Add block_keyword_or_binary_operator to Code.Fragment (#14414)

Author: josevalim

lib/elixir/lib/code/fragment.ex

@@ -46,6 +46,9 @@ defmodule Code.Fragment do
       or `{:local_or_var, charlist}` and `charlist` is a static part
       Examples are `__MODULE__.Submodule` or `@hello.Submodule`
 
+    * `{:block_keyword_or_binary_operator, charlist}` - may be a block keyword (do, end, after,
+      catch, else, rescue) or a binary operator
+
     * `{:dot, inside_dot, charlist}` - the context is a dot
       where `inside_dot` is either a `{:var, charlist}`, `{:alias, charlist}`,
       `{:module_attribute, charlist}`, `{:unquoted_atom, charlist}` or a `dot`
@@ -139,6 +142,7 @@ defmodule Code.Fragment do
   @spec cursor_context(List.Chars.t(), keyword()) ::
           {:alias, charlist}
           | {:alias, inside_alias, charlist}
+          | {:block_keyword_or_binary_operator, charlist}
           | {:dot, inside_dot, charlist}
           | {:dot_arity, inside_dot, charlist}
           | {:dot_call, inside_dot, charlist}
@@ -188,15 +192,15 @@ defmodule Code.Fragment do
     cursor_context(to_charlist(other), opts)
   end
 
-  @operators ~c"\\<>+-*/:=|&~^%!"
-  @starter_punctuation ~c",([{;"
-  @non_starter_punctuation ~c")]}\"'.$"
+  @operators ~c"\\<>+-*/:=|&~^%!$"
+  @starting_punctuation ~c",([{;"
+  @closing_punctuation ~c")]}\"'"
   @space ~c"\t\s"
   @trailing_identifier ~c"?!"
   @tilde_op_prefix ~c"<=~"
 
   @non_identifier @trailing_identifier ++
-                    @operators ++ @starter_punctuation ++ @non_starter_punctuation ++ @space
+                    @operators ++ @starting_punctuation ++ @closing_punctuation ++ @space ++ [?.]
 
   @textual_operators ~w(when not and or in)c
   @keywords ~w(do end after else catch rescue fn true false nil)c
@@ -226,11 +230,11 @@ defmodule Code.Fragment do
       # A local arity definition
       [?/ | rest] -> arity_to_cursor_context(strip_spaces(rest, spaces + 1))
       # Starting a new expression
-      [h | _] when h in @starter_punctuation -> {:expr, 0}
-      # It is a local or remote call without parens
-      rest when spaces > 0 -> call_to_cursor_context({rest, spaces})
+      [h | _] when h in @starting_punctuation -> {:expr, 0}
+      # It is keyword, binary operator, a local or remote call without parens
+      rest when spaces > 0 -> closing_or_call_to_cursor_context({rest, spaces})
       # It is an identifier
-      _ -> identifier_to_cursor_context(reverse, 0, false)
+      _ -> identifier_to_cursor_context(reverse, spaces, false)
     end
   end
 
@@ -269,6 +273,14 @@ defmodule Code.Fragment do
     end
   end
 
+  defp closing_or_call_to_cursor_context({reverse, spaces}) do
+    if closing?(reverse) do
+      {{:block_keyword_or_binary_operator, ~c""}, 0}
+    else
+      call_to_cursor_context({reverse, spaces})
+    end
+  end
+
   defp identifier_to_cursor_context([?., ?., ?: | _], n, _), do: {{:unquoted_atom, ~c".."}, n + 3}
   defp identifier_to_cursor_context([?., ?., ?. | _], n, _), do: {{:local_or_var, ~c"..."}, n + 3}
   defp identifier_to_cursor_context([?., ?: | _], n, _), do: {{:unquoted_atom, ~c"."}, n + 2}
@@ -320,15 +332,42 @@ defmodule Code.Fragment do
           {~c"." ++ rest, count} when rest == [] or hd(rest) != ?. ->
             dot(rest, count + 1, acc)
 
-          _ ->
-            {{:local_or_var, acc}, count}
+          {rest, rest_count} ->
+            response =
+              if rest_count > count and closing?(rest),
+                do: :block_keyword_or_binary_operator,
+                else: :local_or_var
+
+            {{response, acc}, count}
         end
 
       {:capture_arg, acc, count} ->
         {{:capture_arg, acc}, count}
     end
   end
 
+  # If it is a closing punctuation
+  defp closing?([h | _]) when h in @closing_punctuation, do: true
+  # Closing bitstring (but deal with operators)
+  defp closing?([?>, ?> | rest]), do: rest == [] or hd(rest) not in [?>, ?~]
+  # Keywords
+  defp closing?(rest) do
+    case split_non_identifier(rest, []) do
+      {~c"nil", _} -> true
+      {~c"true", _} -> true
+      {~c"false", _} -> true
+      {[digit | _], _} when digit in ?0..?9 -> true
+      {[upper | _], _} when upper in ?A..?Z -> true
+      {[_ | _], [?: | rest]} -> rest == [] or hd(rest) != ?:
+      {_, _} -> false
+    end
+  end
+
+  defp split_non_identifier([h | t], acc) when h not in @non_identifier,
+    do: split_non_identifier(t, [h | acc])
+
+  defp split_non_identifier(rest, acc), do: {acc, rest}
+
   defp identifier([?? | rest], count), do: check_identifier(rest, count + 1, [??])
   defp identifier([?! | rest], count), do: check_identifier(rest, count + 1, [?!])
   defp identifier(rest, count), do: check_identifier(rest, count, [])

lib/elixir/test/elixir/code_fragment_test.exs

@@ -240,6 +240,9 @@ defmodule CodeFragmentTest do
       assert CF.cursor_context("Hello::Wor") == {:alias, ~c"Wor"}
       assert CF.cursor_context("Hello..Wor") == {:alias, ~c"Wor"}
 
+      assert CF.cursor_context("hello.World") ==
+               {:alias, {:local_or_var, ~c"hello"}, ~c"World"}
+
       assert CF.cursor_context("__MODULE__.Wor") ==
                {:alias, {:local_or_var, ~c"__MODULE__"}, ~c"Wor"}
 
@@ -368,6 +371,76 @@ defmodule CodeFragmentTest do
       assert CF.cursor_context("@hello_wo") == {:module_attribute, ~c"hello_wo"}
     end
 
+    test "keyword or binary operator" do
+      # Literals
+      assert CF.cursor_context("Foo.Bar ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("Foo ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context(":foo ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("123 ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("nil ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("true ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("false ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("\"foo\" ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("'foo' ") == {:block_keyword_or_binary_operator, ~c""}
+
+      # Containers
+      assert CF.cursor_context("(foo) ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("[foo] ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("{foo} ") == {:block_keyword_or_binary_operator, ~c""}
+      assert CF.cursor_context("<<foo>> ") == {:block_keyword_or_binary_operator, ~c""}
+
+      # False positives
+      assert CF.cursor_context("foo ~>> ") == {:operator_call, ~c"~>>"}
+      assert CF.cursor_context("foo >>> ") == {:operator_call, ~c">>>"}
+    end
+
+    test "keyword from keyword or binary operator" do
+      # Literals
+      assert CF.cursor_context("Foo.Bar do") == {:block_keyword_or_binary_operator, ~c"do"}
+      assert CF.cursor_context("Foo.Bar d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("Foo d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context(":foo d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("123 d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("nil d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("true d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("false d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("\"foo\" d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("'foo' d") == {:block_keyword_or_binary_operator, ~c"d"}
+
+      # Containers
+      assert CF.cursor_context("(foo) d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("[foo] d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("{foo} d") == {:block_keyword_or_binary_operator, ~c"d"}
+      assert CF.cursor_context("<<foo>> d") == {:block_keyword_or_binary_operator, ~c"d"}
+
+      # False positives
+      assert CF.cursor_context("foo ~>> d") == {:local_or_var, ~c"d"}
+      assert CF.cursor_context("foo >>> d") == {:local_or_var, ~c"d"}
+    end
+
+    test "operator from keyword or binary operator" do
+      # Literals
+      assert CF.cursor_context("Foo.Bar +") == {:operator, ~c"+"}
+      assert CF.cursor_context("Foo +") == {:operator, ~c"+"}
+      assert CF.cursor_context(":foo +") == {:operator, ~c"+"}
+      assert CF.cursor_context("123 +") == {:operator, ~c"+"}
+      assert CF.cursor_context("nil +") == {:operator, ~c"+"}
+      assert CF.cursor_context("true +") == {:operator, ~c"+"}
+      assert CF.cursor_context("false +") == {:operator, ~c"+"}
+      assert CF.cursor_context("\"foo\" +") == {:operator, ~c"+"}
+      assert CF.cursor_context("'foo' +") == {:operator, ~c"+"}
+
+      # Containers
+      assert CF.cursor_context("(foo) +") == {:operator, ~c"+"}
+      assert CF.cursor_context("[foo] +") == {:operator, ~c"+"}
+      assert CF.cursor_context("{foo} +") == {:operator, ~c"+"}
+      assert CF.cursor_context("<<foo>> +") == {:operator, ~c"+"}
+
+      # False positives
+      assert CF.cursor_context("foo ~>> +") == {:operator, ~c"+"}
+      assert CF.cursor_context("foo >>> +") == {:operator, ~c"+"}
+    end
+
     test "none" do
       # Punctuation
       assert CF.cursor_context(")") == :none
@@ -399,8 +472,6 @@ defmodule CodeFragmentTest do
       assert CF.cursor_context("HelloWór") == :none
       assert CF.cursor_context("@Hello") == :none
       assert CF.cursor_context("Hello(") == :none
-      assert CF.cursor_context("Hello ") == :none
-      assert CF.cursor_context("hello.World") == {:alias, {:local_or_var, ~c"hello"}, ~c"World"}
 
       # Identifier
       assert CF.cursor_context("foo@bar") == :none

lib/iex/lib/iex/autocomplete.ex

@@ -22,6 +22,23 @@ defmodule IEx.Autocomplete do
     %{kind: :variable, name: "utf32"}
   ]
 
+  block_keywords =
+    for block_keyword <- ~w(do end after catch else rescue) do
+      %{kind: :block_keyword, name: block_keyword}
+    end
+
+  binary_operators =
+    for operator <-
+          ["**", "*", "/", "+", "-", "++", "--", "+++", "---", "..", "<>"] ++
+            ["in", "not in", "|>", "<<<", ">>>", "<<~", "~>>", "<~", "~>", "<~>"] ++
+            ["<", ">", "<=", ">=", "==", "!=", "=~", "===", "!=="] ++
+            ["&&", "&&&", "and", "||", "|||", "or"] ++
+            ["=", "=>", "|", "::", "when", "<-", "\\\\"] do
+      %{kind: :export, name: operator, arity: 2}
+    end
+
+  @block_keyword_or_binary_operator block_keywords ++ Enum.sort(binary_operators)
+
   @alias_only_atoms ~w(alias import require)a
   @alias_only_charlists ~w(alias import require)c
 
@@ -63,6 +80,9 @@ defmodule IEx.Autocomplete do
       {:unquoted_atom, unquoted_atom} ->
         expand_erlang_modules(List.to_string(unquoted_atom))
 
+      {:block_keyword_or_binary_operator, hint} ->
+        filter_and_format_expansion(@block_keyword_or_binary_operator, List.to_string(hint))
+
       expansion when helper == ?b ->
         expand_typespecs(expansion, shell, &get_module_callbacks/1)
 
@@ -519,6 +539,12 @@ defmodule IEx.Autocomplete do
 
   ## Formatting
 
+  defp filter_and_format_expansion(results, hint) do
+    results
+    |> Enum.filter(&String.starts_with?(&1.name, hint))
+    |> format_expansion(hint)
+  end
+
   defp format_expansion([], _) do
     no()
   end

lib/iex/test/iex/autocomplete_test.exs

@@ -184,6 +184,21 @@ defmodule IEx.AutocompleteTest do
     assert expand(~c"IEx.Xyz") == {:no, ~c"", []}
   end
 
+  test "block keywords" do
+    assert expand(~c"if true do") == {:yes, ~c"", [~c"do"]}
+    assert expand(~c"if true a") == {:yes, ~c"", [~c"after", ~c"and/2"]}
+    assert expand(~c"if true d") == {:yes, ~c"o", []}
+    assert expand(~c"if true e") == {:yes, ~c"", [~c"end", ~c"else"]}
+  end
+
+  test "block keywords or operators" do
+    {:yes, ~c"", hints} = expand(~c"if true ")
+    assert ~c"do" in hints
+    assert ~c"else" in hints
+    assert ~c"+/2" in hints
+    assert ~c"and/2" in hints
+  end
+
   test "function completion" do
     assert expand(~c"System.ve") == {:yes, ~c"rsion", []}
     assert expand(~c":ets.fun2") == {:yes, ~c"ms", []}