After a few (successful?) attempts at creating DSLs to get structured data from users, I realized that Elixir structs’ syntax fits perfectly what we’re looking for. My idea is to allow users to type in text that’s valid Elixir for given structs (atom keys) and then read/parse that into internal dat…

Just use Code.string_to_quoted and traverse the AST. It is very easy to do

Give us an example what would your users type? If it’s something as simple as name: "James", phone: 123 then you can get away with just using String and Enum.

Code.eval_string/3 is not safe, as you have full access to the runtime system, you can read the warning in the documentation .

My use case is more involved. I can have nested children up to 3 levels deep. For example, this is possible: %Parent{ field: "Value", another_field: "Another value", child_list: [ %Child{ child_field: "Child 1 data", grandchildren_list: [%GrandChild{fiel…

So your users basically type Elixir data structures?

I’ll try this and get back to you. Thank you

For the data you showed perhaps just consider JSON as the user-facing format? Non-evaling conversion to maps/structs without much work by you?

You’re right. The AST is easy to parse. I might settle for this approach. Thanks for pointing this out.

Thanks, @kip JSON would have been my goto approach. However, there are two nuances I have to consider: Any of Parent, Child, and GrandChild in the example above can be the root node, and the system’s behavior adjusts accordingly. GrandChild can be of multiple types and the keys for each are …

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Elixir Programming Language Forum

Parsing a Struct String - Code.eval_string/3? Custom Parser? Other Options?

Questions & Help Questions

kingdomcoder November 23, 2022, 10:31am 7

Exactly