REPL: implement "insert last word from previous history entry"

Bind this shell-like feature to the usual "meta-.".
JuliaLang · Nov 4, 2019 · d9a4873 · d9a4873
1 parent ffdee15
commit d9a4873
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diff --git a/stdlib/REPL/docs/src/index.md b/stdlib/REPL/docs/src/index.md
@@ -174,6 +174,7 @@ to do so), or pressing Esc and then the key.
 | `^Q`                | Write a number in REPL and press `^Q` to open editor at corresponding stackframe or method                 |
 | `meta-Left Arrow`   | indent the current line on the left                                                                        |
 | `meta-Right Arrow`  | indent the current line on the right                                                                       |
+| `meta-.`            | insert last word from previous history entry                                                               |
 
 
 ### Customizing keybindings

diff --git a/stdlib/REPL/src/LineEdit.jl b/stdlib/REPL/src/LineEdit.jl
@@ -1942,6 +1942,25 @@ function move_line_end(buf::IOBuffer)
     nothing
 end
 
+edit_insert_last_word(s::MIState) =
+    edit_insert(s, get_last_word(IOBuffer(mode(s).hist.history[end])))
+
+function get_last_word(buf::IOBuffer)
+    move_line_end(buf)
+    char_move_word_left(buf)
+    posbeg = position(buf)
+    char_move_word_right(buf)
+    posend = position(buf)
+    buf = take!(buf)
+    word = String(buf[posbeg+1:posend])
+    rest = String(buf[posend+1:end])
+    lp, rp, lb, rb = count.(.==(('(', ')', '[', ']')), rest)
+    special = any(in.(('\'', '"', '`'), rest))
+    !special && lp == rp && lb == rb ?
+        word *= rest :
+        word
+end
+
 function commit_line(s)
     cancel_beep(s)
     move_input_end(s)
@@ -2080,6 +2099,7 @@ AnyDict(
     "\eOc" => "\ef",
     # Meta Enter
     "\e\r" => (s,o...)->edit_insert_newline(s),
+    "\e." =>  (s,o...)->edit_insert_last_word(s),
     "\e\n" => "\e\r",
     "^_" => (s,o...)->edit_undo!(s),
     "\e_" => (s,o...)->edit_redo!(s),

diff --git a/stdlib/REPL/test/lineedit.jl b/stdlib/REPL/test/lineedit.jl
@@ -878,5 +878,20 @@ end
     buf.mark = 0
     seek(buf, 1)
     @test transform!(transpose_lines_down_reg!, buf) == ("l2\nl3\nl1", 4, 3)
+end
 
+@testset "edit_insert_last_word" begin
+    get_last_word(str::String) = LineEdit.get_last_word(IOBuffer(str))
+    @test get_last_word("1+2") == "2"
+    @test get_last_word("1+23") == "23"
+    @test get_last_word("1+2") == "2"
+    @test get_last_word(""" "a" * "b" """) == "b"
+    @test get_last_word(""" "a" * 'b' """) == "b"
+    @test get_last_word(""" "a" * `b` """) == "b"
+    @test get_last_word("g()") == "g()"
+    @test get_last_word("g(1, 2)") == "2"
+    @test get_last_word("g(1, f())") == "f"
+    @test get_last_word("a[1]") == "1"
+    @test get_last_word("a[b[]]") == "b"
+    @test get_last_word("a[]") == "a[]"
 end
diff --git a/stdlib/REPL/test/repl.jl b/stdlib/REPL/test/repl.jl
@@ -415,6 +415,11 @@ for prompt = ["TestΠ", () -> randstring(rand(1:10))]
         s = LineEdit.init_state(repl.t, repl.interface)
         LineEdit.edit_insert(s, "wip")
 
+        # LineEdit functions related to history
+        LineEdit.edit_insert_last_word(s)
+        @test buffercontents(LineEdit.buffer(s)) == "wip2"
+        LineEdit.edit_backspace(s) # remove the "2"
+
         # Test that navigating history skips invalid modes
         # (in both directions)
         LineEdit.history_prev(s, hp)