diff options
Diffstat (limited to 'lib/stdlib/src/io_lib_format.erl')
| -rw-r--r-- | lib/stdlib/src/io_lib_format.erl | 327 |
1 files changed, 208 insertions, 119 deletions
diff --git a/lib/stdlib/src/io_lib_format.erl b/lib/stdlib/src/io_lib_format.erl index 282005da7d..ab9031573b 100644 --- a/lib/stdlib/src/io_lib_format.erl +++ b/lib/stdlib/src/io_lib_format.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1996-2014. All Rights Reserved. +%% Copyright Ericsson AB 1996-2018. 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 @@ %% Formatting functions of io library. --export([fwrite/2,fwrite_g/1,indentation/2,scan/2,unscan/1,build/1]). +-export([fwrite/2,fwrite/3,fwrite_g/1,indentation/2,scan/2,unscan/1, + build/1, build/2]). %% Format the arguments in Args after string Format. Just generate %% an error if there is an error in the arguments. @@ -37,22 +38,48 @@ %% and it also splits the handling of the control characters into two %% parts. --spec fwrite(Format, Data) -> FormatList when +-spec fwrite(Format, Data) -> io_lib:chars() when Format :: io:format(), - Data :: [term()], - FormatList :: [char() | io_lib:format_spec()]. + Data :: [term()]. fwrite(Format, Args) -> build(scan(Format, Args)). +-spec fwrite(Format, Data, Options) -> io_lib:chars() when + Format :: io:format(), + Data :: [term()], + Options :: [Option], + Option :: {'chars_limit', CharsLimit}, + CharsLimit :: io_lib:chars_limit(). + +fwrite(Format, Args, Options) -> + build(scan(Format, Args), Options). + %% Build the output text for a pre-parsed format list. -spec build(FormatList) -> io_lib:chars() when FormatList :: [char() | io_lib:format_spec()]. build(Cs) -> - Pc = pcount(Cs), - build(Cs, Pc, 0). + build(Cs, []). + +-spec build(FormatList, Options) -> io_lib:chars() when + FormatList :: [char() | io_lib:format_spec()], + Options :: [Option], + Option :: {'chars_limit', CharsLimit}, + CharsLimit :: io_lib:chars_limit(). + +build(Cs, Options) -> + CharsLimit = get_option(chars_limit, Options, -1), + Res1 = build_small(Cs), + {P, S, W, Other} = count_small(Res1), + case P + S + W of + 0 -> + Res1; + NumOfLimited -> + RemainingChars = sub(CharsLimit, Other), + build_limited(Res1, P, NumOfLimited, RemainingChars, 0) + end. %% Parse all control sequences in the format string. @@ -95,7 +122,7 @@ print([]) -> []. print(C, F, Ad, P, Pad, Encoding, Strings) -> - [$~] ++ print_field_width(F, Ad) ++ print_precision(P) ++ + [$~] ++ print_field_width(F, Ad) ++ print_precision(P, Pad) ++ print_pad_char(Pad) ++ print_encoding(Encoding) ++ print_strings(Strings) ++ [C]. @@ -103,8 +130,9 @@ print_field_width(none, _Ad) -> ""; print_field_width(F, left) -> integer_to_list(-F); print_field_width(F, right) -> integer_to_list(F). -print_precision(none) -> ""; -print_precision(P) -> [$. | integer_to_list(P)]. +print_precision(none, $\s) -> ""; +print_precision(none, _Pad) -> "."; % pad must be second dot +print_precision(P, _Pad) -> [$. | integer_to_list(P)]. print_pad_char($\s) -> ""; % default, no need to make explicit print_pad_char(Pad) -> [$., Pad]. @@ -126,25 +154,23 @@ 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), @@ -203,40 +229,78 @@ collect_cc([$~|Fmt], Args) when is_list(Args) -> {$~,[],Fmt,Args}; collect_cc([$n|Fmt], Args) when is_list(Args) -> {$n,[],Fmt,Args}; collect_cc([$i|Fmt], [A|Args]) -> {$i,[A],Fmt,Args}. -%% pcount([ControlC]) -> Count. -%% Count the number of print requests. - -pcount(Cs) -> pcount(Cs, 0). - -pcount([#{control_char := $p}|Cs], Acc) -> pcount(Cs, Acc+1); -pcount([#{control_char := $P}|Cs], Acc) -> pcount(Cs, Acc+1); -pcount([_|Cs], Acc) -> pcount(Cs, Acc); -pcount([], Acc) -> Acc. - -%% build([Control], Pc, Indentation) -> io_lib:chars(). +%% count_small([ControlC]) -> Count. +%% Count the number of big (pPwWsS) print requests and +%% number of characters of other print (small) requests. + +count_small(Cs) -> + count_small(Cs, #{p => 0, s => 0, w => 0, other => 0}). + +count_small([#{control_char := $p}|Cs], #{p := P} = Cnts) -> + count_small(Cs, Cnts#{p := P + 1}); +count_small([#{control_char := $P}|Cs], #{p := P} = Cnts) -> + count_small(Cs, Cnts#{p := P + 1}); +count_small([#{control_char := $w}|Cs], #{w := W} = Cnts) -> + count_small(Cs, Cnts#{w := W + 1}); +count_small([#{control_char := $W}|Cs], #{w := W} = Cnts) -> + count_small(Cs, Cnts#{w := W + 1}); +count_small([#{control_char := $s}|Cs], #{w := W} = Cnts) -> + count_small(Cs, Cnts#{w := W + 1}); +count_small([S|Cs], #{other := Other} = Cnts) when is_list(S); + is_binary(S) -> + count_small(Cs, Cnts#{other := Other + string:length(S)}); +count_small([C|Cs], #{other := Other} = Cnts) when is_integer(C) -> + count_small(Cs, Cnts#{other := Other + 1}); +count_small([], #{p := P, s := S, w := W, other := Other}) -> + {P, S, W, Other}. + +%% build_small([Control]) -> io_lib:chars(). +%% Interpret the control structures, but only the small ones. +%% The big ones are saved for later. +%% build_limited([Control], NumberOfPps, NumberOfLimited, +%% CharsLimit, Indentation) %% Interpret the control structures. Count the number of print %% remaining and only calculate indentation when necessary. Must also %% be smart when calculating indentation for characters in format. -build([#{control_char := C, args := As, width := F, adjust := Ad, - precision := P, pad_char := Pad, encoding := Enc, - strings := Str} | Cs], Pc0, I) -> - S = control(C, As, F, Ad, P, Pad, Enc, Str, I), - Pc1 = decr_pc(C, Pc0), +build_small([#{control_char := C, args := As, width := F, adjust := Ad, + precision := P, pad_char := Pad, encoding := Enc}=CC | Cs]) -> + case control_small(C, As, F, Ad, P, Pad, Enc) of + not_small -> [CC | build_small(Cs)]; + S -> lists:flatten(S) ++ build_small(Cs) + end; +build_small([C|Cs]) -> [C|build_small(Cs)]; +build_small([]) -> []. + +build_limited([#{control_char := C, args := As, width := F, adjust := Ad, + precision := P, pad_char := Pad, encoding := Enc, + strings := Str} | Cs], NumOfPs0, Count0, MaxLen0, I) -> + MaxChars = if + MaxLen0 < 0 -> MaxLen0; + true -> MaxLen0 div Count0 + end, + S = control_limited(C, As, F, Ad, P, Pad, Enc, Str, MaxChars, I), + Len = string:length(S), + NumOfPs = decr_pc(C, NumOfPs0), + Count = Count0 - 1, + MaxLen = sub(MaxLen0, Len), if - Pc1 > 0 -> [S|build(Cs, Pc1, indentation(S, I))]; - true -> [S|build(Cs, Pc1, I)] + NumOfPs > 0 -> [S|build_limited(Cs, NumOfPs, Count, + MaxLen, indentation(S, I))]; + true -> [S|build_limited(Cs, NumOfPs, Count, MaxLen, I)] end; -build([$\n|Cs], Pc, _I) -> [$\n|build(Cs, Pc, 0)]; -build([$\t|Cs], Pc, I) -> [$\t|build(Cs, Pc, ((I + 8) div 8) * 8)]; -build([C|Cs], Pc, I) -> [C|build(Cs, Pc, I+1)]; -build([], _Pc, _I) -> []. +build_limited([$\n|Cs], NumOfPs, Count, MaxLen, _I) -> + [$\n|build_limited(Cs, NumOfPs, Count, MaxLen, 0)]; +build_limited([$\t|Cs], NumOfPs, Count, MaxLen, I) -> + [$\t|build_limited(Cs, NumOfPs, Count, MaxLen, ((I + 8) div 8) * 8)]; +build_limited([C|Cs], NumOfPs, Count, MaxLen, I) -> + [C|build_limited(Cs, NumOfPs, Count, MaxLen, I+1)]; +build_limited([], _, _, _, _) -> []. decr_pc($p, Pc) -> Pc - 1; decr_pc($P, Pc) -> Pc - 1; decr_pc(_, Pc) -> Pc. - %% Calculate the indentation of the end of a string given its start %% indentation. We assume tabs at 8 cols. @@ -252,64 +316,74 @@ indentation([C|Cs], I) -> indentation(Cs, indentation(C, I)); indentation([], I) -> I. -%% control(FormatChar, [Argument], FieldWidth, Adjust, Precision, PadChar, -%% Encoding, Indentation) -> String -%% This is the main dispatch function for the various formatting commands. -%% Field widths and precisions have already been calculated. - -control($w, [A], F, Adj, P, Pad, _Enc, _Str, _I) -> - term(io_lib:write(A, -1), F, Adj, P, Pad); -control($p, [A], F, Adj, P, Pad, Enc, Str, I) -> - print(A, -1, F, Adj, P, Pad, Enc, Str, I); -control($W, [A,Depth], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(Depth) -> - term(io_lib:write(A, Depth), F, Adj, P, Pad); -control($P, [A,Depth], F, Adj, P, Pad, Enc, Str, I) when is_integer(Depth) -> - print(A, Depth, F, Adj, P, Pad, Enc, Str, I); -control($s, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_atom(A) -> - string(atom_to_list(A), F, Adj, P, Pad); -control($s, [L0], F, Adj, P, Pad, latin1, _Str, _I) -> - L = iolist_to_chars(L0), +%% control_small(FormatChar, [Argument], FieldWidth, Adjust, Precision, +%% PadChar, Encoding) -> String +%% control_limited(FormatChar, [Argument], FieldWidth, Adjust, Precision, +%% PadChar, Encoding, StringP, ChrsLim, Indentation) -> String +%% These are the dispatch functions for the various formatting controls. + +control_small($s, [A], F, Adj, P, Pad, latin1) when is_atom(A) -> + L = iolist_to_chars(atom_to_list(A)), string(L, F, Adj, P, Pad); -control($s, [L0], F, Adj, P, Pad, unicode, _Str, _I) -> - L = cdata_to_chars(L0), - uniconv(string(L, F, Adj, P, Pad)); -control($e, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_float(A) -> +control_small($s, [A], F, Adj, P, Pad, unicode) when is_atom(A) -> + string(atom_to_list(A), F, Adj, P, Pad); +control_small($e, [A], F, Adj, P, Pad, _Enc) when is_float(A) -> fwrite_e(A, F, Adj, P, Pad); -control($f, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_float(A) -> +control_small($f, [A], F, Adj, P, Pad, _Enc) when is_float(A) -> fwrite_f(A, F, Adj, P, Pad); -control($g, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_float(A) -> +control_small($g, [A], F, Adj, P, Pad, _Enc) when is_float(A) -> fwrite_g(A, F, Adj, P, Pad); -control($b, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($b, [A], F, Adj, P, Pad, _Enc) when is_integer(A) -> unprefixed_integer(A, F, Adj, base(P), Pad, true); -control($B, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($B, [A], F, Adj, P, Pad, _Enc) when is_integer(A) -> unprefixed_integer(A, F, Adj, base(P), Pad, false); -control($x, [A,Prefix], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A), - is_atom(Prefix) -> +control_small($x, [A,Prefix], F, Adj, P, Pad, _Enc) when is_integer(A), + is_atom(Prefix) -> prefixed_integer(A, F, Adj, base(P), Pad, atom_to_list(Prefix), true); -control($x, [A,Prefix], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($x, [A,Prefix], F, Adj, P, Pad, _Enc) when is_integer(A) -> true = io_lib:deep_char_list(Prefix), %Check if Prefix a character list prefixed_integer(A, F, Adj, base(P), Pad, Prefix, true); -control($X, [A,Prefix], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A), - is_atom(Prefix) -> +control_small($X, [A,Prefix], F, Adj, P, Pad, _Enc) when is_integer(A), + is_atom(Prefix) -> prefixed_integer(A, F, Adj, base(P), Pad, atom_to_list(Prefix), false); -control($X, [A,Prefix], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($X, [A,Prefix], F, Adj, P, Pad, _Enc) when is_integer(A) -> true = io_lib:deep_char_list(Prefix), %Check if Prefix a character list prefixed_integer(A, F, Adj, base(P), Pad, Prefix, false); -control($+, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($+, [A], F, Adj, P, Pad, _Enc) when is_integer(A) -> Base = base(P), Prefix = [integer_to_list(Base), $#], prefixed_integer(A, F, Adj, Base, Pad, Prefix, true); -control($#, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($#, [A], F, Adj, P, Pad, _Enc) when is_integer(A) -> Base = base(P), Prefix = [integer_to_list(Base), $#], prefixed_integer(A, F, Adj, Base, Pad, Prefix, false); -control($c, [A], F, Adj, P, Pad, unicode, _Str, _I) when is_integer(A) -> +control_small($c, [A], F, Adj, P, Pad, unicode) when is_integer(A) -> char(A, F, Adj, P, Pad); -control($c, [A], F, Adj, P, Pad, _Enc, _Str, _I) when is_integer(A) -> +control_small($c, [A], F, Adj, P, Pad, _Enc) when is_integer(A) -> char(A band 255, F, Adj, P, Pad); -control($~, [], F, Adj, P, Pad, _Enc, _Str, _I) -> char($~, F, Adj, P, Pad); -control($n, [], F, Adj, P, Pad, _Enc, _Str, _I) -> newline(F, Adj, P, Pad); -control($i, [_A], _F, _Adj, _P, _Pad, _Enc, _Str, _I) -> []. +control_small($~, [], F, Adj, P, Pad, _Enc) -> char($~, F, Adj, P, Pad); +control_small($n, [], F, Adj, P, Pad, _Enc) -> newline(F, Adj, P, Pad); +control_small($i, [_A], _F, _Adj, _P, _Pad, _Enc) -> []; +control_small(_C, _As, _F, _Adj, _P, _Pad, _Enc) -> not_small. + +control_limited($s, [L0], F, Adj, P, Pad, latin1, _Str, CL, _I) -> + L = iolist_to_chars(L0), + string(limit_string(L, F, CL), limit_field(F, CL), Adj, P, Pad); +control_limited($s, [L0], F, Adj, P, Pad, unicode, _Str, CL, _I) -> + L = cdata_to_chars(L0), + uniconv(string(limit_string(L, F, CL), limit_field(F, CL), Adj, P, Pad)); +control_limited($w, [A], F, Adj, P, Pad, Enc, _Str, CL, _I) -> + Chars = io_lib:write(A, [{depth, -1}, {encoding, Enc}, {chars_limit, CL}]), + term(Chars, F, Adj, P, Pad); +control_limited($p, [A], F, Adj, P, Pad, Enc, Str, CL, I) -> + print(A, -1, F, Adj, P, Pad, Enc, Str, CL, I); +control_limited($W, [A,Depth], F, Adj, P, Pad, Enc, _Str, CL, _I) + when is_integer(Depth) -> + Chars = io_lib:write(A, [{depth, Depth}, {encoding, Enc}, {chars_limit, CL}]), + term(Chars, F, Adj, P, Pad); +control_limited($P, [A,Depth], F, Adj, P, Pad, Enc, Str, CL, I) + when is_integer(Depth) -> + print(A, Depth, F, Adj, P, Pad, Enc, Str, CL, I). -ifdef(UNICODE_AS_BINARIES). uniconv(C) -> @@ -332,7 +406,7 @@ base(B) when is_integer(B) -> term(T, none, _Adj, none, _Pad) -> T; term(T, none, Adj, P, Pad) -> term(T, P, Adj, P, Pad); term(T, F, Adj, P0, Pad) -> - L = lists:flatlength(T), + L = string:length(T), P = erlang:min(L, case P0 of none -> F; _ -> min(P0, F) end), if L > P -> @@ -343,14 +417,16 @@ term(T, F, Adj, P0, Pad) -> %% print(Term, Depth, Field, Adjust, Precision, PadChar, Encoding, %% Indentation) -%% Print a term. - -print(T, D, none, Adj, P, Pad, E, Str, I) -> - print(T, D, 80, Adj, P, Pad, E, Str, I); -print(T, D, F, Adj, none, Pad, E, Str, I) -> - print(T, D, F, Adj, I+1, Pad, E, Str, I); -print(T, D, F, right, P, _Pad, Enc, Str, _I) -> - Options = [{column, P}, +%% Print a term. Field width sets maximum line length, Precision sets +%% initial indentation. + +print(T, D, none, Adj, P, Pad, E, Str, ChLim, I) -> + print(T, D, 80, Adj, P, Pad, E, Str, ChLim, I); +print(T, D, F, Adj, none, Pad, E, Str, ChLim, I) -> + print(T, D, F, Adj, I+1, Pad, E, Str, ChLim, I); +print(T, D, F, right, P, _Pad, Enc, Str, ChLim, _I) -> + Options = [{chars_limit, ChLim}, + {column, P}, {line_length, F}, {depth, D}, {encoding, Enc}, @@ -376,7 +452,7 @@ float_e(_Fl, {Ds,E}, P) -> {Fs,false} -> [Fs|float_exp(E-1)] end. -%% float_man([Digit], Icount, Dcount) -> {[Chars],CarryFlag}. +%% float_man([Digit], Icount, Dcount) -> {[Char],CarryFlag}. %% Generate the characters in the mantissa from the digits with Icount %% characters before the '.' and Dcount decimals. Handle carry and let %% caller decide what to do at top. @@ -391,7 +467,7 @@ float_man([D|Ds], I, Dc) -> {Cs,false} -> {[D|Cs],false} end; float_man([], I, Dc) -> %Pad with 0's - {string:chars($0, I, [$.|string:chars($0, Dc)]),false}. + {lists:duplicate(I, $0) ++ [$.|lists:duplicate(Dc, $0)],false}. float_man([D|_], 0) when D >= $5 -> {[],true}; float_man([_|_], 0) -> {[],false}; @@ -401,7 +477,7 @@ float_man([D|Ds], Dc) -> {Cs,true} -> {[D+1|Cs],false}; {Cs,false} -> {[D|Cs],false} end; -float_man([], Dc) -> {string:chars($0, Dc),false}. %Pad with 0's +float_man([], Dc) -> {lists:duplicate(Dc, $0),false}. %Pad with 0's %% float_exp(Exponent) -> [Char]. %% Generate the exponent of a floating point number. Always include sign. @@ -425,7 +501,7 @@ fwrite_f(Fl, F, Adj, P, Pad) when P >= 1 -> float_f(Fl, Fd, P) when Fl < 0.0 -> [$-|float_f(-Fl, Fd, P)]; float_f(Fl, {Ds,E}, P) when E =< 0 -> - float_f(Fl, {string:chars($0, -E+1, Ds),1}, P); %Prepend enough 0's + float_f(Fl, {lists:duplicate(-E+1, $0)++Ds,1}, P); %Prepend enough 0's float_f(_Fl, {Ds,E}, P) -> case float_man(Ds, E, P) of {Fs,true} -> "1" ++ Fs; %Handle carry @@ -667,15 +743,27 @@ cdata_to_chars(B) when is_binary(B) -> _ -> binary_to_list(B) end. +limit_string(S, F, CharsLimit) when CharsLimit < 0; CharsLimit >= F -> S; +limit_string(S, _F, CharsLimit) -> + case string:length(S) =< CharsLimit of + true -> S; + false -> [string:slice(S, 0, sub(CharsLimit, 3)), "..."] + end. + +limit_field(F, CharsLimit) when CharsLimit < 0; F =:= none -> + F; +limit_field(F, CharsLimit) -> + max(3, min(F, CharsLimit)). + %% string(String, Field, Adjust, Precision, PadChar) string(S, none, _Adj, none, _Pad) -> S; string(S, F, Adj, none, Pad) -> - string_field(S, F, Adj, lists:flatlength(S), Pad); + string_field(S, F, Adj, string:length(S), Pad); string(S, none, _Adj, P, Pad) -> - string_field(S, P, left, lists:flatlength(S), Pad); + string_field(S, P, left, string:length(S), Pad); string(S, F, Adj, P, Pad) when F >= P -> - N = lists:flatlength(S), + N = string:length(S), if F > P -> if N > P -> adjust(flat_trunc(S, P), chars(Pad, F-P), Adj); @@ -745,20 +833,9 @@ adjust(Data, Pad, right) -> [Pad|Data]. %% Flatten and truncate a deep list to at most N elements. flat_trunc(List, N) when is_integer(N), N >= 0 -> - flat_trunc(List, N, [], []). - -flat_trunc(L, 0, _, R) when is_list(L) -> - lists:reverse(R); -flat_trunc([H|T], N, S, R) when is_list(H) -> - flat_trunc(H, N, [T|S], R); -flat_trunc([H|T], N, S, R) -> - flat_trunc(T, N-1, S, [H|R]); -flat_trunc([], N, [H|S], R) -> - flat_trunc(H, N, S, R); -flat_trunc([], _, [], R) -> - lists:reverse(R). + string:slice(List, 0, N). -%% A deep version of string:chars/2,3 +%% A deep version of lists:duplicate/2 chars(_C, 0) -> []; @@ -791,3 +868,15 @@ lowercase([H|T]) -> [H|lowercase(T)]; lowercase([]) -> []. + +%% Make sure T does change sign. +sub(T, _) when T < 0 -> T; +sub(T, E) when T >= E -> T - E; +sub(_, _) -> 0. + +get_option(Key, TupleList, Default) -> + case lists:keyfind(Key, 1, TupleList) of + false -> Default; + {Key, Value} -> Value; + _ -> Default + end. |