How to implement a "before/after" diff of a json file

[John-Colvin]

I want to find the difference between two json files of unknown structure, showing which entries have been added, changed and removed.

asdf.transform.AsdfNode has added and removed and that's part of the way to doing this, but actually not very convenient. Obviously I can write code to walk the AsdfNode tree by hand, but it seems like AsdfNode should be more helpful here as it's a common class of tasks

[John-Colvin]

should I be looking at mir-ion instead?

[9il]

Interesting. AsdfNode isn't good for that, Asdf number is actually a string.

We need a new type for that, like

import mir.algebraic: Nullable;
alias JsonNode = Nullable!(double, long, string, This[string], This[]);

or

import mir.algebraic: TaggedVariant;
alias TaggedJsonNode = TaggedVariant!(["null_", "float_", "integer", "string", "object", "array"],
    typeof(null), double, long, string, This[string], This[]);

Would RFC6902 work for you? For example, ruby implementation of JSON patch computation.

A possible API can look like

JsonNode jsonDiff(JsonNode from, JsonNode to)
{
    ...
}

This can be an independent algorithm from Asdf and Ion and we can implement conversion utilities between JsonNode and actual JSON backends.