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-rw-r--r--lib/stdlib/src/string.erl71
1 files changed, 63 insertions, 8 deletions
diff --git a/lib/stdlib/src/string.erl b/lib/stdlib/src/string.erl
index 4fdfe99b66..a0fa60fbc7 100644
--- a/lib/stdlib/src/string.erl
+++ b/lib/stdlib/src/string.erl
@@ -61,6 +61,8 @@
next_codepoint/1, next_grapheme/1
]).
+-export([to_float/1, to_integer/1]).
+
%% Old (will be deprecated) lists/string API kept for backwards compability
-export([len/1, concat/2, % equal/2, (extended in the new api)
chr/2,rchr/2,str/2,rstr/2,
@@ -80,26 +82,28 @@
-type grapheme_cluster() :: char() | [char()].
-type direction() :: 'leading' | 'trailing'.
-%%% BIFs
--export([to_float/1, to_integer/1]).
-dialyzer({no_improper_lists, stack/2}).
+%%% BIFs internal (not documented) should not to be used outside of this module
+%%% May be removed
+-export([list_to_float/1, list_to_integer/1]).
--spec to_float(String) -> {Float, Rest} | {error, Reason} when
+%% Uses bifs: string:list_to_float/1 and string:list_to_integer/1
+-spec list_to_float(String) -> {Float, Rest} | {'error', Reason} when
String :: string(),
Float :: float(),
Rest :: string(),
- Reason :: no_float | not_a_list.
+ Reason :: 'no_float' | 'not_a_list'.
-to_float(_) ->
+list_to_float(_) ->
erlang:nif_error(undef).
--spec to_integer(String) -> {Int, Rest} | {error, Reason} when
+-spec list_to_integer(String) -> {Int, Rest} | {'error', Reason} when
String :: string(),
Int :: integer(),
Rest :: string(),
- Reason :: no_integer | not_a_list.
+ Reason :: 'no_integer' | 'not_a_list'.
-to_integer(_) ->
+list_to_integer(_) ->
erlang:nif_error(undef).
%%% End of BIFs
@@ -335,6 +339,57 @@ casefold(CD) when is_list(CD) ->
casefold(CD) when is_binary(CD) ->
casefold_bin(CD,<<>>).
+-spec to_integer(String) -> {Int, Rest} | {'error', Reason} when
+ String :: unicode:chardata(),
+ Int :: integer(),
+ Rest :: unicode:chardata(),
+ Reason :: 'no_integer' | badarg.
+
+to_integer(String) ->
+ try take(String, "+-0123456789") of
+ {Head, Tail} ->
+ case is_empty(Head) of
+ true -> {error, no_integer};
+ false ->
+ List = unicode:characters_to_list(Head),
+ case string:list_to_integer(List) of
+ {error, _} = Err -> Err;
+ {Int, Rest} ->
+ to_number(String, Int, Rest, List, Tail)
+ end
+ end
+ catch _:_ -> {error, badarg}
+ end.
+
+-spec to_float(String) -> {Float, Rest} | {'error', Reason} when
+ String :: unicode:chardata(),
+ Float :: float(),
+ Rest :: unicode:chardata(),
+ Reason :: 'no_float' | 'badarg'.
+
+to_float(String) ->
+ try take(String, "+-0123456789eE.,") of
+ {Head, Tail} ->
+ case is_empty(Head) of
+ true -> {error, no_float};
+ false ->
+ List = unicode:characters_to_list(Head),
+ case string:list_to_float(List) of
+ {error, _} = Err -> Err;
+ {Float, Rest} ->
+ to_number(String, Float, Rest, List, Tail)
+ end
+ end
+ catch _:_ -> {error, badarg}
+ end.
+
+to_number(String, Number, Rest, List, _Tail) when is_binary(String) ->
+ BSz = length(List)-length(Rest),
+ <<_:BSz/binary, Cont/binary>> = String,
+ {Number, Cont};
+to_number(_, Number, Rest, _, Tail) ->
+ {Number, concat(Rest,Tail)}.
+
%% Return the remaining string with prefix removed or else nomatch
-spec prefix(String::unicode:chardata(), Prefix::unicode:chardata()) ->
'nomatch' | unicode:chardata().