make Julia global RNG an instance of MersenneTwister

base/random.jl

@@ -23,10 +23,6 @@ type MersenneTwister <: AbstractRNG
     MersenneTwister() = MersenneTwister(0)
 end
 
-immutable GlobalRNG <: AbstractRNG
-end
-
-typealias MT Union(GlobalRNG, MersenneTwister)
 
 # random numbers of the following types are implemented:
 MTRealTypes = Union(Bool, Integer128, Float16, Float32, Float64)
@@ -100,8 +96,8 @@ srand() = srand(make_seed())
 srand(r::MersenneTwister) = srand(r, make_seed())
 
 function srand(seed::Union(Integer, Vector{Uint32}))
-    global RANDOM_SEED = make_seed(seed)
-    dsfmt_gv_init_by_array(RANDOM_SEED)
+    srand(GlobalRNG(), seed)
+    global RANDOM_SEED = GLOBAL_RNG.seed
 end
 
 function srand(r::MersenneTwister, seed::Union(Integer, Vector{Uint32}))
@@ -114,28 +110,31 @@ srand(filename::String, n::Integer=4) = srand(make_seed(filename, n))
 
 srand(r::MersenneTwister, filename::String, n::Integer=4) = srand(r, make_seed(filename, n))
 
+## Global RNG: needs srand to be instanciated
+
+GLOBAL_RNG = MersenneTwister()
+GlobalRNG() = GLOBAL_RNG
+
 ## random floating point values
 
 rand(r::AbstractRNG) = rand(r, Float64)
 
 # MersenneTwister
-rand(r::GlobalRNG, ::Type{Float64})       = dsfmt_gv_genrand_close_open()
 rand(r::MersenneTwister, ::Type{Float64}) = dsfmt_genrand_close_open(r.state)
 
-rand{T<:Union(Float16, Float32)}(r::MT, ::Type{T}) = convert(T, rand(r))
+rand{T<:Union(Float16, Float32)}(r::MersenneTwister, ::Type{T}) = convert(T, rand(r))
 
 ## random integers (MersenneTwister)
 
-rand(::GlobalRNG, ::Type{Uint32})        = dsfmt_gv_genrand_uint32()
 rand(r::MersenneTwister, ::Type{Uint32}) = dsfmt_genrand_uint32(r.state)
 
-rand(r::MT, ::Type{Bool})    = bool(   rand(r, Uint32) & 1)
-rand(r::MT, ::Type{Uint8})   = uint8(  rand(r, Uint32))
-rand(r::MT, ::Type{Uint16})  = uint16( rand(r, Uint32))
-rand(r::MT, ::Type{Uint64})  = uint64( rand(r, Uint32))<<32 | rand(r, Uint32)
-rand(r::MT, ::Type{Uint128}) = uint128(rand(r, Uint64))<<64 | rand(r, Uint64)
+rand(r::MersenneTwister, ::Type{Bool})    = bool(   rand(r, Uint32) & 1)
+rand(r::MersenneTwister, ::Type{Uint8})   = uint8(  rand(r, Uint32))
+rand(r::MersenneTwister, ::Type{Uint16})  = uint16( rand(r, Uint32))
+rand(r::MersenneTwister, ::Type{Uint64})  = uint64( rand(r, Uint32))<<32 | rand(r, Uint32)
+rand(r::MersenneTwister, ::Type{Uint128}) = uint128(rand(r, Uint64))<<64 | rand(r, Uint64)
 
-rand{T<:Signed128}(r::MT, ::Type{T}) = convert(T, rand(r, as_unsigned(T)))
+rand{T<:Signed128}(r::MersenneTwister, ::Type{T}) = convert(T, rand(r, as_unsigned(T)))
 
 ## random complex values (AbstractRNG)
 
@@ -751,8 +750,7 @@ ziggurat_nor_inv_r  = inv(ziggurat_nor_r)
 ziggurat_exp_r      = 7.6971174701310497140446280481
 
 rand(state::DSFMT_state) = dsfmt_genrand_close_open(state)
-randi() = reinterpret(Uint64,dsfmt_gv_genrand_close1_open2()) & 0x000fffffffffffff
-randi(state::DSFMT_state) = reinterpret(Uint64,dsfmt_genrand_close1_open2(state)) & 0x000fffffffffffff
+randi(state::DSFMT_state=GLOBAL_RNG.state) = reinterpret(Uint64,dsfmt_genrand_close1_open2(state)) & 0x000fffffffffffff
 for (lhs, rhs) in (([], []), 
                   ([:(state::DSFMT_state)], [:state]))
     @eval begin