Remove double scan sampling (#18)

src/UnweightedSamplingMulti.jl

@@ -188,16 +188,8 @@ function choose(n, p, q, z)
     return quantile(b, q)
 end
 
-function double_scan_sampling(rng, iter, n::Int, replace, ordered)
-    N = get_population_size(iter)
-    sortedindices_sample(rng, iter, n, N, replace, ordered)
-end
-
 function sortedindices_sample(rng, iter, n::Int, replace, ordered)
-    return sortedindices_sample(rng, iter, n, length(iter), replace, ordered)
-end
-
-function sortedindices_sample(rng, iter, n::Int, N::Int, replace, ordered)
+    N = length(iter)
     if N <= n
         reservoir = collect(iter)
         if replace
@@ -240,17 +232,6 @@ function sortedindices_sample(rng, iter, n::Int, N::Int, replace, ordered)
     end
 end
 
-function get_population_size(iter)
-    n = 0
-    it = iterate(iter)
-    while !isnothing(it)
-        n += 1
-        @inbounds state = it[2]
-        it = iterate(iter, state)
-    end
-    return n
-end
-
 function get_sorted_indices(rng, n, N, replace)
     if replace == true
         return sortedrandrange(rng, 1:N, n)

src/UnweightedSamplingSingle.jl

@@ -32,17 +32,8 @@ function reservoir_sample(rng, iter)
     end
 end
 
-function double_scan_sampling(rng, iter)
-    N = get_population_size(iter)
-    sortedindices_sample(rng, iter, N)
-end
-
-function sortedindices_sample(rng, iter) 
-    return sortedindices_sample(rng, iter, length(iter))
-end
-
-function sortedindices_sample(rng, iter, N)
-    k = rand(rng, 1:N)
+function sortedindices_sample(rng, iter)
+    k = rand(rng, 1:length(iter))
     for (i, x) in enumerate(iter)
         i == k && return x
     end