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author | Dan Gudmundsson <[email protected]> | 2017-02-28 15:23:11 +0100 |
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committer | Dan Gudmundsson <[email protected]> | 2017-04-24 12:16:56 +0200 |
commit | a9d0d119837fb0bc52d2bb3d48a47568de9100b4 (patch) | |
tree | 6c7550f7e139323bb6169f1f4da6ee6dfe0a8ba4 /lib/stdlib/src | |
parent | 2c72e662bad11a41839780f86680d4bb05367c78 (diff) | |
download | otp-a9d0d119837fb0bc52d2bb3d48a47568de9100b4.tar.gz otp-a9d0d119837fb0bc52d2bb3d48a47568de9100b4.tar.bz2 otp-a9d0d119837fb0bc52d2bb3d48a47568de9100b4.zip |
Handle chardata in string:to_float and string:to_list
Diffstat (limited to 'lib/stdlib/src')
-rw-r--r-- | lib/stdlib/src/string.erl | 71 |
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(). |