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Diffstat (limited to 'lib/stdlib/src/io_lib_fread.erl')
| -rw-r--r-- | lib/stdlib/src/io_lib_fread.erl | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/lib/stdlib/src/io_lib_fread.erl b/lib/stdlib/src/io_lib_fread.erl new file mode 100644 index 0000000000..74316dc730 --- /dev/null +++ b/lib/stdlib/src/io_lib_fread.erl @@ -0,0 +1,466 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1996-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% +-module(io_lib_fread). + +%% Formatted input functions of io library. + +-export([fread/2,fread/3]). + +-import(lists, [reverse/1,reverse/2]). + +%%----------------------------------------------------------------------- +%% Local types +%%----------------------------------------------------------------------- + +-type done_arg2() :: {'ok', io_lib:chars()} | 'eof' | {'error', term()}. + +%%----------------------------------------------------------------------- +%% Types also used in other files +%%----------------------------------------------------------------------- + +-type continuation() :: [] | {_, _, _, _}. % XXX: refine + +-type fread_2_ret() :: {'ok', io_lib:chars(), string()} + | {'more', string(), non_neg_integer(), io_lib:chars()} + | {'error', term()}. +-type fread_3_ret() :: {'more', continuation()} + | {'done', done_arg2(), string()}. + +%%----------------------------------------------------------------------- + +%% fread(Continuation, CharList, FormatString) +%% This is the main function into the re-entrant formatted reader. It +%% repeatedly collects lines and calls fread/2 to format the input until +%% all the format string has been used. And it counts the characters. + +-spec fread(io_lib_fread:continuation(), string(), string()) -> fread_3_ret(). + +fread([], Chars, Format) -> + %%io:format("FREAD: ~w `~s'~n", [Format,Chars]), + fread_collect(Format, [], 0, [], Chars); +fread({Format,Stack,N,Results}=_Continuation, Chars, _) -> + %%io:format("FREAD: ~w `~s'~n", [_Continuation,Chars]), + fread_collect(Format, Stack, N, Results, Chars). + +fread_collect(Format, [$\r|Stack], N, Results, [$\n|Chars]) -> + fread_line(Format, reverse(Stack), N, Results, Chars, [$\r,$\n]); +fread_collect(Format, Stack, N, Results, [$\n|Chars]) -> + fread_line(Format, reverse(Stack), N, Results, Chars, [$\n]); +fread_collect(Format, Stack, N, Results, []) -> + Continuation = {Format,Stack,N,Results}, + {more,Continuation}; +fread_collect(Format, [$\r|Stack], N, Results, Chars) -> % Maybe eof + fread_line(Format, reverse(Stack), N, Results, Chars, [$\r]); +fread_collect(Format, Stack, N, Results, [C|Chars]) -> + fread_collect(Format, [C|Stack], N, Results, Chars); +fread_collect(Format, Stack, N, Results, Chars) -> % eof + fread_line(Format, reverse(Stack), N, Results, Chars, []). + +fread_line(Format0, Line, N0, Results0, More, Newline) -> + %%io:format("FREAD1: `~s' `~s'~n", [Format0,Line]), + Chars = if is_list(More) -> More; true -> [] end, + case fread(Format0, Line, N0, Results0) of + {ok,Results,[]} -> + {done,{ok,Results},Chars}; + {ok,Results,Rest} -> + %% Don't lose the whitespace + {done,{ok,Results},Rest++(Newline++Chars)}; + %% fread/4 should not return {more,...} on eof; guard just in case... + %% Count newline characters here since fread/4 does not get them. + {more,Format,N,Results} when is_list(Line), is_list(More) -> + fread_collect(Format, [], N+length(Newline), Results, More); + {more,Format,N,Results} when is_list(Line) -> % eof + fread_line(Format, eof, N+length(Newline), Results, More, []); + Other -> %An error has occurred + {done,Other,More} + end. + + +%% Conventions +%% ~s String White terminated +%% ~d Integer terminated by ~[0-9] +%% ~u Unsigned integer in base 2..36, no leading whitespace +%% ~- Optional sign character, no leading whitespace +%% ~f Float +%% ~a as ~s but converted to an atom +%% ~c characters without any stripping +%% ~n number of characters scanned +%% WHITE Skip white space +%% X Literal X + +-spec fread(string(), string()) -> fread_2_ret(). + +fread(Format, Line) -> + fread(Format, Line, 0, []). + +fread([$~|Format0], Line, N, Results) -> + {Format,F,Sup,Unicode} = fread_field(Format0), + fread1(Format, F, Sup, Unicode, Line, N, Results, Format0); +fread([$\s|Format], Line, N, Results) -> + fread_skip_white(Format, Line, N, Results); +fread([$\t|Format], Line, N, Results) -> + fread_skip_white(Format, Line, N, Results); +fread([$\r|Format], Line, N, Results) -> + fread_skip_white(Format, Line, N, Results); +fread([$\n|Format], Line, N, Results) -> + fread_skip_white(Format, Line, N, Results); +fread([C|Format], [C|Line], N, Results) -> + fread(Format, Line, N+1, Results); +fread([_F|_Format], [_C|_Line], _N, _Results) -> + fread_error(input); +fread([], Line, _N, Results) -> + {ok,reverse(Results),Line}. + +fread_skip_white(Format, [$\s|Line], N, Results) -> + fread_skip_white(Format, Line, N+1, Results); +fread_skip_white(Format, [$\t|Line], N, Results) -> + fread_skip_white(Format, Line, N+1, Results); +fread_skip_white(Format, [$\r|Line], N, Results) -> + fread_skip_white(Format, Line, N+1, Results); +fread_skip_white(Format, [$\n|Line], N, Results) -> + fread_skip_white(Format, Line, N+1, Results); +fread_skip_white(Format, Line, N, Results) -> + fread(Format, Line, N, Results). + +%% fread_field(Format) +%% Reads the field specification paramters. Returns: +%% +%% {RestFormat,FieldWidth,Suppress} + +fread_field([$*|Format]) -> fread_field(Format, true, false); +fread_field(Format) -> fread_field(Format, false, false). + +fread_field([C|Format], Sup, Unic) when C >= $0, C =< $9 -> + fread_field(Format, C - $0, Sup, Unic); +fread_field([$t|Format], Sup, _Unic) -> + {Format,none,Sup,true}; +fread_field(Format, Sup, Unic) -> + {Format,none,Sup,Unic}. + +fread_field([C|Format], F, Sup, Unic) when C >= $0, C =< $9 -> + fread_field(Format, 10*F + C - $0, Sup, Unic); +fread_field([$t|Format], F, Sup, _Unic) -> + {Format,F,Sup,true}; +fread_field(Format, F, Sup, Unic) -> + {Format,F,Sup,Unic}. + +%% fread1(Format, FieldWidth, Suppress, Line, N, Results, AllFormat) +%% fread1(Format, FieldWidth, Suppress, Line, N, Results) +%% The main dispatch function for the formatting commands. Done in two +%% stages so format commands that need no input can always be processed. + +fread1([$l|Format], _F, Sup, _U, Line, N, Res, _AllFormat) -> + fread(Format, Line, N, fread_result(Sup, N, Res)); +fread1(_Format, _F, _Sup, _U, [], N, Res, AllFormat) -> + %% Need more input here. + {more,[$~|AllFormat],N,Res}; +fread1(_Format, _F, _Sup, _U, eof, _N, [], _AllFormat) -> + %% This is at start of format string so no error. + eof; +fread1(_Format, _F, _Sup, _U, eof, _N, _Res, _AllFormat) -> + %% This is an error as there is no more input. + fread_error(input); +fread1(Format, F, Sup, U, Line, N, Res, _AllFormat) -> + fread1(Format, F, Sup, U, Line, N, Res). + +fread1([$f|Format], none, Sup, false, Line0, N0, Res) -> + {Line,N,Cs} = fread_float_cs(Line0, N0), + fread_float(Cs, Sup, Format, Line, N, Res); +fread1([$f|Format], F, Sup, false, Line0, N, Res) -> + {Line,Cs} = fread_chars(Line0, F, false), + fread_float(Cs, Sup, Format, Line, N+F, Res); +fread1([$d|Format], none, Sup, false, Line0, N0, Res) -> + {Line,N,Cs} = fread_int_cs(Line0, N0), + fread_integer(Cs, 10, Sup, Format, Line, N, Res); +fread1([$d|Format], F, Sup, false, Line0, N, Res) -> + {Line,Cs} = fread_chars(Line0, F, false), + fread_integer(Cs, 10, Sup, Format, Line, N+F, Res); +fread1([$u|Format], none, Sup, false, Line0, N0, Res) -> + {Line,N,Cs} = fread_digits(Line0, N0, 10, []), + fread_unsigned(Cs, 10, Sup, Format, Line, N, Res); +fread1([$u|Format], F, Sup, false, Line0, N0, Res) when F >= 2, F =< 1+$Z-$A+10 -> + {Line,N,Cs} = fread_digits(Line0, N0, F, []), + fread_unsigned(Cs, F, Sup, Format, Line, N, Res); +fread1([$-|Format], _F, Sup, false, Line, N, Res) -> + fread_sign_char(Sup, Format, Line, N, Res); +fread1([$#|Format], none, Sup, false, Line0, N0, Res) -> + case catch + begin + {Line1,N1,B1} = fread_base(Line0, N0), + B = abs(B1), + true = (B >= 2) and (B =< 1+$Z-$A+10), + {Line2,N2,Cs2} = fread_digits(Line1, N1, B, []), + fread_based(reverse(Cs2), B1, Sup, Format, Line2, N2, Res) + end of + {'EXIT',_} -> + fread_error(based); + Other -> + Other + end; +fread1([$#|Format], F, Sup, false, Line0, N, Res) -> + case catch + begin + {Line1,Cs1} = fread_chars(Line0, F, false), + {Line2,_,B2} = fread_base(reverse(Cs1), N), + true = ((B2 >= 2) and (B2 =< 1+$Z-$A+10)), + fread_based(Line2, B2, Sup, Format, Line1, N+F, Res) + end of + {'EXIT',_} -> + fread_error(based); + Other -> + Other + end; +fread1([$s|Format], none, Sup, U, Line0, N0, Res) -> + {Line,N,Cs} = fread_string_cs(Line0, N0, U), + fread_string(Cs, Sup, U, Format, Line, N, Res); +fread1([$s|Format], F, Sup, U, Line0, N, Res) -> + {Line,Cs} = fread_chars(Line0, F, U), + fread_string(Cs, Sup, U, Format, Line, N+F, Res); +%% XXX:PaN Atoms still only latin1... +fread1([$a|Format], none, Sup, false, Line0, N0, Res) -> + {Line,N,Cs} = fread_string_cs(Line0, N0, false), + fread_atom(Cs, Sup, Format, Line, N, Res); +fread1([$a|Format], F, Sup, false, Line0, N, Res) -> + {Line,Cs} = fread_chars(Line0, F, false), + fread_atom(Cs, Sup, Format, Line, N+F, Res); +fread1([$c|Format], none, Sup, U, Line0, N, Res) -> + {Line,Cs} = fread_chars(Line0, 1, U), + fread_chars(Cs, Sup, U, Format, Line, N+1, Res); +fread1([$c|Format], F, Sup, U, Line0, N, Res) -> + {Line,Cs} = fread_chars(Line0, F, U), + fread_chars(Cs, Sup, U, Format, Line, N+F, Res); +fread1([$~|Format], _F, _Sup, _U, [$~|Line], N, Res) -> + fread(Format, Line, N+1, Res); +fread1(_Format, _F, _Sup, _U, _Line, _N, _Res) -> + fread_error(format). + +%% fread_float(FloatChars, Suppress, Format, Line, N, Results) + +fread_float(Cs, Sup, Format, Line, N, Res) -> + case catch list_to_float(fread_skip_white(reverse(Cs))) of + {'EXIT',_} -> + fread_error(float); + Float -> + fread(Format, Line, N, fread_result(Sup, Float, Res)) + end. + +%% fread_integer(IntegerChars, Base, Suppress, Format, Line, N, Results) + +fread_integer(Cs, Base, Sup, Format, Line, N, Res) -> + case catch erlang:list_to_integer(fread_skip_white(reverse(Cs)), Base) of + {'EXIT',_} -> + fread_error(integer); + Integer -> + fread(Format, Line, N, fread_result(Sup, Integer, Res)) + end. + + +%% fread_unsigned(IntegerChars, Base, Suppress, Format, Line, N, Results) + +fread_unsigned(Cs, Base, Sup, Format, Line, N, Res) -> + case catch erlang:list_to_integer(fread_skip_white(reverse(Cs)), Base) of + {'EXIT',_} -> + fread_error(unsigned); + Integer -> + fread(Format, Line, N, fread_result(Sup, Integer, Res)) + end. + + +%% fread_based(IntegerChars, Base, Suppress, Format, Line, N, Results) + +fread_based(Cs0, B, Sup, Format, Line, N, Res) -> + {Cs,Base} = if B < 0 -> {[$-|Cs0],-B}; + true -> {Cs0,B} + end, + I = erlang:list_to_integer(Cs, Base), + fread(Format, Line, N, fread_result(Sup, I, Res)). + + +%% fread_sign_char(Suppress, Format, Line, N, Results) + +fread_sign_char(Sup, Format, [$-|Line], N, Res) -> + fread(Format, Line, N+1, fread_result(Sup, -1, Res)); +fread_sign_char(Sup, Format, [$+|Line], N, Res) -> + fread(Format, Line, N+1, fread_result(Sup, +1, Res)); +fread_sign_char(Sup, Format, Line, N, Res) -> + fread(Format, Line, N, fread_result(Sup, 1, Res)). + + +%% fread_string(StringChars, Suppress, Format, Line, N, Results) + +fread_string(error, _Sup, _U, _Format, _Line, _N, _Res) -> + fread_error(string); +fread_string(Cs0, Sup, U, Format, Line, N, Res) -> + Cs = fread_skip_white(reverse(fread_skip_white(Cs0))), + fread(Format, Line, N, fread_convert(fread_result(Sup, Cs, Res),U)). + +%% fread_atom(AtomChars, Suppress, Format, Line, N, Results) + +fread_atom(error, _Sup, _Format, _Line, _N, _Res) -> + fread_error(atom); +fread_atom(Cs0, Sup, Format, Line, N, Res) -> + Cs = fread_skip_white(reverse(fread_skip_white(Cs0))), + fread(Format, Line, N, fread_result(Sup, list_to_atom(Cs), Res)). + +%% fread_chars(Characters, Suppress, Format, Line, N, Results) + +fread_chars(error, _Sup, _U, _Format, _Line, _N, _Res) -> + fread_error(character); +fread_chars(Cs, Sup, U, Format, Line, N, Res) -> + fread(Format, Line, N, fread_convert(fread_result(Sup, reverse(Cs), Res),U)). + +%% fread_chars(Line, Count) + +fread_chars(Line, C, U) -> + fread_chars(C, Line, U, []). + +fread_chars(0, Line, _U, Cs) -> {Line,Cs}; +fread_chars(_N, [$\n|Line], _U, _Cs) -> {[$\n|Line],error}; +fread_chars(N, [C|Line], true, Cs) -> + fread_chars(N-1, Line, true, [C|Cs]); +fread_chars(N, [C|Line], false, Cs) when C >= 0, C =< 255 -> + fread_chars(N-1, Line, false, [C|Cs]); +fread_chars(_N, L, _U, _Cs) -> + {L,error}. +%%fread_chars(_N, [], _U,_Cs) -> +%% {[],error}. + +%% fread_int_cs(Line, N) + +fread_int_cs(Line0, N0) -> + {Line1,N1} = fread_skip_white(Line0, N0), + {Line,N,Cs} = fread_sign(Line1, N1, []), + fread_digits(Line, N, Cs). + +%% fread_float_cs(Line, N) +%% A float is "[+|-][0-9]+.[0-9]+[[E|e][+|-][09-]+] + +fread_float_cs(Line0, N0) -> + {Line1,N1} = fread_skip_white(Line0, N0), + {Line2,N2,Cs2} = fread_sign(Line1, N1, []), + {Line,N,Cs} = fread_digits(Line2, N2, Cs2), + fread_float_cs_1(Line, N, Cs). + +fread_float_cs_1([$.|Line0], N0, Cs0) -> + {Line,N,Cs} = fread_digits(Line0, N0+1, [$.|Cs0]), + fread_float_cs_2(Line, N, Cs); +fread_float_cs_1(Line, N, Cs) -> + {Line,N,Cs}. + +fread_float_cs_2([$e|Line0], N0, Cs0) -> + {Line,N,Cs} = fread_sign(Line0, N0+1, [$e|Cs0]), + fread_digits(Line, N, Cs); +fread_float_cs_2([$E|Line0], N0, Cs0) -> + {Line,N,Cs} = fread_sign(Line0, N0+1, [$E|Cs0]), + fread_digits(Line, N, Cs); +fread_float_cs_2(Line, N, Cs) -> + {Line,N,Cs}. + +%% fread_string_cs(Line, N, Unicode) + +fread_string_cs(Line0, N0, false) -> + {Line,N} = fread_skip_white(Line0, N0), + fread_skip_latin1_nonwhite(Line, N, []); +fread_string_cs(Line0, N0, true) -> + {Line,N} = fread_skip_white(Line0, N0), + fread_skip_nonwhite(Line, N, []). + +%% fread_skip_white(Line) +%% fread_skip_white(Line, N) +%% fread_skip_nonwhite(Line, N, Characters) +%% fread_sign(Line, N, Characters) +%% fread_digits(Line, N, Characters) +%% fread_digits(Line, N, Base, Characters) +%% Read segments of things, return "thing" characters in reverse order. + +fread_skip_white([$\s|Line]) -> fread_skip_white(Line); +fread_skip_white([$\t|Line]) -> fread_skip_white(Line); +fread_skip_white([$\r|Line]) -> fread_skip_white(Line); +fread_skip_white([$\n|Line]) -> fread_skip_white(Line); +fread_skip_white(Line) -> Line. + +fread_skip_white([$\s|Line], N) -> + fread_skip_white(Line, N+1); +fread_skip_white([$\t|Line], N) -> + fread_skip_white(Line, N+1); +fread_skip_white([$\r|Line], N) -> + fread_skip_white(Line, N+1); +fread_skip_white([$\n|Line], N) -> + fread_skip_white(Line, N+1); +fread_skip_white(Line, N) -> {Line,N}. + +fread_skip_latin1_nonwhite([$\s|Line], N, Cs) -> {[$\s|Line],N,Cs}; +fread_skip_latin1_nonwhite([$\t|Line], N, Cs) -> {[$\t|Line],N,Cs}; +fread_skip_latin1_nonwhite([$\r|Line], N, Cs) -> {[$\r|Line],N,Cs}; +fread_skip_latin1_nonwhite([$\n|Line], N, Cs) -> {[$\n|Line],N,Cs}; +fread_skip_latin1_nonwhite([C|Line], N, []) when C > 255 -> + {[C|Line],N,error}; +fread_skip_latin1_nonwhite([C|Line], N, Cs) when C > 255 -> + {[C|Line],N,Cs}; +fread_skip_latin1_nonwhite([C|Line], N, Cs) -> + fread_skip_latin1_nonwhite(Line, N+1, [C|Cs]); +fread_skip_latin1_nonwhite([], N, Cs) -> {[],N,Cs}. + +fread_skip_nonwhite([$\s|Line], N, Cs) -> {[$\s|Line],N,Cs}; +fread_skip_nonwhite([$\t|Line], N, Cs) -> {[$\t|Line],N,Cs}; +fread_skip_nonwhite([$\r|Line], N, Cs) -> {[$\r|Line],N,Cs}; +fread_skip_nonwhite([$\n|Line], N, Cs) -> {[$\n|Line],N,Cs}; +fread_skip_nonwhite([C|Line], N, Cs) -> + fread_skip_nonwhite(Line, N+1, [C|Cs]); +fread_skip_nonwhite([], N, Cs) -> {[],N,Cs}. + +fread_sign([$+|Line], N, Cs) -> {Line,N+1,[$+|Cs]}; +fread_sign([$-|Line], N, Cs) -> {Line,N+1,[$-|Cs]}; +fread_sign(Line, N, Cs) -> {Line,N,Cs}. + +fread_base(Line0, N0) -> + {[$#|Line1],N1,Cs1} = fread_int_cs(Line0, N0), + B = list_to_integer(reverse(Cs1)), + {Line1,N1+1,B}. + +fread_digits([C|Line], N, Cs) when C >= $0, C =< $9 -> + fread_digits(Line, N+1, [C|Cs]); +fread_digits(Line, N, Cs) -> {Line,N,Cs}. + +fread_digits([C|Line], N, Base, Cs) when C >= $0, C =< $9 -> + fread_digits(Line, N+1, Base, [C|Cs]); +fread_digits([C|Line], N, Base, Cs) when C >= $A, C < $A+Base-10 -> + fread_digits(Line, N+1, Base, [C|Cs]); +fread_digits([C|Line], N, Base, Cs) when C >= $a, C < $a+Base-10 -> + fread_digits(Line, N+1, Base, [C|Cs]); +fread_digits(Line, N, _Base, Cs) -> {Line,N,Cs}. + + + +%% fread_result(Suppress, Value, Results) + +fread_result(true, _V, Res) -> Res; +fread_result(false, V, Res) -> [V|Res]. + +-ifdef(UNICODE_AS_BINARIES). +fread_convert([L|R],true) when is_list(L) -> + [unicode:characters_to_binary(L) | R]; +fread_convert(Any,_) -> + Any. +-else. +fread_convert(Any,_) -> + Any. +-endif. +fread_error(In) -> + {error,{fread,In}}. |