Implementing enumerate_batches, a function to enumerate batches for a

`Collection`.

src/data/collection.jl

@@ -14,3 +14,27 @@ end
 function get_chunksize(collection::Collection, nranks::Int)
     min(25000, 1 + floor(length(collection.data) / nranks))
 end
+
+function enumerate_batches(collection::Collection, chunksize::Union{Int, Missing} = missing, nranks::Union{Int, Missing} = missing)
+    if ismissing(chunksize)
+        if ismissing(nranks)
+            error("Atleast one of the arguments chunksize or nranks must be specified!")
+        end
+        chunksize = get_chunksize(collection, nranks)
+    end
+
+    num_passages = length(collection.data)
+    batches = Vector{Tuple{Int, Int, Vector{String}}}()
+    chunk_idx, offset = 1, 1
+    while true
+        push!(batches, (chunk_idx, offset, collection.data[offset:min(offset + chunksize - 1, num_passages)]))
+        chunk_idx += 1
+        offset += chunksize
+
+        if offset > num_passages
+            break
+        end
+    end
+    batches
+end
+