[stdlib] Add new SDTLIB application variable 'shell_strings'

Use the new function shell:strings/1 to toggle how the Erlang shell
outputs lists of integers.

5 files changed, 54 insertions, 18 deletions

diff --git a/lib/stdlib/doc/src/shell.xml b/lib/stdlib/doc/src/shell.xml
index bc2120c37d..7f251c863e 100644
--- a/lib/stdlib/doc/src/shell.xml
+++ b/lib/stdlib/doc/src/shell.xml
@@ -4,7 +4,7 @@
 <erlref>
   <header>
     <copyright>
-      <year>1996</year><year>2011</year>
+      <year>1996</year><year>2013</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -781,7 +781,7 @@ loop(N) ->
       </desc>
     </func>
     <func>
-      <name>catch_exception(Bool) -> Bool</name>
+      <name>catch_exception(Bool) -> boolean()</name>
       <fsummary>Sets the exception handling of the shell</fsummary>
       <type>
         <v>Bool = boolean()</v>
@@ -801,8 +801,8 @@ loop(N) ->
       <name name="prompt_func" arity="1"/>
       <fsummary>Sets the shell prompt</fsummary>
       <desc>
-        <p>Sets the shell prompt function to <c>PromptFunc</c>. The
-          previous prompt function is returned.</p>
+        <p>Sets the shell prompt function to <c><anno>PromptFunc</anno></c>.
+          The previous prompt function is returned.</p>
       </desc>
     </func>
     <func>
@@ -827,6 +827,20 @@ loop(N) ->
           is meant to be called from the shell.</p>
       </desc>
     </func>
+    <func>
+      <name name="strings" arity="1"/>
+      <fsummary>Sets the shell's string recognition flag.</fsummary>
+      <desc>
+        <p>Sets pretty printing of lists to <c><anno>Strings</anno></c>.
+          The previous value of the flag is returned.</p>
+        <p>The flag can also be set by the STDLIB application variable
+          <c>shell_strings</c>. The default is
+          <c>true</c> which means that lists of integers will be
+          printed using the string syntax, when possible. The value
+          <c>false</c> means that no lists will be printed using the
+          string syntax.</p>
+      </desc>
+    </func>
   </funcs>
 </erlref>
 
diff --git a/lib/stdlib/doc/src/stdlib_app.xml b/lib/stdlib/doc/src/stdlib_app.xml
index a615c1bf88..2391bb6f03 100644
--- a/lib/stdlib/doc/src/stdlib_app.xml
+++ b/lib/stdlib/doc/src/stdlib_app.xml
@@ -4,7 +4,7 @@
 <appref>
   <header>
     <copyright>
-      <year>2005</year><year>2010</year>
+      <year>2005</year><year>2013</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -51,7 +51,7 @@
         <p>This parameter can be used to run the Erlang shell
           in restricted mode.</p>
       </item>
-      <tag><c>shell_catch_exception = bool()</c></tag>
+      <tag><c>shell_catch_exception = boolean()</c></tag>
       <item>
         <p>This parameter can be used to set the exception handling
 	  of the Erlang shell's evaluator process.</p>
@@ -76,6 +76,11 @@
         <p>This parameter can be used to determine how many 
           results are saved by the Erlang shell.</p>
       </item>
+      <tag><c>shell_strings = boolean()</c></tag>
+      <item>
+        <p>This parameter can be used to determine how the Erlang
+          shell outputs lists of integers.</p>
+      </item>
     </taglist>
   </section>
 
diff --git a/lib/stdlib/src/io_lib_format.erl b/lib/stdlib/src/io_lib_format.erl
index 19eccf9355..56e15a17ec 100644
--- a/lib/stdlib/src/io_lib_format.erl
+++ b/lib/stdlib/src/io_lib_format.erl
@@ -58,7 +58,7 @@ collect_cseq(Fmt0, Args0) ->
     {P,Fmt2,Args2} = precision(Fmt1, Args1),
     {Pad,Fmt3,Args3} = pad_char(Fmt2, Args2),
     {Encoding,Fmt4,Args4} = encoding(Fmt3, Args3),
-    {Strings,Fmt5,Args5} = pretty_lists(Fmt4, Args4),
+    {Strings,Fmt5,Args5} = strings(Fmt4, Args4),
     {C,As,Fmt6,Args6} = collect_cc(Fmt5, Args5),
     {{C,As,F,Ad,P,Pad,Encoding,Strings},Fmt6,Args6}.
 
@@ -68,11 +68,11 @@ encoding([$t|Fmt],Args) ->
 encoding(Fmt,Args) ->
     {latin1,Fmt,Args}.
 
-pretty_lists([$l|Fmt],Args) ->
+strings([$l|Fmt],Args) ->
     true = hd(Fmt) =/= $t,
-    {no,Fmt,Args};
-pretty_lists(Fmt,Args) ->
-    {unicode,Fmt,Args}.
+    {false,Fmt,Args};
+strings(Fmt,Args) ->
+    {true,Fmt,Args}.
 
 field_width([$-|Fmt0], Args0) ->
     {F,Fmt,Args} = field_value(Fmt0, Args0),
diff --git a/lib/stdlib/src/io_lib_pretty.erl b/lib/stdlib/src/io_lib_pretty.erl
index c7d2ad97c7..525b534249 100644
--- a/lib/stdlib/src/io_lib_pretty.erl
+++ b/lib/stdlib/src/io_lib_pretty.erl
@@ -56,7 +56,7 @@ print(Term) ->
                 | {depth, depth()}
                 | {max_chars, max_chars()}
                 | {record_print_fun, rec_print_fun()}
-                | {strings, io_lib:pretty_lists()}
+                | {strings, boolean()}
                 | {encoding, latin1 | utf8 | unicode}.
 -type options() :: [option()].
 
@@ -332,7 +332,7 @@ print_length([], _D, _RF, _Enc, _Str) ->
 print_length({}, _D, _RF, _Enc, _Str) ->
     {"{}", 2};
 print_length(List, D, RF, Enc, Str) when is_list(List) ->
-    case Str =:= unicode andalso printable_list(List, D, Enc) of
+    case Str andalso printable_list(List, D, Enc) of
         true ->
             S = write_string(List, Enc),
             {S, length(S)};
@@ -364,7 +364,7 @@ print_length(<<_/bitstring>>=Bin, D, _RF, Enc, Str) ->
     case bit_size(Bin) rem 8 of
         0 ->
 	    D1 = D - 1, 
-	    case Str =:= unicode andalso printable_bin(Bin, D1, Enc) of
+	    case Str andalso printable_bin(Bin, D1, Enc) of
                 {true, List} when is_list(List) ->
                     S = io_lib:write_string(List, $"), %"
 	            {[$<,$<,S,$>,$>], 4 + length(S)};
diff --git a/lib/stdlib/src/shell.erl b/lib/stdlib/src/shell.erl
index c94f052b24..df66acb97b 100644
--- a/lib/stdlib/src/shell.erl
+++ b/lib/stdlib/src/shell.erl
@@ -22,7 +22,7 @@
 -export([whereis_evaluator/0, whereis_evaluator/1]).
 -export([start_restricted/1, stop_restricted/0]).
 -export([local_allowed/3, non_local_allowed/3]).
--export([prompt_func/1]).
+-export([prompt_func/1, strings/1]).
 
 -define(LINEMAX, 30).
 -define(CHAR_MAX, 60).
@@ -30,6 +30,7 @@
 -define(DEF_RESULTS, 20).
 -define(DEF_CATCH_EXCEPTION, false).
 -define(DEF_PROMPT_FUNC, default).
+-define(DEF_STRINGS, true).
 
 -define(RECORDS, shell_records).
 
@@ -1366,8 +1367,16 @@ pp(V, I, RT) ->
     pp(V, I, RT, enc()).
 
 pp(V, I, RT, Enc) ->
+    Strings =
+        case application:get_env(stdlib, shell_strings) of
+            {ok, false} ->
+                false;
+            _ ->
+                true
+        end,
     io_lib_pretty:print(V, ([{column, I}, {line_length, columns()},
                              {depth, ?LINEMAX}, {max_chars, ?CHAR_MAX},
+                             {strings, Strings},
                              {record_print_fun, record_print_fun(RT)}]
                             ++ Enc)).
 
@@ -1444,14 +1453,22 @@ history(L) when is_integer(L), L >= 0 ->
 results(L) when is_integer(L), L >= 0 ->
     set_env(stdlib, shell_saved_results, L, ?DEF_RESULTS).
 
--spec catch_exception(Bool) -> Bool when
+-spec catch_exception(Bool) -> boolean() when
       Bool :: boolean().
 
 catch_exception(Bool) ->
     set_env(stdlib, shell_catch_exception, Bool, ?DEF_CATCH_EXCEPTION).
 
--spec prompt_func(PromptFunc) -> PromptFunc when
-      PromptFunc :: 'default' | {module(),atom()}.
+-spec prompt_func(PromptFunc) -> PromptFunc2 when
+      PromptFunc :: 'default' | {module(),atom()},
+      PromptFunc2 :: 'default' | {module(),atom()}.
 
 prompt_func(String) ->
     set_env(stdlib, shell_prompt_func, String, ?DEF_PROMPT_FUNC).
+
+-spec strings(Strings) -> Strings2 when
+      Strings :: boolean(),
+      Strings2 :: boolean().
+
+strings(Strings) ->
+    set_env(stdlib, shell_strings, Strings, ?DEF_STRINGS).