prepare RNG functionality

Project_tmp

@@ -13,6 +13,7 @@ Expokit = "a1e7a1ef-7a5d-5822-a38c-be74e1bb89f4"
 GLPKMathProgInterface = "3c7084bd-78ad-589a-b5bb-dbd673274bea"
 IntervalArithmetic = "d1acc4aa-44c8-5952-acd4-ba5d80a2a253"
 MathProgBase = "fdba3010-5040-5b88-9595-932c9decdf73"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
 Requires = "ae029012-a4dd-5104-9daa-d747884805df"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"

docs/src/lib/utils.md

@@ -29,6 +29,7 @@ an_element_helper
 binary_search_constraints
 nonzero_indices
 samedir
+reseed
 ```
 
 ### Types

src/LazySet.jl

@@ -239,3 +239,11 @@ function ==(X::LazySet, Y::LazySet)
 
     return true
 end
+
+@static if VERSION >= v"0.7-"
+    # hook into random API
+    import Random.rand
+    function rand(rng::AbstractRNG, ::SamplerType{T}) where T<:LazySet
+        rand(T, rng=rng)
+    end
+end

src/compat.jl

@@ -13,12 +13,15 @@ import Compat.InteractiveUtils.subtypes
 export _At_mul_B
 
 @static if VERSION < v"0.7-"
+    using Compat.Random
     @inline function _At_mul_B(A, B)
         return At_mul_B(A, B)
     end
     expmat = expm
 else
     using SparseArrays
+    using Random
+    using Random: GLOBAL_RNG, SamplerType
     @inline function _At_mul_B(A, B)
         return transpose(A) * B
     end

src/helper_functions.jl

@@ -179,6 +179,31 @@ function nonzero_indices(v::SparseVector{N})::Vector{Int} where N<:Real
     return x.nzind
 end
 
+"""
+    reseed(rng::AbstractRNG, seed::Union{Int, Nothing})::AbstractRNG
+
+Reset the RNG seed if the seed argument is a number.
+
+### Input
+
+- `rng`  -- random number generator
+- `seed` -- seed for reseeding
+
+### Output
+
+The input RNG if the seed is `nothing`, and a reseeded RNG otherwise.
+"""
+function reseed(rng::AbstractRNG, seed::Union{Int, Nothing})::AbstractRNG
+    if seed != nothing
+        @static if VERSION < v"0.7-"
+            return Random.srand(rng, seed)
+        else
+            return Random.seed!(rng, seed)
+        end
+    end
+    return rng
+end
+
 """
     @neutral(SET, NEUT)
 

test/runtests.jl

@@ -63,6 +63,11 @@ if test_suite_polyhedra || test_suite_plotting
 end
 
 if test_suite_basic
+    # =========================
+    # Testing utility functions
+    # =========================
+    @time @testset "LazySets.Util" begin include("unit_util.jl") end
+
     # =======================================
     # Testing types that inherit from LazySet
     # =======================================

test/unit_util.jl

@@ -0,0 +1,10 @@
+for _dummy_ in 1:1 # avoid global variable warnings
+    # reseeding with random seed
+    rng = LazySets.GLOBAL_RNG
+    seed = rand(1:10000)
+    LazySets.reseed(rng, seed)
+    n1 = rand(Int)
+    LazySets.reseed(rng, seed)
+    n2 = rand(Int)
+    @test n1 == n2
+end