stdlib: Improve Erlang shell's tab-completion of long names

1 files changed, 76 insertions, 3 deletions

diff --git a/lib/stdlib/test/edlin_expand_SUITE.erl b/lib/stdlib/test/edlin_expand_SUITE.erl
index 718d91c6a3..1f694ea549 100644
--- a/lib/stdlib/test/edlin_expand_SUITE.erl
+++ b/lib/stdlib/test/edlin_expand_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2016. All Rights Reserved.
+%% Copyright Ericsson AB 2010-2017. 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.
@@ -21,7 +21,8 @@
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 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]).
+-export([normal/1, quoted_fun/1, quoted_module/1, quoted_both/1, erl_1152/1,
+         erl_352/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -36,7 +37,7 @@ suite() ->
      {timetrap,{minutes,1}}].
 
 all() -> 
-    [normal, quoted_fun, quoted_module, quoted_both, erl_1152].
+    [normal, quoted_fun, quoted_module, quoted_both, erl_1152, erl_352].
 
 groups() -> 
     [].
@@ -153,6 +154,78 @@ erl_1152(Config) when is_list(Config) ->
     "\n"++"foo"++"    "++[1089]++_ = do_format(["foo",[1089]]),
     ok.
 
+erl_352(Config) when is_list(Config) ->
+    erl_352_test(3, 3),
+
+    erl_352_test(3, 75),
+    erl_352_test(3, 76, [trailing]),
+    erl_352_test(4, 74),
+    erl_352_test(4, 75, [leading]),
+    erl_352_test(4, 76, [leading, trailing]),
+
+    erl_352_test(75, 3),
+    erl_352_test(76, 3, [leading]),
+    erl_352_test(74, 4),
+    erl_352_test(75, 4, [leading]),
+    erl_352_test(76, 4, [leading]),
+
+    erl_352_test(74, 74, [leading]),
+    erl_352_test(74, 75, [leading]),
+    erl_352_test(74, 76, [leading, trailing]).
+
+erl_352_test(PrefixLen, SuffixLen) ->
+    erl_352_test(PrefixLen, SuffixLen, []).
+
+erl_352_test(PrefixLen, SuffixLen, Dots) ->
+    io:format("\nPrefixLen = ~w, SuffixLen = ~w\n", [PrefixLen, SuffixLen]),
+
+    PrefixM = lists:duplicate(PrefixLen, $p),
+    SuffixM = lists:duplicate(SuffixLen, $s),
+    LM = [PrefixM ++ S ++ SuffixM || S <- ["1", "2"]],
+    StrM = do_format(LM),
+    check_leading(StrM, "", PrefixM, SuffixM, Dots),
+
+    PrefixF = lists:duplicate(PrefixLen, $p),
+    SuffixF = lists:duplicate(SuffixLen-2, $s),
+    LF = [{PrefixF ++ S ++ SuffixF, 1} || S <- ["1", "2"]],
+    StrF = do_format(LF),
+    true = check_leading(StrF, "/1", PrefixF, SuffixF, Dots),
+
+    ok.
+
+check_leading(FormStr, ArityStr, Prefix, Suffix, Dots) ->
+    List = string:tokens(FormStr, "\n "),
+    io:format("~p\n", [List]),
+    true = lists:all(fun(L) -> length(L) < 80 end, List),
+    case lists:member(leading, Dots) of
+        true ->
+            true = lists:all(fun(L) ->
+                                     {"...", Rest} = lists:split(3, L),
+                                     check_trailing(Rest, ArityStr,
+                                                    Suffix, Dots)
+                             end, List);
+        false ->
+            true = lists:all(fun(L) ->
+                                     {Prefix, Rest} =
+                                         lists:split(length(Prefix), L),
+                                     check_trailing(Rest, ArityStr,
+                                                    Suffix, Dots)
+                             end, List)
+    end.
+
+check_trailing([I|Str], ArityStr, Suffix, Dots) ->
+    true = lists:member(I, [$1, $2]),
+    case lists:member(trailing, Dots) of
+        true ->
+            {Rest, "..." ++ ArityStr} =
+                lists:split(length(Str) - (3 + length(ArityStr)), Str),
+            true = lists:prefix(Rest, Suffix);
+        false ->
+            {Rest, ArityStr} =
+                lists:split(length(Str) - length(ArityStr), Str),
+            Rest =:= Suffix
+    end.
+
 do_expand(String) ->
     edlin_expand:expand(lists:reverse(String)).