stdlib: Improve handling of Unicode in edlin_expand

4 files changed, 76 insertions, 13 deletions

diff --git a/lib/stdlib/src/edlin_expand.erl b/lib/stdlib/src/edlin_expand.erl
index a1a97af4c5..bdcefda6e5 100644
--- a/lib/stdlib/src/edlin_expand.erl
+++ b/lib/stdlib/src/edlin_expand.erl
@@ -23,7 +23,7 @@
 
 -export([expand/1, format_matches/1]).
 
--import(lists, [reverse/1, nthtail/2, prefix/2]).
+-import(lists, [reverse/1, prefix/2]).
 
 %% expand(CurrentBefore) ->
 %%	{yes, Expansion, Matches} | {no, Matches}
@@ -75,15 +75,15 @@ to_atom(Str) ->
     end.
 
 match(Prefix, Alts, Extra0) ->
-    Len = length(Prefix),
+    Len = string:length(Prefix),
     Matches = lists:sort(
 		[{S, A} || {H, A} <- Alts,
-			   prefix(Prefix, S=hd(io_lib:fwrite("~w",[H])))]),
+			   prefix(Prefix, S=flat_write(H))]),
     case longest_common_head([N || {N, _} <- Matches]) of
  	{partial, []} ->
  	    {no, [], Matches}; % format_matches(Matches)};
  	{partial, Str} ->
- 	    case nthtail(Len, Str) of
+            case string:slice(Str, Len) of
  		[] ->
 		    {yes, [], Matches}; % format_matches(Matches)};
  		Remain ->
@@ -94,18 +94,21 @@ match(Prefix, Alts, Extra0) ->
 			{"(",[{Str,0}]} -> "()";
 			{_,_} -> Extra0
 		    end,
-	    {yes, nthtail(Len, Str) ++ Extra, []};
+	    {yes, string:slice(Str, Len) ++ Extra, []};
  	no ->
  	    {no, [], []}
     end.
 
+flat_write(T) ->
+    lists:flatten(io_lib:fwrite("~tw",[T])).
+
 %% Return the list of names L in multiple columns.
 format_matches(L) ->
     {S1, Dots} = format_col(lists:sort(L), []),
     S = case Dots of
             true ->
                 {_, Prefix} = longest_common_head(vals(L)),
-                PrefixLen = length(Prefix),
+                PrefixLen = string:length(Prefix),
                 case PrefixLen =< 3 of
                     true -> S1; % Do not replace the prefix with "...".
                     false ->
@@ -128,7 +131,7 @@ format_col([A|T], Width, Len, Acc0, LL, Dots) ->
     {H0, R} = format_val(A),
     Hmax = LL - length(R),
     {H, NewDots} =
-        case length(H0) > Hmax of
+        case string:length(H0) > Hmax of
             true -> {io_lib:format("~-*ts", [Hmax - 3, H0]) ++ "...", true};
             false -> {H0, Dots}
         end,
@@ -149,12 +152,12 @@ format_val(H) ->
 field_width(L, LL) -> field_width(L, 0, LL).
 
 field_width([{H,_}|T], W, LL) ->
-    case length(H) of
+    case string:length(H) of
         L when L > W -> field_width(T, L, LL);
         _ -> field_width(T, W, LL)
     end;
 field_width([H|T], W, LL) ->
-    case length(H) of
+    case string:length(H) of
         L when L > W -> field_width(T, L, LL);
         _ -> field_width(T, W, LL)
     end;
@@ -169,10 +172,11 @@ vals([S|L]) -> [S|vals(L)].
 
 leading_dots([], _Len) -> [];
 leading_dots([{H, I}|L], Len) ->
-    [{"..." ++ nthtail(Len, H), I}|leading_dots(L, Len)];
+    [{"..." ++ string:slice(H, Len), I}|leading_dots(L, Len)];
 leading_dots([H|L], Len) ->
-    ["..." ++ nthtail(Len, H)|leading_dots(L, Len)].
+    ["..." ++ string:slice(H, Len)|leading_dots(L, Len)].
 
+%% Strings are handled naively, but it should be OK here.
 longest_common_head([]) ->
     no;
 longest_common_head(LL) ->
diff --git a/lib/stdlib/test/Makefile b/lib/stdlib/test/Makefile
index 72211332e9..7b79dcf04d 100644
--- a/lib/stdlib/test/Makefile
+++ b/lib/stdlib/test/Makefile
@@ -36,6 +36,7 @@ MODULES= \
 	ets_tough_SUITE \
 	expand_test \
 	expand_test1 \
+	unicode_expand \
 	ExpandTestCaps \
 	ExpandTestCaps1 \
 	filelib_SUITE \
diff --git a/lib/stdlib/test/edlin_expand_SUITE.erl b/lib/stdlib/test/edlin_expand_SUITE.erl
index 1f694ea549..5c2b1965ba 100644
--- a/lib/stdlib/test/edlin_expand_SUITE.erl
+++ b/lib/stdlib/test/edlin_expand_SUITE.erl
@@ -22,7 +22,7 @@
 	 init_per_testcase/2, end_per_testcase/2,
 	 init_per_group/2,end_per_group/2]).
 -export([normal/1, quoted_fun/1, quoted_module/1, quoted_both/1, erl_1152/1,
-         erl_352/1]).
+         erl_352/1, unicode/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -37,7 +37,8 @@ suite() ->
      {timetrap,{minutes,1}}].
 
 all() -> 
-    [normal, quoted_fun, quoted_module, quoted_both, erl_1152, erl_352].
+    [normal, quoted_fun, quoted_module, quoted_both, erl_1152, erl_352,
+     unicode].
 
 groups() -> 
     [].
@@ -150,6 +151,7 @@ quoted_both(Config) when is_list(Config) ->
     {yes,"weird-fun-name'()",[]} = do_expand("'ExpandTestCaps1':'#"),
     ok.
 
+%% Note: pull request #1152.
 erl_1152(Config) when is_list(Config) ->
     "\n"++"foo"++"    "++[1089]++_ = do_format(["foo",[1089]]),
     ok.
@@ -226,6 +228,26 @@ check_trailing([I|Str], ArityStr, Suffix, Dots) ->
             Rest =:= Suffix
     end.
 
+unicode(Config) when is_list(Config) ->
+    {module,unicode_expand} = c:l('unicode_expand'),
+    {no,[],[{"'кlирилли́ческий атом'",0},
+            {"'кlирилли́ческий атом'",1},
+            {"'кlирилли́ческий атомB'",1},
+            {"module_info",0},
+            {"module_info",1}]} = do_expand("unicode_expand:"),
+    {yes,"рилли́ческий атом", []} = do_expand("unicode_expand:'кlи"),
+    {yes,"еский атом", []} = do_expand("unicode_expand:'кlирилли́ч"),
+    {yes,"(",[]} = do_expand("unicode_expand:'кlирилли́ческий атомB'"),
+    "\n'кlирилли́ческий атом'/0   'кlирилли́ческий атом'/1   "
+    "'кlирилли́ческий атомB'/1  \nmodule_info/0             "
+    "module_info/1             \n" =
+        do_format([{"'кlирилли́ческий атом'",0},
+                   {"'кlирилли́ческий атом'",1},
+                   {"'кlирилли́ческий атомB'",1},
+                   {"module_info",0},
+                   {"module_info",1}]),
+    ok.
+
 do_expand(String) ->
     edlin_expand:expand(lists:reverse(String)).
 
diff --git a/lib/stdlib/test/unicode_expand.erl b/lib/stdlib/test/unicode_expand.erl
new file mode 100644
index 0000000000..41f741fa84
--- /dev/null
+++ b/lib/stdlib/test/unicode_expand.erl
@@ -0,0 +1,36 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(unicode_expand).
+
+-export(['кlирилли́ческий атом'/0, 'кlирилли́ческий атом'/1,
+        'кlирилли́ческий атомB'/1]).
+
+-export_type(['кlирилли́ческий атом'/0]).
+
+-type 'кlирилли́ческий атом'() :: integer().
+
+'кlирилли́ческий атом'() ->
+    'кlирилли́ческий атом'('кlирилли́ческий атом').
+
+'кlирилли́ческий атом'(_Atom) ->
+    ok.
+
+'кlирилли́ческий атомB'(_B) ->
+    true.