REPL: add few "region" operations

* add possibility to set the "mark" in the edit area, with C-Space
* the mark and current position (the "point") delimit a region
* C-x C-x exchanges the mark with the point
* M-w is set to copy the region into the kill buffer
* M-W is set to kill the region into the kill buffer
  (in Emacs, the binding for this is C-w, but it's already taken
  by edit_werase)

base/repl/LineEdit.jl

@@ -67,6 +67,19 @@ mutable struct PromptState <: ModeState
  indent::Int
 end
 
+setmark(s) = mark(buffer(s))
+
+# the default mark is 0
+getmark(s) = max(0, buffer(s).mark)
+
+# given two buffer positions delimitating a region
+# as an close-open range, return a range of the included
+# positions, 0-based (suitable for splice_buffer!)
+region(a::Int, b::Int) = ((a, b) = minmax(a, b); a:b-1)
+region(s) = region(getmark(s), position(buffer(s)))
+
+const REGION_ANIMATION_DURATION = Ref(.2)
+
 input_string(s::PromptState) = String(take!(copy(s.input_buffer)))
 
 input_string_newlines(s::PromptState) = count(c->(c == '\n'), input_string(s))
@@ -286,6 +299,18 @@ function reset_key_repeats(f::Function, s::MIState)
  end
 end
 
+edit_exchange_point_and_mark(s::MIState) =
+ edit_exchange_point_and_mark(buffer(s)) && (refresh_line(s); true)
+
+function edit_exchange_point_and_mark(buf::IOBuffer)
+ m = getmark(buf)
+ p = position(buf)
+ m == p && return false
+ mark(buf)
+ seek(buf, m)
+ true
+end
+
 char_move_left(s::PromptState) = char_move_left(s.input_buffer)
 function char_move_left(buf::IOBuffer)
  while position(buf) > 0
@@ -430,16 +455,23 @@ end
 
 # splice! for IOBuffer: convert from 0-indexed positions, update the size,
 # and keep the cursor position stable with the text
+# returns the removed portion as a String
 function splice_buffer!(buf::IOBuffer, r::UnitRange{<:Integer}, ins::AbstractString = "")
  pos = position(buf)
- if !isempty(r) && pos in r
+ if pos in r
  seek(buf, first(r))
  elseif pos > last(r)
  seek(buf, pos - length(r))
  end
- splice!(buf.data, r + 1, Vector{UInt8}(ins)) # position(), etc, are 0-indexed
+ if first(r) < buf.mark <= last(r)
+ unmark(buf)
+ elseif buf.mark > last(r) && !isempty(r)
+ buf.mark += sizeof(ins) - length(r)
+ end
+ ret = splice!(buf.data, r + 1, Vector{UInt8}(ins)) # position(), etc, are 0-indexed
  buf.size = buf.size + sizeof(ins) - length(r)
  seek(buf, position(buf) + sizeof(ins))
+ String(ret)
 end
 
 function edit_replace(s, from, to, str)
@@ -587,7 +619,28 @@ function edit_kill_line(s::MIState)
  refresh_line(s)
 end
 
+function edit_copy_region(s::MIState)
+ buf = buffer(s)
+ if edit_exchange_point_and_mark(buf) # region non-empty
+ s.kill_buffer = String(buf.data[region(buf)+1])
+ if REGION_ANIMATION_DURATION[] > 0.0
+ refresh_line(s)
+ sleep(REGION_ANIMATION_DURATION[])
+ end
+ edit_exchange_point_and_mark(s) # includes refresh_line
+ end
+end
+
+function edit_kill_region(s::MIState)
+ reg = region(s)
+ if !isempty(reg)
+ s.kill_buffer = splice_buffer!(buffer(s), reg)
+ refresh_line(s)
+ end
+end
+
 edit_transpose(s) = edit_transpose(buffer(s)) && refresh_line(s)
+
 function edit_transpose(buf::IOBuffer)
  position(buf) == 0 && return false
  eof(buf) && char_move_left(buf)
@@ -728,20 +781,14 @@ function add_nested_key!(keymap::Dict, key, value; override = false)
  i = start(key)
  while !done(key, i)
  c, i = next(key, i)
- if c in keys(keymap)
- if done(key, i) && override
- # isa(keymap[c], Dict) - In this case we're overriding a prefix of an existing command
- keymap[c] = value
- break
- else
- if !isa(keymap[c], Dict)
- error("Conflicting definitions for keyseq " * escape_string(key) * " within one keymap")
- end
- end
- elseif done(key, i)
+ if !override && c in keys(keymap) && (done(key, i) || !isa(keymap[c], Dict))
+ error("Conflicting definitions for keyseq " * escape_string(key) *
+ " within one keymap")
+ end
+ if done(key, i)
  keymap[c] = value
  break
- else
+ elseif !(c in keys(keymap) && isa(keymap[c], Dict))
  keymap[c] = Dict{Char,Any}()
  end
  keymap = keymap[c]
@@ -1443,6 +1490,9 @@ AnyDict(
  return :abort
  end
  end,
+ # Ctrl-Space
+ "\0" => (s,o...)->setmark(s),
+ "^X^X" => (s,o...)->edit_exchange_point_and_mark(s),
  "^B" => (s,o...)->edit_move_left(s),
  "^F" => (s,o...)->edit_move_right(s),
  # Meta B
@@ -1465,6 +1515,8 @@ AnyDict(
  "^U" => (s,o...)->edit_clear(s),
  "^K" => (s,o...)->edit_kill_line(s),
  "^Y" => (s,o...)->edit_yank(s),
+ "\ew" => (s,o...)->edit_copy_region(s),
+ "\eW" => (s,o...)->edit_kill_region(s),
  "^A" => (s,o...)->(move_line_start(s); refresh_line(s)),
  "^E" => (s,o...)->(move_line_end(s); refresh_line(s)),
  # Try to catch all Home/End keys
@@ -1665,6 +1717,7 @@ end
 buffer(s::PromptState) = s.input_buffer
 buffer(s::SearchState) = s.query_buffer
 buffer(s::PrefixSearchState) = s.response_buffer
+buffer(s::IOBuffer) = s
 
 keymap(s::PromptState, prompt::Prompt) = prompt.keymap_dict
 keymap_data(s::PromptState, prompt::Prompt) = prompt.keymap_func_data

doc/src/manual/interacting-with-julia.md

@@ -160,17 +160,19 @@ to do so).
 | Down arrow | Move down one line (or to the next history entry) |
 | Page-up | Change to the previous history entry that matches the text before the cursor |
 | Page-down | Change to the next history entry that matches the text before the cursor |
-| `meta-F` | Move right one word |
-| `meta-B` | Move left one word |
+| `meta-f` | Move right one word |
+| `meta-b` | Move left one word |
 | `meta-<` | Change to the first history entry (of the current session if it is before the current position in history) |
 | `meta->` | Change to the last history entry |
 | **Editing** |   |
 | Backspace, `^H` | Delete the previous character |
 | Delete, `^D` | Forward delete one character (when buffer has text) |
 | meta-Backspace | Delete the previous word |
-| `meta-D` | Forward delete the next word |
+| `meta-d` | Forward delete the next word |
 | `^W` | Delete previous text up to the nearest whitespace |
-| `^K` | "Kill" to end of line, placing the text in a buffer |
+| `meta-w` | Copy the current region in the kill buffer |
+| `meta-W` | "Kill" the current region, placed the text in the kill buffer |
+| `^K` | "Kill" to end of line, placing the text in the kill buffer |
 | `^Y` | "Yank" insert the text from the kill buffer |
 | `^T` | Transpose the characters about the cursor |
 | `^Q` | Write a number in REPL and press `^Q` to open editor at corresponding stackframe or method |