将Erlang Maps编码为JSON，并使用字符串进行解析？ [英] Encoding Erlang Maps as JSON with Strings for parsing by Javascript?

问题描述

我正在尝试使用Erlang地图，如

I'm trying to take an Erlang map like

#{"breakfast" => "leftovers"}

并编码为JSON地图。

and encode as a JSON map.

我尝试用jiffy转换列表，例如

I tried converting a list with jiffy for example

(tunnel@127.0.0.1)27> binary_to_list(jiffy:encode(["alpha", "beta"] )).
"[[97,108,112,104,97],[98,101,116,97]]"

但是我不确定如何将其转换为JSON对象。

but I am unsure how to convert that to a JSON object.

当我尝试转换地图时，我会收到 invalid_member_key

When I try to convert a map I get "invalid_member_key"

(tunnel@127.0.0.1)28> jiffy:encode(#{"breakfast" => "egg sandwhich"}).
** exception throw: {error,{invalid_object_member_key,"breakfast"}}
     in function  jiffy:encode/2 (src/jiffy.erl, line 97)

我尝试了列表中漂亮的格式化程序，并获得换行符

I tried the pretty formatter for the list and I get newlines

(tunnel@127.0.0.1)31> binary_to_list(jiffy:encode(["alpha", "beta"], [pretty] )).
"[\n  [\n    97,\n    108,\n    112,\n    104,\n    97\n  ],\n  [\n    98,\n    101,\n    116,\n    97\n  ]\n]"

为什么这不工作？一个json_object是

Why isn't this working? a json_object is

-type json_object() :: {[{json_string(),json_value()}]}
                        | #{json_string() => json_value()}.

所以我期待地图转换工作。我已经尝试搜索并发现阅读JSON的例子，但不是将Erlang转换为可读JSON的工作示例。

so I'm expecting the map conversion to work. I've tried searching and found examples on reading JSON but not a working example of converting Erlang into readable JSON.

推荐答案

是在Erlang中，字符串hello只是一个整数列表。编码Erlang的库映射到JSON将字符串解释为JSON列表，这就是为什么在输出中得到整数的列表。

The problem is that in Erlang the string "hello" is just a list of integer. The libraries that encode Erlang maps into JSON interpret strings as JSON lists, that is why you get a list of integers in the output.

为了获得JSON字符串，您需要使用Erlang二进制文件作为地图中的值：

In order to get JSON strings you need to use Erlang binaries as the values in your maps:

Food = #{<<"breakfast">> => <<"leftovers">>},
jiffy:encode(Food).
%%= <<"{ \"breakfast\" : \"leftovers\" }">>

jiffy 是一致的，所以它也会解码JSON字符串作为Erlang二进制文件，在使用 jiffy：decode / 1 时需要考虑。

jiffy is consistent so it will also decode JSON strings as Erlang binaries, which you need to take into account when using jiffy:decode/1.

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