add removeBetween function to manipulate IntDomain (#430)

src/CP/constraints/sumlessthan.jl

@@ -10,7 +10,7 @@ struct SumLessThan <: Constraint
     numberOfFreeVars    ::StateObject{Int}
     sumOfFixedVars      ::StateObject{Int}
     freeIds             ::Array{Int}
-    function SumLessThan(x::Array{<:AbstractIntVar}, upper::Int,  trailer)
+    function SumLessThan(x::Array{<:AbstractIntVar}, upper::Int, trailer)
         @assert !isempty(x)
 
         freeIds = zeros(length(x))

src/CP/variables/IntDomain.jl

@@ -170,6 +170,26 @@ function removeBelow!(dom::IntDomain, value::Int)
     return pruned
 end
 
+"""
+    removeBetween!(dom::IntDomain, min::Int, max::Int)
+
+Remove every integer of `dom` that is *strictly* between `min` and `max`. Return the pruned values.
+"""
+function removeBetween!(dom::IntDomain, min::Int, max::Int)
+    if dom.max.value < max && dom.min.value > min
+        return removeAll!(dom)
+    end
+
+    pruned = Int[]
+    for i in min+1:(max-1)
+        if i in dom
+            remove!(dom, i)
+            push!(pruned, i)
+        end
+    end
+    return pruned
+end
+
 """
     assign!(dom::IntDomain, value::Int)