deprecate srand(rng, filename::AbstractString)

`srand` should accept a seed as second argument; here `filename`
is only an indirect seed, preventing the use a string object as
a direct seed.

Author: rfourquet

NEWS.md

@@ -398,6 +398,8 @@ Deprecated or removed
   * The zero-argument constructor `MersenneTwister()` has been
     deprecated in favor of the explicit `MersenneTwister(0)` ([#16984]).
 
+  * The method `srand(rng, filename, n=4)` has been deprecated ([#21359]).
+
 <!--- generated by NEWS-update.jl: -->
 [#265]: https://github.com/JuliaLang/julia/issues/265
 [#4615]: https://github.com/JuliaLang/julia/issues/4615

base/deprecated.jl

@@ -1310,6 +1310,11 @@ end
 # PR #16984
 @deprecate MersenneTwister() MersenneTwister(0)
 
+# PR #21359
+@deprecate srand(r::MersenneTwister, filename::AbstractString, n::Integer=4) srand(r, read!(filename, Array{UInt32}(Int(n))))
+@deprecate srand(filename::AbstractString, n::Integer=4) srand(read!(filename, Array{UInt32}(Int(n))))
+@deprecate MersenneTwister(filename::AbstractString)  srand(MersenneTwister(0), read!(filename, Array{UInt32}(Int(4))))
+
 # #19635
 for fname in (:ones, :zeros)
     @eval @deprecate ($fname)(T::Type, arr) ($fname)(T, size(arr))

base/random.jl

@@ -213,25 +213,19 @@ function make_seed(n::Integer)
     end
 end
 
-function make_seed(filename::AbstractString, n::Integer)
-    read!(filename, Array{UInt32}(Int(n)))
-end
-
 ## srand()
 
 """
-    srand([rng=GLOBAL_RNG], [seed]) -> rng
-    srand([rng=GLOBAL_RNG], filename, n=4) -> rng
+    srand([rng=GLOBAL_RNG], seed) -> rng
+    srand([rng=GLOBAL_RNG]) -> rng
 
 Reseed the random number generator. If a `seed` is provided, the RNG will give a
 reproducible sequence of numbers, otherwise Julia will get entropy from the system. For
-`MersenneTwister`, the `seed` may be a non-negative integer, a vector of `UInt32` integers
-or a filename, in which case the seed is read from a file (`4n` bytes are read from the file,
-where `n` is an optional argument). `RandomDevice` does not support seeding.
+`MersenneTwister`, the `seed` may be a non-negative integer or a vector of `UInt32` integers.
+`RandomDevice` does not support seeding.
 """
 srand(r::MersenneTwister) = srand(r, make_seed())
 srand(r::MersenneTwister, n::Integer) = srand(r, make_seed(n))
-srand(r::MersenneTwister, filename::AbstractString, n::Integer=4) = srand(r, make_seed(filename, n))
 
 
 function dsfmt_gv_srand()
@@ -250,11 +244,6 @@ function srand(seed::Union{Integer, Vector{UInt32}})
     dsfmt_gv_srand()
 end
 
-function srand(filename::AbstractString, n::Integer=4)
-    srand(GLOBAL_RNG, filename, n)
-    dsfmt_gv_srand()
-end
-
 ## Global RNG
 
 const GLOBAL_RNG = MersenneTwister(0)

test/random.jl

@@ -485,11 +485,8 @@ let g = Base.Random.GLOBAL_RNG,
     @test srand() === g
     @test srand(rand(UInt)) === g
     @test srand(rand(UInt32, rand(1:10))) === g
-    @test srand(@__FILE__) === g
-    @test srand(@__FILE__, rand(1:10)) === g
     @test srand(m) === m
     @test srand(m, rand(UInt)) === m
     @test srand(m, rand(UInt32, rand(1:10))) === m
     @test srand(m, rand(1:10)) === m
-    @test srand(m, @__FILE__, rand(1:10)) === m
 end