create Map<K, T>::query_all

[0xForerunner]

function signature should probably look something like:

impl<'a, K, T> Map<'a, K, T>
where
    T: Serialize + DeserializeOwned,
    K: PrimaryKey<'a>,
{
        pub fn query_all<Q: CustomQuery>(
        &self,
        querier: &QuerierWrapper<Q>,
        remote_contract: Addr,
        order: Order // Not sure this is required
    ) -> StdResult<Vec<T>> {
        ...
    }
}

The purpose of this function is to allow the querying of external contracts, and should function similarly to the existing Map::query.

[chipshort]

Nice idea.
I think a more generalized version with the semantics of range would be even more useful.

However, I don't think it is actually possible to implement this, since range internally depends on the range implementation provided by Storage and there is no equivalent for querying a range (WasmQuery::Raw only supports querying a single key)

[0xForerunner]

Yeah I don't think using range is possible, though I could be wrong. Either way being able to query the entire vec would be super useful as well!

[chipshort]

The problem is, there is no "entire vec" there. It's all saved individually in storage under the map's key concatenated with the key you put the values into (plus some length-prefixing). So, to my knowledge, the only way to get all the values out is using range or if you know all the keys and query them individually.