From b16afaf79cbe934c7518c2fbf10fb18de0932834 Mon Sep 17 00:00:00 2001
From: Rafael Fourquet <fourquet.rafael@gmail.com>
Date: Mon, 4 Nov 2019 12:16:27 +0100
Subject: [PATCH] REPL: allow editing current input in editor (via Meta-e)

---
 stdlib/REPL/src/LineEdit.jl | 56 +++++++++++++++++++++++++++++++++++++
 stdlib/REPL/src/REPL.jl     | 11 ++------
 2 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/stdlib/REPL/src/LineEdit.jl b/stdlib/REPL/src/LineEdit.jl
index 89f57383d5e48..8d650815f31d6 100644
--- a/stdlib/REPL/src/LineEdit.jl
+++ b/stdlib/REPL/src/LineEdit.jl
@@ -12,6 +12,8 @@ import ..Terminals: raw!, width, height, cmove, getX,
 import Base: ensureroom, show, AnyDict, position
 using Base: something
 
+using InteractiveUtils: InteractiveUtils
+
 abstract type TextInterface end                # see interface immediately below
 abstract type ModeState end                    # see interface below
 abstract type HistoryProvider end
@@ -1295,6 +1297,59 @@ _edit_indent(buf::IOBuffer, b::Int, num::Int) =
     num >= 0 ? edit_splice!(buf, b => b, ' '^num, rigid_mark=false) :
                edit_splice!(buf, b => (b - num))
 
+function mode_idx(hist #=::REPLHistoryProvider =#, mode::TextInterface)
+    c = :julia
+    for (k,v) in hist.mode_mapping
+        isequal(v, mode) && (c = k)
+    end
+    return c
+end
+
+function guess_current_mode_name(s)
+    try
+        mode_idx(s.current_mode.hist, s.current_mode)
+    catch
+        nothing
+    end
+end
+
+# edit current input in editor
+function edit_input(s)
+    mode_name = guess_current_mode_name(s)
+    filename = tempname()
+    if mode_name == :julia
+        filename *= ".jl"
+    elseif mode_name == :shell
+        filename *= ".sh"
+    end
+    buf = buffer(s)
+    data = buf.data
+    pos = position(buf)
+    size0 = buf.size
+    resize!(data, buf.size) # to not write garbage into filename
+    line = 1 + count(==(_newline), view(data, 1:pos))
+    ct0 = open(filename, "w") do io
+        write(io, data)
+        ctime(io)
+    end
+    InteractiveUtils.edit(filename, line)
+    n, ct = open(filename) do io
+        readbytes!(io, empty!(buf.data), typemax(Int)),
+        ctime(io)
+    end
+    rm(filename)
+    @assert n == length(buf.data)
+    buf.size = n
+    buf.ptr = n+1
+    if ct0 != ct # something was changed, run the input
+        commit_line(s)
+        :done
+    else # no change, the edit session probably unsuccessful
+        @assert n == size0
+        seek(buf, pos) # restore state from before edit
+        refresh_line(s)
+    end
+end
 
 history_prev(::EmptyHistoryProvider) = ("", false)
 history_next(::EmptyHistoryProvider) = ("", false)
@@ -2337,6 +2392,7 @@ AnyDict(
     "\eu" => (s::MIState,o...)->edit_upper_case(s),
     "\el" => (s::MIState,o...)->edit_lower_case(s),
     "\ec" => (s::MIState,o...)->edit_title_case(s),
+    "\ee" => (s::MIState,o...) -> edit_input(s),
 )
 
 const history_keymap = AnyDict(
diff --git a/stdlib/REPL/src/REPL.jl b/stdlib/REPL/src/REPL.jl
index bf3345f158168..5ff5e70e588ba 100644
--- a/stdlib/REPL/src/REPL.jl
+++ b/stdlib/REPL/src/REPL.jl
@@ -59,7 +59,8 @@ import ..LineEdit:
     terminal,
     MIState,
     PromptState,
-    TextInterface
+    TextInterface,
+    mode_idx
 
 include("REPLCompletions.jl")
 using .REPLCompletions
@@ -601,14 +602,6 @@ function hist_from_file(hp::REPLHistoryProvider, path::String)
     return hp
 end
 
-function mode_idx(hist::REPLHistoryProvider, mode::TextInterface)
-    c = :julia
-    for (k,v) in hist.mode_mapping
-        isequal(v, mode) && (c = k)
-    end
-    return c
-end
-
 function add_history(hist::REPLHistoryProvider, s::PromptState)
     str = rstrip(String(take!(copy(s.input_buffer))))
     isempty(strip(str)) && return