%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2016. 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.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(string).
-export([len/1,equal/2,concat/2,chr/2,rchr/2,str/2,rstr/2,
span/2,cspan/2,substr/2,substr/3,tokens/2,chars/2,chars/3]).
-export([copies/2,words/1,words/2,strip/1,strip/2,strip/3,
sub_word/2,sub_word/3,left/2,left/3,right/2,right/3,
sub_string/2,sub_string/3,centre/2,centre/3, join/2]).
-export([to_upper/1, to_lower/1]).
-import(lists,[reverse/1,member/2]).
%%---------------------------------------------------------------------------
%%% BIFs
-export([to_float/1, to_integer/1]).
-spec to_float(String) -> {Float, Rest} | {error, Reason} when
String :: string(),
Float :: float(),
Rest :: string(),
Reason :: no_float | not_a_list.
to_float(_) ->
erlang:nif_error(undef).
-spec to_integer(String) -> {Int, Rest} | {error, Reason} when
String :: string(),
Int :: integer(),
Rest :: string(),
Reason :: no_integer | not_a_list.
to_integer(_) ->
erlang:nif_error(undef).
%%% End of BIFs
%% Robert's bit
%% len(String)
%% Return the length of a string.
-spec len(String) -> Length when
String :: string(),
Length :: non_neg_integer().
len(S) -> length(S).
%% equal(String1, String2)
%% Test if 2 strings are equal.
-spec equal(String1, String2) -> boolean() when
String1 :: string(),
String2 :: string().
equal(S, S) -> true;
equal(_, _) -> false.
%% concat(String1, String2)
%% Concatenate 2 strings.
-spec concat(String1, String2) -> String3 when
String1 :: string(),
String2 :: string(),
String3 :: string().
concat(S1, S2) -> S1 ++ S2.
%% chr(String, Char)
%% rchr(String, Char)
%% Return the first/last index of the character in a string.
-spec chr(String, Character) -> Index when
String :: string(),
Character :: char(),
Index :: non_neg_integer().
chr(S, C) when is_integer(C) -> chr(S, C, 1).
chr([C|_Cs], C, I) -> I;
chr([_|Cs], C, I) -> chr(Cs, C, I+1);
chr([], _C, _I) -> 0.
-spec rchr(String, Character) -> Index when
String :: string(),
Character :: char(),
Index :: non_neg_integer().
rchr(S, C) when is_integer(C) -> rchr(S, C, 1, 0).
rchr([C|Cs], C, I, _L) -> %Found one, now find next!
rchr(Cs, C, I+1, I);
rchr([_|Cs], C, I, L) ->
rchr(Cs, C, I+1, L);
rchr([], _C, _I, L) -> L.
%% str(String, SubString)
%% rstr(String, SubString)
%% index(String, SubString)
%% Return the first/last index of the sub-string in a string.
%% index/2 is kept for backwards compatibility.
-spec str(String, SubString) -> Index when
String :: string(),
SubString :: string(),
Index :: non_neg_integer().
str(S, Sub) when is_list(Sub) -> str(S, Sub, 1).
str([C|S], [C|Sub], I) ->
case prefix(Sub, S) of
true -> I;
false -> str(S, [C|Sub], I+1)
end;
str([_|S], Sub, I) -> str(S, Sub, I+1);
str([], _Sub, _I) -> 0.
-spec rstr(String, SubString) -> Index when
String :: string(),
SubString :: string(),
Index :: non_neg_integer().
rstr(S, Sub) when is_list(Sub) -> rstr(S, Sub, 1, 0).
rstr([C|S], [C|Sub], I, L) ->
case prefix(Sub, S) of
true -> rstr(S, [C|Sub], I+1, I);
false -> rstr(S, [C|Sub], I+1, L)
end;
rstr([_|S], Sub, I, L) -> rstr(S, Sub, I+1, L);
rstr([], _Sub, _I, L) -> L.
prefix([C|Pre], [C|String]) -> prefix(Pre, String);
prefix([], String) when is_list(String) -> true;
prefix(Pre, String) when is_list(Pre), is_list(String) -> false.
%% span(String, Chars) -> Length.
%% cspan(String, Chars) -> Length.
-spec span(String, Chars) -> Length when
String :: string(),
Chars :: string(),
Length :: non_neg_integer().
span(S, Cs) when is_list(Cs) -> span(S, Cs, 0).
span([C|S], Cs, I) ->
case member(C, Cs) of
true -> span(S, Cs, I+1);
false -> I
end;
span([], _Cs, I) -> I.
-spec cspan(String, Chars) -> Length when
String :: string(),
Chars :: string(),
Length :: non_neg_integer().
cspan(S, Cs) when is_list(Cs) -> cspan(S, Cs, 0).
cspan([C|S], Cs, I) ->
case member(C, Cs) of
true -> I;
false -> cspan(S, Cs, I+1)
end;
cspan([], _Cs, I) -> I.
%% substr(String, Start)
%% substr(String, Start, Length)
%% Extract a sub-string from String.
-spec substr(String, Start) -> SubString when
String :: string(),
SubString :: string(),
Start :: pos_integer().
substr(String, 1) when is_list(String) ->
String;
substr(String, S) when is_integer(S), S > 1 ->
substr2(String, S).
-spec substr(String, Start, Length) -> SubString when
String :: string(),
SubString :: string(),
Start :: pos_integer(),
Length :: non_neg_integer().
substr(String, S, L) when is_integer(S), S >= 1, is_integer(L), L >= 0 ->
substr1(substr2(String, S), L).
substr1([C|String], L) when L > 0 -> [C|substr1(String, L-1)];
substr1(String, _L) when is_list(String) -> []. %Be nice!
substr2(String, 1) when is_list(String) -> String;
substr2([_|String], S) -> substr2(String, S-1).
%% tokens(String, Seperators).
%% Return a list of tokens seperated by characters in Seperators.
-spec tokens(String, SeparatorList) -> Tokens when
String :: string(),
SeparatorList :: string(),
Tokens :: [Token :: nonempty_string()].
tokens(S, Seps) ->
case Seps of
[] ->
case S of
[] -> [];
[_|_] -> [S]
end;
[C] ->
tokens_single_1(reverse(S), C, []);
[_|_] ->
tokens_multiple_1(reverse(S), Seps, [])
end.
tokens_single_1([Sep|S], Sep, Toks) ->
tokens_single_1(S, Sep, Toks);
tokens_single_1([C|S], Sep, Toks) ->
tokens_single_2(S, Sep, Toks, [C]);
tokens_single_1([], _, Toks) ->
Toks.
tokens_single_2([Sep|S], Sep, Toks, Tok) ->
tokens_single_1(S, Sep, [Tok|Toks]);
tokens_single_2([C|S], Sep, Toks, Tok) ->
tokens_single_2(S, Sep, Toks, [C|Tok]);
tokens_single_2([], _Sep, Toks, Tok) ->
[Tok|Toks].
tokens_multiple_1([C|S], Seps, Toks) ->
case member(C, Seps) of
true -> tokens_multiple_1(S, Seps, Toks);
false -> tokens_multiple_2(S, Seps, Toks, [C])
end;
tokens_multiple_1([], _Seps, Toks) ->
Toks.
tokens_multiple_2([C|S], Seps, Toks, Tok) ->
case member(C, Seps) of
true -> tokens_multiple_1(S, Seps, [Tok|Toks]);
false -> tokens_multiple_2(S, Seps, Toks, [C|Tok])
end;
tokens_multiple_2([], _Seps, Toks, Tok) ->
[Tok|Toks].
-spec chars(Character, Number) -> String when
Character :: char(),
Number :: non_neg_integer(),
String :: string().
chars(C, N) -> chars(C, N, []).
-spec chars(Character, Number, Tail) -> String when
Character :: char(),
Number :: non_neg_integer(),
Tail :: string(),
String :: string().
chars(C, N, Tail) when N > 0 ->
chars(C, N-1, [C|Tail]);
chars(C, 0, Tail) when is_integer(C) ->
Tail.
%% Torbjörn's bit.
%%% COPIES %%%
-spec copies(String, Number) -> Copies when
String :: string(),
Copies :: string(),
Number :: non_neg_integer().
copies(CharList, Num) when is_list(CharList), is_integer(Num), Num >= 0 ->
copies(CharList, Num, []).
copies(_CharList, 0, R) ->
R;
copies(CharList, Num, R) ->
copies(CharList, Num-1, CharList++R).
%%% WORDS %%%
-spec words(String) -> Count when
String :: string(),
Count :: pos_integer().
words(String) -> words(String, $\s).
-spec words(String, Character) -> Count when
String :: string(),
Character :: char(),
Count :: pos_integer().
words(String, Char) when is_integer(Char) ->
w_count(strip(String, both, Char), Char, 0).
w_count([], _, Num) -> Num+1;
w_count([H|T], H, Num) -> w_count(strip(T, left, H), H, Num+1);
w_count([_H|T], Char, Num) -> w_count(T, Char, Num).
%%% SUB_WORDS %%%
-spec sub_word(String, Number) -> Word when
String :: string(),
Word :: string(),
Number :: integer().
sub_word(String, Index) -> sub_word(String, Index, $\s).
-spec sub_word(String, Number, Character) -> Word when
String :: string(),
Word :: string(),
Number :: integer(),
Character :: char().
sub_word(String, Index, Char) when is_integer(Index), is_integer(Char) ->
case words(String, Char) of
Num when Num < Index ->
[];
_Num ->
s_word(strip(String, left, Char), Index, Char, 1, [])
end.
s_word([], _, _, _,Res) -> reverse(Res);
s_word([Char|_],Index,Char,Index,Res) -> reverse(Res);
s_word([H|T],Index,Char,Index,Res) -> s_word(T,Index,Char,Index,[H|Res]);
s_word([Char|T],Stop,Char,Index,Res) when Index < Stop ->
s_word(strip(T,left,Char),Stop,Char,Index+1,Res);
s_word([_|T],Stop,Char,Index,Res) when Index < Stop ->
s_word(T,Stop,Char,Index,Res).
%%% STRIP %%%
-spec strip(string()) -> string().
strip(String) -> strip(String, both).
-spec strip(String, Direction) -> Stripped when
String :: string(),
Stripped :: string(),
Direction :: left | right | both.
strip(String, left) -> strip_left(String, $\s);
strip(String, right) -> strip_right(String, $\s);
strip(String, both) ->
strip_right(strip_left(String, $\s), $\s).
-spec strip(String, Direction, Character) -> Stripped when
String :: string(),
Stripped :: string(),
Direction :: left | right | both,
Character :: char().
strip(String, right, Char) -> strip_right(String, Char);
strip(String, left, Char) -> strip_left(String, Char);
strip(String, both, Char) ->
strip_right(strip_left(String, Char), Char).
strip_left([Sc|S], Sc) ->
strip_left(S, Sc);
strip_left([_|_]=S, Sc) when is_integer(Sc) -> S;
strip_left([], Sc) when is_integer(Sc) -> [].
strip_right([Sc|S], Sc) ->
case strip_right(S, Sc) of
[] -> [];
T -> [Sc|T]
end;
strip_right([C|S], Sc) ->
[C|strip_right(S, Sc)];
strip_right([], Sc) when is_integer(Sc) ->
[].
%%% LEFT %%%
-spec left(String, Number) -> Left when
String :: string(),
Left :: string(),
Number :: non_neg_integer().
left(String, Len) when is_integer(Len) -> left(String, Len, $\s).
-spec left(String, Number, Character) -> Left when
String :: string(),
Left :: string(),
Number :: non_neg_integer(),
Character :: char().
left(String, Len, Char) when is_integer(Char) ->
Slen = length(String),
if
Slen > Len -> substr(String, 1, Len);
Slen < Len -> l_pad(String, Len-Slen, Char);
Slen =:= Len -> String
end.
l_pad(String, Num, Char) -> String ++ chars(Char, Num).
%%% RIGHT %%%
-spec right(String, Number) -> Right when
String :: string(),
Right :: string(),
Number :: non_neg_integer().
right(String, Len) when is_integer(Len) -> right(String, Len, $\s).
-spec right(String, Number, Character) -> Right when
String :: string(),
Right :: string(),
Number :: non_neg_integer(),
Character :: char().
right(String, Len, Char) when is_integer(Char) ->
Slen = length(String),
if
Slen > Len -> substr(String, Slen-Len+1);
Slen < Len -> r_pad(String, Len-Slen, Char);
Slen =:= Len -> String
end.
r_pad(String, Num, Char) -> chars(Char, Num, String).
%%% CENTRE %%%
-spec centre(String, Number) -> Centered when
String :: string(),
Centered :: string(),
Number :: non_neg_integer().
centre(String, Len) when is_integer(Len) -> centre(String, Len, $\s).
-spec centre(String, Number, Character) -> Centered when
String :: string(),
Centered :: string(),
Number :: non_neg_integer(),
Character :: char().
centre(String, 0, Char) when is_list(String), is_integer(Char) ->
[]; % Strange cases to centre string
centre(String, Len, Char) when is_integer(Char) ->
Slen = length(String),
if
Slen > Len -> substr(String, (Slen-Len) div 2 + 1, Len);
Slen < Len ->
N = (Len-Slen) div 2,
r_pad(l_pad(String, Len-(Slen+N), Char), N, Char);
Slen =:= Len -> String
end.
%%% SUB_STRING %%%
-spec sub_string(String, Start) -> SubString when
String :: string(),
SubString :: string(),
Start :: pos_integer().
sub_string(String, Start) -> substr(String, Start).
-spec sub_string(String, Start, Stop) -> SubString when
String :: string(),
SubString :: string(),
Start :: pos_integer(),
Stop :: pos_integer().
sub_string(String, Start, Stop) -> substr(String, Start, Stop - Start + 1).
%% ISO/IEC 8859-1 (latin1) letters are converted, others are ignored
%%
to_lower_char(C) when is_integer(C), $A =< C, C =< $Z ->
C + 32;
to_lower_char(C) when is_integer(C), 16#C0 =< C, C =< 16#D6 ->
C + 32;
to_lower_char(C) when is_integer(C), 16#D8 =< C, C =< 16#DE ->
C + 32;
to_lower_char(C) ->
C.
to_upper_char(C) when is_integer(C), $a =< C, C =< $z ->
C - 32;
to_upper_char(C) when is_integer(C), 16#E0 =< C, C =< 16#F6 ->
C - 32;
to_upper_char(C) when is_integer(C), 16#F8 =< C, C =< 16#FE ->
C - 32;
to_upper_char(C) ->
C.
-spec to_lower(String) -> Result when
String :: io_lib:latin1_string(),
Result :: io_lib:latin1_string()
; (Char) -> CharResult when
Char :: char(),
CharResult :: char().
to_lower(S) when is_list(S) ->
[to_lower_char(C) || C <- S];
to_lower(C) when is_integer(C) ->
to_lower_char(C).
-spec to_upper(String) -> Result when
String :: io_lib:latin1_string(),
Result :: io_lib:latin1_string()
; (Char) -> CharResult when
Char :: char(),
CharResult :: char().
to_upper(S) when is_list(S) ->
[to_upper_char(C) || C <- S];
to_upper(C) when is_integer(C) ->
to_upper_char(C).
-spec join(StringList, Separator) -> String when
StringList :: [string()],
Separator :: string(),
String :: string().
join([], Sep) when is_list(Sep) ->
[];
join([H|T], Sep) ->
H ++ lists:append([Sep ++ X || X <- T]).
