
(newB, rightEnd)
}
}
/**
* All the cut-pasting logic, though for many people they simply
* use these shortcuts for deleting and don't use paste much at all.
*/
case class CutPasteFilter() extends DelegateFilter {
def identifier = "CutPasteFilter"
var accumulating = false
var currentCut = Vector.empty[Char]
def prepend(b: Vector[Char]) = {
if (accumulating) currentCut = b ++ currentCut
else currentCut = b
accumulating = true
}
def append(b: Vector[Char]) = {
if (accumulating) currentCut = currentCut ++ b
else currentCut = b
accumulating = true
}
def cutCharLeft(b: Vector[Char], c: Int) = {
/* Do not edit current cut. Zsh(zle) & Bash(readline) do not edit the yank ring for Ctrl-h */
(b patch(from = c - 1, patch = Nil, replaced = 1), c - 1)
}
def cutAllLeft(b: Vector[Char], c: Int) = {
prepend(b.take(c))
(b.drop(c), 0)
}
def cutAllRight(b: Vector[Char], c: Int) = {
append(b.drop(c))
(b.take(c), c)
}
def cutWordRight(b: Vector[Char], c: Int) = {
val start = GUILikeFilters.consumeWord(b, c, 1, 0)
append(b.slice(c, start))
(b.take(c) ++ b.drop(start), c)
}
def cutWordLeft(b: Vector[Char], c: Int) = {
val start = GUILikeFilters.consumeWord(b, c - 1, -1, 1)
prepend(b.slice(start, c))
(b.take(start) ++ b.drop(c), start)
}
def paste(b: Vector[Char], c: Int) = {
accumulating = false
(b.take(c) ++ currentCut ++ b.drop(c), c + currentCut.length)
}
def filter = Filter.merge(
Case(Ctrl('u'))((b, c, m) => cutAllLeft(b, c)),
Case(Ctrl('k'))((b, c, m) => cutAllRight(b, c)),
Case(Alt + "d")((b, c, m) => cutWordRight(b, c)),
Case(Ctrl('w'))((b, c, m) => cutWordLeft(b, c)),
Case(Alt + "\u007f")((b, c, m) => cutWordLeft(b, c)),
// weird hacks to make it run code every time without having to be the one
// handling the input; ideally we'd change Filter to be something
// other than a PartialFunction, but for now this will do.
// If some command goes through that's not appending/prepending to the
// kill ring, stop appending and allow the next kill to override it
Filter.wrap("ReadLineFilterWrap") {_ => accumulating = false; None},
Case(Ctrl('h'))((b, c, m) => cutCharLeft(b, c)),
Case(Ctrl('y'))((b, c, m) => paste(b, c))
)
}
}
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