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authorHans Bolinder <[email protected]>2018-04-17 15:22:15 +0200
committerHans Bolinder <[email protected]>2018-04-25 16:23:30 +0200
commit29a347ffd408c68861a914db4efc75d8ea20a762 (patch)
tree4f51b27e734a36ce94e4800c61d3dd6ac0199f1e /lib/stdlib/src/io_lib.erl
parent513e6c069c31da33d435d16d811211eee7e16399 (diff)
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stdlib: Introduce characters limit of formated strings
Inspiration from module lager_format. Also some improvements of Unicode handling. io_lib:format/3 and io_lib:fwrite/3 are new functions. The representation of the options is a list, but we are considering using a map instead. If we change, it will happen after Erlang/OTP 21.0-rc1 is released.
Diffstat (limited to 'lib/stdlib/src/io_lib.erl')
-rw-r--r--lib/stdlib/src/io_lib.erl96
1 files changed, 73 insertions, 23 deletions
diff --git a/lib/stdlib/src/io_lib.erl b/lib/stdlib/src/io_lib.erl
index 7a520f17d9..2624d420cc 100644
--- a/lib/stdlib/src/io_lib.erl
+++ b/lib/stdlib/src/io_lib.erl
@@ -60,12 +60,12 @@
-module(io_lib).
--export([fwrite/2,fread/2,fread/3,format/2]).
--export([scan_format/2,unscan_format/1,build_text/1]).
+-export([fwrite/2,fwrite/3,fread/2,fread/3,format/2,format/3]).
+-export([scan_format/2,unscan_format/1,build_text/1,build_text/2]).
-export([print/1,print/4,indentation/2]).
-export([write/1,write/2,write/3,nl/0,format_prompt/1,format_prompt/2]).
--export([write_binary/2]).
+-export([write_binary/3]).
-export([write_atom/1,write_string/1,write_string/2,write_latin1_string/1,
write_latin1_string/2, write_char/1, write_latin1_char/1]).
@@ -88,7 +88,7 @@
-export([limit_term/2]).
-export_type([chars/0, latin1_string/0, continuation/0,
- fread_error/0, fread_item/0, format_spec/0]).
+ fread_error/0, fread_item/0, format_spec/0, chars_limit/0]).
%%----------------------------------------------------------------------
@@ -136,6 +136,18 @@
fwrite(Format, Args) ->
format(Format, Args).
+-type chars_limit() :: integer().
+
+-spec fwrite(Format, Data, Options) -> chars() when
+ Format :: io:format(),
+ Data :: [term()],
+ Options :: [Option],
+ Option :: {'chars_limit', CharsLimit},
+ CharsLimit :: chars_limit().
+
+fwrite(Format, Args, Options) ->
+ format(Format, Args, Options).
+
-spec fread(Format, String) -> Result when
Format :: string(),
String :: string(),
@@ -173,6 +185,21 @@ format(Format, Args) ->
Other
end.
+-spec format(Format, Data, Options) -> chars() when
+ Format :: io:format(),
+ Data :: [term()],
+ Options :: [Option],
+ Option :: {'chars_limit', CharsLimit},
+ CharsLimit :: chars_limit().
+
+format(Format, Args, Options) ->
+ case catch io_lib_format:fwrite(Format, Args, Options) of
+ {'EXIT',_} ->
+ erlang:error(badarg, [Format, Args, Options]);
+ Other ->
+ Other
+ end.
+
-spec scan_format(Format, Data) -> FormatList when
Format :: io:format(),
Data :: [term()],
@@ -198,6 +225,15 @@ unscan_format(FormatList) ->
build_text(FormatList) ->
io_lib_format:build(FormatList).
+-spec build_text(FormatList, Options) -> chars() when
+ FormatList :: [char() | format_spec()],
+ Options :: [Option],
+ Option :: {'chars_limit', CharsLimit},
+ CharsLimit :: chars_limit().
+
+build_text(FormatList, Options) ->
+ io_lib_format:build(FormatList, Options).
+
-spec print(Term) -> chars() when
Term :: term().
@@ -276,22 +312,25 @@ write(Term, D, false) ->
(Term, Options) -> chars() when
Term :: term(),
Options :: [Option],
- Option :: {'depth', Depth}
+ Option :: {'chars_limit', CharsLimit}
+ | {'depth', Depth}
| {'encoding', 'latin1' | 'utf8' | 'unicode'},
+ CharsLimit :: chars_limit(),
Depth :: depth().
write(Term, Options) when is_list(Options) ->
Depth = get_option(depth, Options, -1),
Encoding = get_option(encoding, Options, epp:default_encoding()),
CharsLimit = get_option(chars_limit, Options, -1),
- RecDefFun = no_fun,
- case Depth of
- 0 -> "...";
- _ when CharsLimit < 0 ->
+ if
+ Depth =:= 0; CharsLimit =:= 0 ->
+ "...";
+ CharsLimit < 0 ->
write1(Term, Depth, Encoding);
- _ when CharsLimit >= 0 ->
+ CharsLimit > 0 ->
+ RecDefFun = fun(_, _) -> no end,
If = io_lib_pretty:intermediate
- (Term, Depth, CharsLimit, RecDefFun, Encoding, _Str=false),
+ (Term, Depth, CharsLimit, RecDefFun, Encoding, _Str=false),
io_lib_pretty:write(If)
end;
write(Term, Depth) ->
@@ -361,20 +400,31 @@ write_map_assoc(K, V, D, E) ->
[write1(K, D - 1, E)," => ",write1(V, D-1, E)].
write_binary(B, D) when is_integer(D) ->
- [$<,$<,write_binary_body(B, D),$>,$>].
-
-write_binary_body(<<>>, _D) ->
- "";
-write_binary_body(_B, 1) ->
- "...";
-write_binary_body(<<X:8>>, _D) ->
- [integer_to_list(X)];
-write_binary_body(<<X:8,Rest/bitstring>>, D) ->
- [integer_to_list(X),$,|write_binary_body(Rest, D-1)];
-write_binary_body(B, _D) ->
+ {S, _} = write_binary(B, D, -1),
+ S.
+
+write_binary(B, D, T) ->
+ {S, Rest} = write_binary_body(B, D, tsub(T, 4), []),
+ {[$<,$<,lists:reverse(S),$>,$>], Rest}.
+
+write_binary_body(<<>> = B, _D, _T, Acc) ->
+ {Acc, B};
+write_binary_body(B, D, T, Acc) when D =:= 1; T =:= 0->
+ {["..."|Acc], B};
+write_binary_body(<<X:8>>, _D, _T, Acc) ->
+ {[integer_to_list(X)|Acc], <<>>};
+write_binary_body(<<X:8,Rest/bitstring>>, D, T, Acc) ->
+ S = integer_to_list(X),
+ write_binary_body(Rest, D-1, tsub(T, length(S) + 1), [$,,S|Acc]);
+write_binary_body(B, _D, _T, Acc) ->
L = bit_size(B),
<<X:L>> = B,
- [integer_to_list(X),$:,integer_to_list(L)].
+ {[integer_to_list(L),$:,integer_to_list(X)|Acc], <<>>}.
+
+%% Make sure T does not change sign.
+tsub(T, _) when T < 0 -> T;
+tsub(T, E) when T >= E -> T - E;
+tsub(_, _) -> 0.
get_option(Key, TupleList, Default) ->
case lists:keyfind(Key, 1, TupleList) of