mersinvald / primitive-map-rs Goto Github PK

Implementation of retain is blocked by #10 because of type difference

• insert
• get
• get_mut
• get_key_value
• remove
• remove_entry
• contains_key
• keys
• values
• values_mut
• iter
• iter_mut
• len
• is_empty
• drain
• clear
• into_iter
• Entry API #9
  retain #12 postponed

Currently PrimitiveMap::iter_mut returns Option<&mut (Key, Value)>, that makes it possible to mutate the Key and break the invariant leading to failing lookups by a new value of the Key.

Even anyone who is familiar with principals of HashMap data structure won't try to do so, it should be restricted by the API by returning Option<(Key, &mut Value)> from the iterator.

In the current iterators implementation, the native IntoIterators of used underlying data structures are used, so the solution might be in wrapping Buckets into new types and reimplementing the IntoIterator trait for them with more strict mutation constrains.

BST layered on a Vec/SmallVec structure with map interface should be the default for PrimitiveMap buckets.

Fitstly, it will support immutable keys in iterators to solve the problems described in #10.
Secondly, it should improve performance, as both insertion and querying of entries if O(logn), compared to Vec/SmallVec's O(n) as both operations require looking up the element with the equal key.

Move all benchmarking and test deps into dev deps, make conditional compilation annotations.

Currently, both new and with_capacity methods are described in the BucketStoreNew.
It is implemented by Vec which can implement both, and by Array which can't accept arbitrary capacity in runtime, so it panics at runtime.

https://internals.rust-lang.org/t/default-trait-implementation-and-phantomdata/7429