Remove union in IndexMap (jump-dev#1276)

* Remove union in IndexMap

* Add convert from Dict to CleverDict

* Fix MethodError principle for convert

Author: blegat

src/Utilities/CleverDicts.jl

@@ -86,7 +86,7 @@ mutable struct CleverDict{K,V,F<:Function,I<:Function} <: AbstractDict{K,V}
     end
 end
 function CleverDict{K,V}(n::Integer = 0) where {K,V}
-    return CleverDict{K,V}(key_to_index, Base.Fix1(index_to_key, K), n)
+    return CleverDict{K,V}(key_to_index, index_to_key, n)
 end
 
 """
@@ -106,6 +106,13 @@ function key_to_index end
 
 _is_dense(c::CleverDict) = c.is_dense
 
+function _inverse_hash(c::CleverDict{K}, index::Integer) where {K}
+    return c.inverse_hash(Int64(index))::K
+end
+function _inverse_hash(c::CleverDict{K,V,F,typeof(index_to_key)}, index::Integer) where {K,V,F<:Function}
+    return index_to_key(K, Int64(index))::K
+end
+
 """
     add_item(c::CleverDict{K, V}, val::Val)::K where {K, V}
 
@@ -116,7 +123,7 @@ function add_item(c::CleverDict{K,V}, val::V)::K where {K,V}
         error("Keys were added out of order. `add_item` requires that keys are always added in order.")
     end
     # adding a key in order
-    key = c.inverse_hash(Int64(c.last_index + 1))::K
+    key = _inverse_hash(c, c.last_index + 1)
     c[key] = val
     return key
 end
@@ -142,9 +149,9 @@ function Base.haskey(c::CleverDict{K}, key::K) where {K}
     return _is_dense(c) ? c.hash(key)::Int64 in c.set : haskey(c.dict, key)
 end
 
-function Base.keys(c::CleverDict{K}) where {K}
+function Base.keys(c::CleverDict)
     return if _is_dense(c)
-        [c.inverse_hash(Int64(index))::K for index in c.set]
+        [_inverse_hash(c, index) for index in c.set]
     else
         collect(keys(c.dict))
     end
@@ -284,7 +291,7 @@ function Base.iterate(
             return nothing
         else
             el, i = itr
-            new_el = c.inverse_hash(Int64(el))::K => c.vector[el]::V
+            new_el = _inverse_hash(c, el) => c.vector[el]::V
             @static if VERSION >= v"1.4.0"
                 return new_el, State(i[2], i[1])
             else
@@ -318,7 +325,7 @@ function Base.iterate(
             return nothing
         else
             el, i = itr
-            new_el = c.inverse_hash(Int64(el))::K => c.vector[el]::V
+            new_el = _inverse_hash(c, el) => c.vector[el]::V
             @static if VERSION >= v"1.4.0"
                 return new_el, State(i[2], i[1])
             else
@@ -377,4 +384,21 @@ function map_values!(f::Function, d::CleverDict)
     return
 end
 
+function Base.convert(
+    ::Type{CleverDict{K,V,typeof(key_to_index),typeof(index_to_key)}},
+    d::CleverDict{K,V,typeof(key_to_index),typeof(index_to_key)},
+) where {K,V}
+    return d
+end
+function Base.convert(
+    ::Type{CleverDict{K,V,typeof(key_to_index),typeof(index_to_key)}},
+    src::AbstractDict{K,V},
+) where {K,V}
+    dest = CleverDict{K,V}()
+    for key in sort(collect(keys(src)), by=dest.hash)
+        dest[key] = src[key]
+    end
+    return dest
+end
+
 end

src/Utilities/copy.jl

@@ -87,8 +87,8 @@ _index_to_variable(i) = MOI.VariableIndex(i)
 const DenseVariableDict{V} = CleverDicts.CleverDict{
     MOI.VariableIndex,
     V,
-    typeof(MOI.index_value),
-    typeof(_index_to_variable),
+    typeof(CleverDicts.key_to_index),
+    typeof(CleverDicts.index_to_key),
 }
 function dense_variable_dict(::Type{V}, n) where {V}
     return CleverDicts.CleverDict{MOI.VariableIndex,V}(
@@ -99,12 +99,7 @@ function dense_variable_dict(::Type{V}, n) where {V}
 end
 
 struct IndexMap <: AbstractDict{MOI.Index,MOI.Index}
-    # just keeping the union to make it more backward compatible
-    # we should remove as soon as possible.
-    varmap::Union{
-        DenseVariableDict{MOI.VariableIndex},
-        Dict{MOI.VariableIndex,MOI.VariableIndex},
-    }
+    varmap::DenseVariableDict{MOI.VariableIndex}
     conmap::DoubleDicts.MainIndexDoubleDict
 end
 

src/Utilities/vector_of_constraints.jl

@@ -26,7 +26,7 @@ struct VectorOfConstraints{
         MOI.ConstraintIndex{F,S},
         Tuple{F,S},
         typeof(CleverDicts.key_to_index),
-        Base.Fix1{typeof(CleverDicts.index_to_key),DataType}
+        typeof(CleverDicts.index_to_key),
     }
 
     function VectorOfConstraints{F,S}() where {F,S}

test/Utilities/CleverDicts.jl

@@ -249,4 +249,16 @@ CleverDicts.index_to_key(::Type{MyKey}, index::Int64) = MyKey(index)
         @test d[MathOptInterface.VariableIndex(0)] == "b"
         @test_throws ErrorException CleverDicts.add_item(d, "c")
     end
+
+    @testset "convert" begin
+        vals = [MathOptInterface.VariableIndex(-i) for i in 1:10]
+        d = Dict(MathOptInterface.VariableIndex(i) => vals[i] for i in 1:10)
+        T = MathOptInterface.Utilities.DenseVariableDict{MathOptInterface.VariableIndex}
+        c = convert(T, d)
+        @test c isa T
+        @test c.is_dense
+        @test c.last_index == 10
+        @test c.vector == vals
+        @test c === convert(T, c)
+    end
 end