Merge pull request #634 from eulerkochy/swissdict

SwissDict

Author: eulerkochy

README.md

@@ -23,6 +23,7 @@ This package implements a variety of data structures, including
 -   Mutable Binary Heap
 -   Ordered Dicts and Sets
 -   RobinDict (implemented with [Robin Hood Hashing](https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf))
+-   SwissDict (inspired from [SwissTables](https://abseil.io/blog/20180927-swisstables))
 -   Dictionaries with Defaults
 -   Trie
 -   Linked List and Mutable Linked List

docs/make.jl

@@ -19,6 +19,7 @@ makedocs(
         "ordered_containers.md",
         "default_dict.md",
         "robin_dict.md",
+        "swiss_dict.md",
         "trie.md",
         "linked_list.md",
         "mutable_linked_list.md",

docs/src/index.md

@@ -15,6 +15,7 @@ This package implements a variety of data structures, including
 -   Mutable Binary Heap
 -   Ordered Dicts and Sets
 -   RobinDict and OrderedRobinDict (implemented with [Robin Hood Hashing](https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf))
+-   SwissDict (inspired from [SwissTables](https://abseil.io/blog/20180927-swisstables))
 -   Dictionaries with Defaults
 -   Trie
 -   Linked List and Mutable Linked List

docs/src/swiss_dict.md

@@ -0,0 +1,43 @@
+```@meta
+DocTestSetup = :(using DataStructures)
+```
+
+# SwissDict
+
+`SwissDict` provides a standard dictionary, conforming to the AbstractDict protocol, which is inspired from SwissTable developed by Google. This provides improved performance over Dict at extremely high Load Factor.
+
+The interface of `SwissDict` replicates that of `Dict`.
+
+Examples:
+
+```jldoctest
+julia> d = RobinDict{Int, Char}(1 => 'a', 2 => 'b')
+SwissDict{Int64,Char} with 2 entries:
+  1 => 'a'
+  2 => 'b'
+
+julia> d[3] = 'c';
+
+julia> collect(d)
+3-element Array{Pair{Int64,Char},1}:
+ 1 => 'a'
+ 2 => 'b'
+ 3 => 'c'
+
+julia> delete!(d, 2);
+
+julia> d[1]
+'a': ASCII/Unicode U+0061 (category Ll: Letter, lowercase)
+
+julia> d
+SwissDict{Int64,Char} with 2 entries:
+  1 => 'a'
+  3 => 'c'
+
+julia> pop!(d)
+1 => 'a'
+```
+
+```@meta
+DocTestSetup = nothing
+```

src/DataStructures.jl

@@ -46,6 +46,7 @@ module DataStructures
     export MultiDict, enumerateall
     export RobinDict
     export OrderedRobinDict, isordered
+    export SwissDict
 
     export DiBitVector
 
@@ -87,6 +88,7 @@ module DataStructures
     include("container_loops.jl")
     include("robin_dict.jl")
     include("ordered_robin_dict.jl")
+    include("swiss_dict.jl")
     export
         CircularBuffer,
         capacity,

src/ordered_robin_dict.jl

@@ -230,6 +230,7 @@ end
 function Base.get!(default::Base.Callable, h::OrderedRobinDict{K,V}, key0) where {K,V}
     index = get(h.dict, key0, -2)
     index > 0 && return @inbounds h.vals[index]
+    
     v = convert(V, default())
     setindex!(h, v, key0)
     return v