TryFromGremlinMap Proc Macro
Closed this issue · 4 comments
Outline
- Initially would be derivable on struct which contains fields which can
Into<GValue>. - Would be great to support serializing into foreign types such as Uuid but will require much more work and I am not sure how the implementation should look. Perhaps its something serde can help with?
Purpose
- Reduce chaining of
.get("field").unwrap().get().unwrap()to just one stepStruct::try_from_map(map)?
@wolf4ood Any ideas on what supporting serialization into foreign types would look like?
Hi @jdeepee
i've started to work a little bit on this on branch gremlin-derive
The final usage should be something like this
Ideally by using FromGValue derive macro we should be able to bind most of the important structs Vertex,Edge,Map etc to custom structs.
WDYT? :)
This is awesome! I just added a PR that allows converting from Map -> custom struct.
The only things left for me would be the ability to have serialization for custom enum's coming from strings in a map as well as serialization of nested types. This is outside of my scope of proc macro knowledge for immediate implementation however.
Example of what I mean:
#[derive(FromGMap)]
enum CustomEnum {
UserType,
UserType2,
}
#[derive(FromGMap)]
struct User {
id: Uuid,
#[gremlin_client(map_value = "type")]
custom_type: CustomEnum,
friends: Vec<User>,
}
let user = g
.add_v("user")
.property("type", CustomEnum::UserType.to_string())
.as_("source_user")
.add_v("user")
.property("type", CustomEnum::UserType.to_string())
.as_("target_user")
.add_("friend")
.from(__.select("source_user"))
.to(__.select("target_user"))
.next();
let user = g
.v(user.id())
.as_("user")
.value_map(true)
.project(vec!["id", "type", "friends"])
.by()
.by()
.by(__.select("user").out("friend").value_map(true));
let user = User::try_from(user)?;