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authorRichard Carlsson <[email protected]>2018-03-08 12:31:49 +0100
committerRichard Carlsson <[email protected]>2018-03-12 16:24:33 +0100
commit9c1cb443a22679f038451b4491c4c50ec53f77a2 (patch)
treecf7f3541e6328a9714dda83147b232ca4460a554 /lib/stdlib
parent1f90069ac153214a0510fa862361e1e31d558b91 (diff)
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Allow multiple modifier characters in io:format control sequences
This makes it possible to print unicode atoms at the same time as suppressing detection of printable lists.
Diffstat (limited to 'lib/stdlib')
-rw-r--r--lib/stdlib/doc/src/io.xml33
-rw-r--r--lib/stdlib/src/erl_lint.erl8
-rw-r--r--lib/stdlib/src/io_lib_format.erl36
-rw-r--r--lib/stdlib/test/io_SUITE.erl56
4 files changed, 92 insertions, 41 deletions
diff --git a/lib/stdlib/doc/src/io.xml b/lib/stdlib/doc/src/io.xml
index 6a7c06188b..f1037ec76b 100644
--- a/lib/stdlib/doc/src/io.xml
+++ b/lib/stdlib/doc/src/io.xml
@@ -137,11 +137,11 @@
Hello world!
ok</pre>
<p>The general format of a control sequence is <c>~F.P.PadModC</c>.</p>
- <p>Character <c>C</c> determines the type of control sequence
- to be used, <c>F</c> and <c>P</c> are optional numeric
- arguments. If <c>F</c>, <c>P</c>, or <c>Pad</c> is <c>*</c>,
- the next argument in <c>Data</c> is used as the numeric value
- of <c>F</c> or <c>P</c>.</p>
+ <p>The character <c>C</c> determines the type of control sequence
+ to be used. It is the only required field. All of <c>F</c>,
+ <c>P</c>, <c>Pad</c>, and <c>Mod</c> are optional. For example,
+ to use a <c>#</c> for <c>Pad</c> but use the default values for
+ <c>F</c> and <c>P</c>, you can write <c>~..#C</c>.</p>
<list type="bulleted">
<item>
<p><c>F</c> is the <c>field width</c> of the printed argument. A
@@ -167,13 +167,26 @@ ok</pre>
The default padding character is <c>' '</c> (space).</p>
</item>
<item>
- <p><c>Mod</c> is the control sequence modifier. It is a
- single character that changes the interpretation of
- <c>Data</c>. This can be <c>t</c>, for Unicode translation,
- or <c>l</c>, for stopping <c>p</c> and <c>P</c> from
- detecting printable characters.</p>
+ <p><c>Mod</c> is the control sequence modifier. This is
+ one or more characters that change the interpretation of
+ <c>Data</c>. The current modifiers are <c>t</c>, for Unicode
+ translation, and <c>l</c>, for stopping <c>p</c> and <c>P</c>
+ from detecting printable characters.</p>
</item>
</list>
+ <p>If <c>F</c>, <c>P</c>, or <c>Pad</c> is a <c>*</c> character,
+ the next argument in <c>Data</c> is used as the value.
+ For example:</p>
+ <pre>
+1> <input>io:fwrite("~*.*.0f~n",[9, 5, 3.14159265]).</input>
+003.14159
+ok</pre>
+ <p>To use a literal <c>*</c> character as <c>Pad</c>, it must be
+ passed as an argument:</p>
+ <pre>
+2> <input>io:fwrite("~*.*.*f~n",[9, 5, $*, 3.14159265]).</input>
+**3.14159
+ok</pre>
<p><em>Available control sequences:</em></p>
<taglist>
<tag><c>~</c></tag>
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 1930c462e8..9a62d21d34 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -3971,6 +3971,8 @@ extract_sequence(3, [$.,_|Fmt], Need) ->
extract_sequence(4, Fmt, Need);
extract_sequence(3, Fmt, Need) ->
extract_sequence(4, Fmt, Need);
+extract_sequence(4, [$t, $l | Fmt], Need) ->
+ extract_sequence(4, [$l, $t | Fmt], Need);
extract_sequence(4, [$t, $c | Fmt], Need) ->
extract_sequence(5, [$c|Fmt], Need);
extract_sequence(4, [$t, $s | Fmt], Need) ->
@@ -3987,8 +3989,14 @@ extract_sequence(4, [$t, C | _Fmt], _Need) ->
{error,"invalid control ~t" ++ [C]};
extract_sequence(4, [$l, $p | Fmt], Need) ->
extract_sequence(5, [$p|Fmt], Need);
+extract_sequence(4, [$l, $t, $p | Fmt], Need) ->
+ extract_sequence(5, [$p|Fmt], Need);
extract_sequence(4, [$l, $P | Fmt], Need) ->
extract_sequence(5, [$P|Fmt], Need);
+extract_sequence(4, [$l, $t, $P | Fmt], Need) ->
+ extract_sequence(5, [$P|Fmt], Need);
+extract_sequence(4, [$l, $t, C | _Fmt], _Need) ->
+ {error,"invalid control ~lt" ++ [C]};
extract_sequence(4, [$l, C | _Fmt], _Need) ->
{error,"invalid control ~l" ++ [C]};
extract_sequence(4, Fmt, Need) ->
diff --git a/lib/stdlib/src/io_lib_format.erl b/lib/stdlib/src/io_lib_format.erl
index e345810ca0..3e1f90ac24 100644
--- a/lib/stdlib/src/io_lib_format.erl
+++ b/lib/stdlib/src/io_lib_format.erl
@@ -126,25 +126,23 @@ collect_cseq(Fmt0, Args0) ->
{F,Ad,Fmt1,Args1} = field_width(Fmt0, Args0),
{P,Fmt2,Args2} = precision(Fmt1, Args1),
{Pad,Fmt3,Args3} = pad_char(Fmt2, Args2),
- {Encoding,Fmt4,Args4} = encoding(Fmt3, Args3),
- {Strings,Fmt5,Args5} = strings(Fmt4, Args4),
- {C,As,Fmt6,Args6} = collect_cc(Fmt5, Args5),
- FormatSpec = #{control_char => C, args => As, width => F, adjust => Ad,
- precision => P, pad_char => Pad, encoding => Encoding,
- strings => Strings},
- {FormatSpec,Fmt6,Args6}.
-
-encoding([$t|Fmt],Args) ->
- true = hd(Fmt) =/= $l,
- {unicode,Fmt,Args};
-encoding(Fmt,Args) ->
- {latin1,Fmt,Args}.
-
-strings([$l|Fmt],Args) ->
- true = hd(Fmt) =/= $t,
- {false,Fmt,Args};
-strings(Fmt,Args) ->
- {true,Fmt,Args}.
+ Spec0 = #{width => F,
+ adjust => Ad,
+ precision => P,
+ pad_char => Pad,
+ encoding => latin1,
+ strings => true},
+ {Spec1,Fmt4} = modifiers(Fmt3, Spec0),
+ {C,As,Fmt5,Args4} = collect_cc(Fmt4, Args3),
+ Spec2 = Spec1#{control_char => C, args => As},
+ {Spec2,Fmt5,Args4}.
+
+modifiers([$t|Fmt], Spec) ->
+ modifiers(Fmt, Spec#{encoding => unicode});
+modifiers([$l|Fmt], Spec) ->
+ modifiers(Fmt, Spec#{strings => false});
+modifiers(Fmt, Spec) ->
+ {Spec, Fmt}.
field_width([$-|Fmt0], Args0) ->
{F,Fmt,Args} = field_value(Fmt0, Args0),
diff --git a/lib/stdlib/test/io_SUITE.erl b/lib/stdlib/test/io_SUITE.erl
index 45363c0592..46e96a8284 100644
--- a/lib/stdlib/test/io_SUITE.erl
+++ b/lib/stdlib/test/io_SUITE.erl
@@ -1905,29 +1905,61 @@ otp_10836(Suite) when is_list(Suite) ->
%% OTP-10755. The 'l' modifier
otp_10755(Suite) when is_list(Suite) ->
+ %% printing plain ascii characters
S = "string",
"\"string\"" = fmt("~p", [S]),
"[115,116,114,105,110,103]" = fmt("~lp", [S]),
"\"string\"" = fmt("~P", [S, 2]),
"[115|...]" = fmt("~lP", [S, 2]),
- {'EXIT',{badarg,_}} = (catch fmt("~ltp", [S])),
- {'EXIT',{badarg,_}} = (catch fmt("~tlp", [S])),
- {'EXIT',{badarg,_}} = (catch fmt("~ltP", [S])),
- {'EXIT',{badarg,_}} = (catch fmt("~tlP", [S])),
+ %% printing latin1 chars, with and without modifiers
+ T = {[255],list_to_atom([255]),[a,b,c]},
+ "{\"ÿ\",ÿ,[a,b,c]}" = fmt("~p", [T]),
+ "{\"ÿ\",ÿ,[a,b,c]}" = fmt("~tp", [T]),
+ "{[255],ÿ,[a,b,c]}" = fmt("~lp", [T]),
+ "{[255],ÿ,[a,b,c]}" = fmt("~ltp", [T]),
+ "{[255],ÿ,[a,b,c]}" = fmt("~tlp", [T]),
+ "{\"ÿ\",ÿ,...}" = fmt("~P", [T,3]),
+ "{\"ÿ\",ÿ,...}" = fmt("~tP", [T,3]),
+ "{[255],ÿ,...}" = fmt("~lP", [T,3]),
+ "{[255],ÿ,...}" = fmt("~ltP", [T,3]),
+ "{[255],ÿ,...}" = fmt("~tlP", [T,3]),
+ %% printing unicode chars, with and without modifiers
+ U = {[666],list_to_atom([666]),[a,b,c]},
+ "{[666],'\\x{29A}',[a,b,c]}" = fmt("~p", [U]),
+ case io:printable_range() of
+ unicode ->
+ "{\"ʚ\",'ʚ',[a,b,c]}" = fmt("~tp", [U]),
+ "{\"ʚ\",'ʚ',...}" = fmt("~tP", [U,3]);
+ latin1 ->
+ "{[666],'ʚ',[a,b,c]}" = fmt("~tp", [U]),
+ "{[666],'ʚ',...}" = fmt("~tP", [U,3])
+ end,
+ "{[666],'\\x{29A}',[a,b,c]}" = fmt("~lp", [U]),
+ "{[666],'ʚ',[a,b,c]}" = fmt("~ltp", [U]),
+ "{[666],'ʚ',[a,b,c]}" = fmt("~tlp", [U]),
+ "{[666],'\\x{29A}',...}" = fmt("~P", [U,3]),
+ "{[666],'\\x{29A}',...}" = fmt("~lP", [U,3]),
+ "{[666],'ʚ',...}" = fmt("~ltP", [U,3]),
+ "{[666],'ʚ',...}" = fmt("~tlP", [U,3]),
+ %% the compiler should catch uses of ~l with other than pP
Text =
"-module(l_mod).\n"
"-export([t/0]).\n"
"t() ->\n"
" S = \"string\",\n"
- " io:format(\"~ltp\", [S]),\n"
- " io:format(\"~tlp\", [S]),\n"
- " io:format(\"~ltP\", [S, 1]),\n"
- " io:format(\"~tlP\", [S, 1]).\n",
+ " io:format(\"~lw\", [S]),\n"
+ " io:format(\"~lW\", [S, 1]),\n"
+ " io:format(\"~ltw\", [S]),\n"
+ " io:format(\"~tlw\", [S]),\n"
+ " io:format(\"~ltW\", [S, 1]),\n"
+ " io:format(\"~tlW\", [S, 1]).\n",
{ok,l_mod,[{_File,Ws}]} = compile_file("l_mod.erl", Text, Suite),
- ["format string invalid (invalid control ~lt)",
- "format string invalid (invalid control ~tl)",
- "format string invalid (invalid control ~lt)",
- "format string invalid (invalid control ~tl)"] =
+ ["format string invalid (invalid control ~lw)",
+ "format string invalid (invalid control ~lW)",
+ "format string invalid (invalid control ~ltw)",
+ "format string invalid (invalid control ~ltw)",
+ "format string invalid (invalid control ~ltW)",
+ "format string invalid (invalid control ~ltW)"] =
[lists:flatten(M:format_error(E)) || {_L,M,E} <- Ws],
ok.