Shell: expand 0-arity functions all the way to closing parenthesis

`erl` has tab completion for modules' exported functions but expands
only up to the opening paren. This commit closes that opening paren
in case the function is of arity zero and there is no other function with
the same name. It browses the lists of matches (a 2nd time) for Arity,
on complete match and then decides what to append.

4 files changed, 21 insertions, 8 deletions

diff --git a/lib/stdlib/src/edlin_expand.erl b/lib/stdlib/src/edlin_expand.erl
index 516c0aa30b..0033010dce 100644
--- a/lib/stdlib/src/edlin_expand.erl
+++ b/lib/stdlib/src/edlin_expand.erl
@@ -89,7 +89,13 @@ match(Prefix, Alts, Extra) ->
  		    {yes, Remain, []}
  	    end;
  	{complete, Str} ->
- 	    {yes, nthtail(Len, Str) ++ Extra, []};
+            {_, Arity} = lists:keyfind(Str, 1, Matches),
+            case {Arity, Extra} of
+                {0, "("} ->
+                    {yes, nthtail(Len, Str) ++ "()", []};
+                _ ->
+                    {yes, nthtail(Len, Str) ++ Extra, []}
+            end;
  	no ->
  	    {no, [], []}
     end.
diff --git a/lib/stdlib/test/edlin_expand_SUITE.erl b/lib/stdlib/test/edlin_expand_SUITE.erl
index 0cd2688e2e..2c1c5acf5a 100644
--- a/lib/stdlib/test/edlin_expand_SUITE.erl
+++ b/lib/stdlib/test/edlin_expand_SUITE.erl
@@ -76,11 +76,14 @@ normal(Config) when is_list(Config) ->
 	   [{"a_fun_name",1},
 	    {"a_less_fun_name",1},
 	    {"b_comes_after_a",1},
+            {"expand0arity_entirely",0},
 	    {"module_info",0},
 	    {"module_info",1}]} = edlin_expand:expand(lists:reverse("expand_test:")),
     ?line {yes,[],[{"a_fun_name",1},
 		   {"a_less_fun_name",1}]} = edlin_expand:expand(
 					       lists:reverse("expand_test:a_")),
+    ?line {yes,"arity_entirely()",[]} = edlin_expand:expand(
+                                         lists:reverse("expand_test:expand0")),
     ok.
 
 quoted_fun(doc) ->
@@ -93,7 +96,7 @@ quoted_fun(Config) when is_list(Config) ->
     %% should be no colon after test this time
     ?line {yes, "test", []} = edlin_expand:expand(lists:reverse("expand_")),
     ?line {no, [], []} = edlin_expand:expand(lists:reverse("expandXX_")),
-    ?line {no,[],[{"'#weird-fun-name'",0},
+    ?line {no,[],[{"'#weird-fun-name'",1},
 		  {"'Quoted_fun_name'",0},
 		  {"'Quoted_fun_too'",0},
 		  {"a_fun_name",1},
@@ -108,7 +111,7 @@ quoted_fun(Config) when is_list(Config) ->
 		   {"a_less_fun_name",1}]} = edlin_expand:expand(
 					       lists:reverse("expand_test1:a_")),
     ?line {yes,[],
-	   [{"'#weird-fun-name'",0},
+	   [{"'#weird-fun-name'",1},
 	    {"'Quoted_fun_name'",0},
 	    {"'Quoted_fun_too'",0}]} = edlin_expand:expand(
 					 lists:reverse("expand_test1:'")),
@@ -172,6 +175,6 @@ quoted_both(Config) when is_list(Config) ->
 	   [{"'Quoted_fun_name'",0},
 	    {"'Quoted_fun_too'",0}]} = edlin_expand:expand(
 					 lists:reverse("'ExpandTestCaps1':'Quoted_fun_")),
-    ?line {yes,"weird-fun-name'(",[]} = edlin_expand:expand(
-					  lists:reverse("'ExpandTestCaps1':'#")),
+    ?line {yes,"weird-fun-name'()",[]} = edlin_expand:expand(
+                                           lists:reverse("'ExpandTestCaps1':'#")),
     ok.
diff --git a/lib/stdlib/test/expand_test.erl b/lib/stdlib/test/expand_test.erl
index 63e4bc3aa0..b9db32c352 100644
--- a/lib/stdlib/test/expand_test.erl
+++ b/lib/stdlib/test/expand_test.erl
@@ -20,7 +20,8 @@
 
 -export([a_fun_name/1,
 	 a_less_fun_name/1,
-	 b_comes_after_a/1]).
+	 b_comes_after_a/1,
+         expand0arity_entirely/0]).
 
 a_fun_name(X) ->
     X.
@@ -30,3 +31,6 @@ a_less_fun_name(X) ->
 
 b_comes_after_a(X) ->
     X.
+
+expand0arity_entirely () ->
+    ok.
diff --git a/lib/stdlib/test/expand_test1.erl b/lib/stdlib/test/expand_test1.erl
index 11b6fec0f3..1d375e5677 100644
--- a/lib/stdlib/test/expand_test1.erl
+++ b/lib/stdlib/test/expand_test1.erl
@@ -23,7 +23,7 @@
 	 b_comes_after_a/1,
 	 'Quoted_fun_name'/0,
 	 'Quoted_fun_too'/0,
-	 '#weird-fun-name'/0]).
+	 '#weird-fun-name'/1]).
 
 a_fun_name(X) ->
     X.
@@ -40,5 +40,5 @@ b_comes_after_a(X) ->
 'Quoted_fun_too'() ->
     too.
 
-'#weird-fun-name'() ->
+'#weird-fun-name'(_) ->
     weird.