How can I use `BTreeMap` instead of `HashMap`?

[HairlessVillager]

I need to ensure that the results of serialization and deserialization are consistent each time. However, HashMap salts the hash process, resulting in inconsistent serialization and deserialization outcomes. I think replacing HashMap with BTreeMap should work, as the latter maintains the lexicographical order of keys. I'd like to ask how this can be implemented.

I've tried to use a customed enum:

enum BTreeMapValue {
    Byte(i8),
    Short(i16),
    Int(i32),
    Long(i64),
    Float(f32),
    Double(f64),
    String(String),
    ByteArray(ByteArray),
    IntArray(IntArray),
    LongArray(LongArray),
    List(Vec<BTreeMapValue>),
    Compound(BTreeMap<String, BTreeMapValue>),
}

let x = BTreeMapValue::Compound(BTreeMap::from([(
    "key1".to_string(),
    BTreeMapValue::String("value1".to_string()),
)]));
let y = fastnbt::to_bytes(&x)?;
println!("{:?}", y);

But when I call .to_bytes, it always raise Error: Error("invalid nbt: no root compound").

[HairlessVillager]

Although forking the repository and then globally searching and replacing to change HashMap to BTreeMap works, this method is clearly too ugly and not very Rust-like.😪

[owengage]

Hey, seems like your enum should work in theory, though the Value type has some shenanigans to make sure that it's strict in its serialise/deserialise. I'm unlikely to get much time to look at this in the next few weeks unfortunately but will get around to it.

[HairlessVillager]

Hi, may I implement BTreeMap as a feature and merge it into this repository?🤔 I will ensure that others will still use HashMap when adding dependencies, but they can use the BTreeMap implementation through this feature. I will also add tests to ensure that the relevant features remain unaffected.

[HairlessVillager]

Hi, may I implement BTreeMap as a feature and merge it into this repository?🤔 I will ensure that others will still use HashMap when adding dependencies, but they can use the BTreeMap implementation through this feature. I will also add tests to ensure that the relevant features remain unaffected.

Hello! How's it going? I've commit this change and create a PR #125 . If you could take the time to review it, I would be very happy. Have a pleasant life!