Module jsone

JSON decoding/encoding module.

Description

JSON decoding/encoding module

Data Types

decode_option()

decode_option() = {object_format, tuple | proplist | map}

object_format:
- Decoded JSON object format
- tuple: An object is decoded as {[]} if it is empty, otherwise {[{Key, Value}]}.
- proplist: An object is decoded as [{}] if it is empty, otherwise [{Key, Value}].
- map: An object is decoded as #{} if it is empty, otherwise #{Key => Value}.
- default: map

encode_option()

encode_option() = native_utf8 | {float_format, [float_format_option()]} | {object_key_type, string | scalar | value} | {space, non_neg_integer()} | {indent, non_neg_integer()}

native_utf8:
- Encodes UTF-8 characters as a human-readable(non-escaped) string

{float_format, Optoins}: - Encodes a float()` value in the format which specified by `Options
- default: [{scientific, 20}]

object_key_type: - Allowable object key type
- string: Only string values are allowed (i.e. json_string() type)
- scalar: In addition to string, following values are allowed: nulls, booleans, numerics (i.e. json_scalar() type)
- value: Any json compatible values are allowed (i.e. json_value() type)
- default: string
- NOTE: If scalar or value option is specified, non json_string() key will be automatically converted to a binary() value (e.g. 1 => <<"1">>, #{} => <<"{}">>)

{space, N}:
- Inserts N spaces after every commna and colon
- default: 0

{indent, N}:
- Inserts a newline and N spaces for each level of indentation
- default: 0

float_format_option()

float_format_option() = {scientific, Decimals::0..249} | {decimals, Decimals::0..253} | compact

scientific:
- The float will be formatted using scientific notation with Decimals digits of precision.

decimals:
- The encoded string will contain at most Decimals number of digits past the decimal point.
- If compact is provided the trailing zeros at the end of the string are truncated.

For more details, see erlang:flaot_to_list/2.

  > jsone:encode(1.23).
  <<"1.22999999999999998224e+00">>
 
  > jsone:encode(1.23, [{float_format, [{scientific, 4}]}]).
  <"1.2300e+00">>
 
  > jsone:encode(1.23, [{float_format, [{scientific, 1}]}]).
  <<"1.2e+00">>
 
  > jsone:encode(1.23, [{float_format, [{decimals, 4}]}]).
  <<"1.2300">>
 
  > jsone:encode(1.23, [{float_format, [{decimals, 4}, compact]}]).
  <<"1.23">>

json_array()

json_array() = [json_value()]

json_boolean()

json_boolean() = boolean()

json_number()

json_number() = number()

json_object()

json_object() = json_object_format_tuple() | json_object_format_proplist() | json_object_format_map()

json_object_format_map()

json_object_format_map() = #{}

json_object_format_proplist()

json_object_format_proplist() = [{}] | json_object_members()

json_object_format_tuple()

json_object_format_tuple() = {json_object_members()}

json_object_members()

json_object_members() = [{json_string(), json_value()}]

json_scalar()

json_scalar() = json_boolean() | json_number() | json_string()

json_string()

json_string() = binary() | atom()

NOTE: decode/1 always returns binary() value

json_value()

json_value() = json_number() | json_string() | json_array() | json_object() | json_boolean() | null

Function Index

decode/1Equivalent to decode(Json, []).
decode/2Decodes an erlang term from json text (a utf8 encoded binary).
encode/1Equivalent to encode(JsonValue, []).
encode/2Encodes an erlang term into json text (a utf8 encoded binary).
try_decode/1Equivalent to try_decode(Json, []).
try_decode/2Decodes an erlang term from json text (a utf8 encoded binary).
try_encode/1Equivalent to try_encode(JsonValue, []).
try_encode/2Encodes an erlang term into json text (a utf8 encoded binary).

Function Details

decode/1

decode(Json::binary()) -> json_value()

Equivalent to decode(Json, []).

decode/2

decode(Json::binary(), Options::[decode_option()]) -> json_value()

Decodes an erlang term from json text (a utf8 encoded binary)

Raises an error exception if input is not valid json

  > jsone:decode(<<"1">>, []).
  1
 
  > jsone:decode(<<"wrong json">>, []).
  ** exception error: bad argument
      in function  jsone_decode:number_integer_part/4
         called as jsone_decode:number_integer_part(<<"wrong json">>,1,[],<<>>)
      in call from jsone:decode/1 (src/jsone.erl, line 71)

encode/1

encode(JsonValue::json_value()) -> binary()

Equivalent to encode(JsonValue, []).

encode/2

encode(JsonValue::json_value(), Options::[encode_option()]) -> binary()

Encodes an erlang term into json text (a utf8 encoded binary)

Raises an error exception if input is not an instance of type json_value()

  > jsone:encode([1, null, 2]).
  <<"[1,null,2]">>
 
  > jsone:encode([1, hoge, 2]).  % 'hoge' atom is not a json value
  ** exception error: bad argument
       in function  jsone_encode:value/3
          called as jsone_encode:value(hoge,[{array_values,[2]}],<<"[1,">>)
       in call from jsone:encode/1 (src/jsone.erl, line 97)

try_decode/1

try_decode(Json::binary()) -> {ok, json_value(), Remainings::binary()} | {error, {Reason::term(), [erlang:stack_item()]}}

Equivalent to try_decode(Json, []).

try_decode/2

try_decode(Json::binary(), Options::[decode_option()]) -> {ok, json_value(), Remainings::binary()} | {error, {Reason::term(), [erlang:stack_item()]}}

Decodes an erlang term from json text (a utf8 encoded binary)

  > jsone:try_decode(<<"[1,2,3] \"next value\"">>, []).
  {ok,[1,2,3],<<" \"next value\"">>}
 
  > jsone:try_decode(<<"wrong json">>, []).
  {error,{badarg,[{jsone_decode,number_integer_part,
                                [<<"wrong json">>,1,[],<<>>],
                                [{line,208}]}]}}

try_encode/1

try_encode(JsonValue::json_value()) -> {ok, binary()} | {error, {Reason::term(), [erlang:stack_item()]}}

Equivalent to try_encode(JsonValue, []).

try_encode/2

try_encode(JsonValue::json_value(), Options::[encode_option()]) -> {ok, binary()} | {error, {Reason::term(), [erlang:stack_item()]}}

Encodes an erlang term into json text (a utf8 encoded binary)

  > jsone:try_encode([1, null, 2]).
  {ok,<<"[1,null,2]">>}
 
  > jsone:try_encode([1, hoge, 2]).  % 'hoge' atom is not a json value
  {error,{badarg,[{jsone_encode,value,
                                [hoge,[{array_values,[2]}],<<"[1,">>],
                                [{line,86}]}]}}


Generated by EDoc, Aug 20 2015, 20:17:45.