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authorHans Bolinder <[email protected]>2018-06-04 13:58:02 +0200
committerHans Bolinder <[email protected]>2018-06-07 08:43:20 +0200
commit380af78843891b0994f625d392fad674c1bc4fef (patch)
tree89667fe524d1343727adbe9af929b38ce748a650 /lib
parent9ae2044073e6433030ce30756658b103ce67c3c1 (diff)
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stdlib: Make pP insert no line breaks with field width zero
See also https://bugs.erlang.org/browse/ERL-607. A zero field width used to insert line breaks "everywhere", but with this patch no line breaks are inserted.
Diffstat (limited to 'lib')
-rw-r--r--lib/stdlib/doc/src/io.xml17
-rw-r--r--lib/stdlib/src/io_lib_pretty.erl2
-rw-r--r--lib/stdlib/test/io_SUITE.erl22
3 files changed, 36 insertions, 5 deletions
diff --git a/lib/stdlib/doc/src/io.xml b/lib/stdlib/doc/src/io.xml
index f1037ec76b..d4a2713840 100644
--- a/lib/stdlib/doc/src/io.xml
+++ b/lib/stdlib/doc/src/io.xml
@@ -4,7 +4,7 @@
<erlref>
<header>
<copyright>
- <year>1996</year><year>2017</year>
+ <year>1996</year><year>2018</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
@@ -332,11 +332,22 @@ Here T = [{attributes,[[{id,age,1.5},
{tag,{'PRIVATE',3}},
{mode,implicit}]
ok</pre>
+
+ <p>As from Erlang/OTP 21.0, a field width of value
+ <c>0</c> can be used for specifying that a line is
+ infinitely long, which means that no line breaks
+ are inserted. For example:</p>
+
+ <pre>
+5> <input>io:fwrite("~0p~n", [lists:seq(1, 30)]).</input>
+[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30]
+ok</pre>
+
<p>When the modifier <c>l</c> is specified, no detection of
printable character lists takes place, for example:</p>
<pre>
-5> <input>S = [{a,"a"}, {b, "b"}].</input>
-6> <input>io:fwrite("~15p~n", [S]).</input>
+6> <input>S = [{a,"a"}, {b, "b"}],
+ io:fwrite("~15p~n", [S]).</input>
[{a,"a"},
{b,"b"}]
ok
diff --git a/lib/stdlib/src/io_lib_pretty.erl b/lib/stdlib/src/io_lib_pretty.erl
index 3d5a979b3e..dca1b37ef3 100644
--- a/lib/stdlib/src/io_lib_pretty.erl
+++ b/lib/stdlib/src/io_lib_pretty.erl
@@ -131,6 +131,8 @@ print(Term, Col, Ll, D, M0, T, RecDefFun, Enc, Str) when is_tuple(Term);
%% use Len as CHAR_MAX if M0 = -1
M = max_cs(M0, Len),
if
+ Ll =:= 0 ->
+ write(If);
Len < Ll - Col, Len =< M ->
%% write the whole thing on a single line when there is room
write(If);
diff --git a/lib/stdlib/test/io_SUITE.erl b/lib/stdlib/test/io_SUITE.erl
index 13f2cbd27b..91fe1133f6 100644
--- a/lib/stdlib/test/io_SUITE.erl
+++ b/lib/stdlib/test/io_SUITE.erl
@@ -31,7 +31,7 @@
otp_10836/1, io_lib_width_too_small/1,
io_with_huge_message_queue/1, format_string/1,
maps/1, coverage/1, otp_14178_unicode_atoms/1, otp_14175/1,
- otp_14285/1, limit_term/1, otp_14983/1]).
+ otp_14285/1, limit_term/1, otp_14983/1, otp_15103/1]).
-export([pretty/2, trf/3]).
@@ -63,7 +63,7 @@ all() ->
io_lib_print_binary_depth_one, otp_10302, otp_10755, otp_10836,
io_lib_width_too_small, io_with_huge_message_queue,
format_string, maps, coverage, otp_14178_unicode_atoms, otp_14175,
- otp_14285, limit_term, otp_14983].
+ otp_14285, limit_term, otp_14983, otp_15103].
%% Error cases for output.
error_1(Config) when is_list(Config) ->
@@ -2615,3 +2615,21 @@ trf(Format, Args, T) ->
trf(Format, Args, T, Opts) ->
lists:flatten(io_lib:format(Format, Args, [{chars_limit, T}|Opts])).
+
+otp_15103(_Config) ->
+ T = lists:duplicate(5, {a,b,c}),
+
+ S1 = io_lib:format("~0p", [T]),
+ "[{a,b,c},{a,b,c},{a,b,c},{a,b,c},{a,b,c}]" = lists:flatten(S1),
+ S2 = io_lib:format("~-0p", [T]),
+ "[{a,b,c},{a,b,c},{a,b,c},{a,b,c},{a,b,c}]" = lists:flatten(S2),
+ S3 = io_lib:format("~1p", [T]),
+ "[{a,\n b,\n c},\n {a,\n b,\n c},\n {a,\n b,\n c},\n {a,\n b,\n"
+ " c},\n {a,\n b,\n c}]" = lists:flatten(S3),
+
+ S4 = io_lib:format("~0P", [T, 5]),
+ "[{a,b,c},{a,b,...},{a,...},{...}|...]" = lists:flatten(S4),
+ S5 = io_lib:format("~1P", [T, 5]),
+ "[{a,\n b,\n c},\n {a,\n b,...},\n {a,...},\n {...}|...]" =
+ lists:flatten(S5),
+ ok.