Deleting While Iterating in Ruby?
- by Jesse J
I'm iterating over a very large set of strings, which iterates over a smaller set of strings. Due to the size, this method takes a while to do, so to speed it up, I'm trying to delete one of the strings from the smaller set that no longer needs to be used. Below is my current code:
Ms::Fasta.foreach(@database) do |entry|
all.each do |set|
if entry.header[1..40].include? set[1] + "|"
startVal = entry.sequence.scan_i(set[0])[0]
if startVal != nil
@locations << [set[0], set[1], startVal, startVal + set[1].length]
all.delete(set)
end
end
end
end
The problem I face is that the easy way, array.delete(string), effectively adds a break statement to the inner loop, which messes up the results. The only way I know how to fix this is to do this:
Ms::Fasta.foreach(@database) do |entry|
i = 0
while i < all.length
set = all[i]
if entry.header[1..40].include? set[1] + "|"
startVal = entry.sequence.scan_i(set[0])[0]
if startVal != nil
@locations << [set[0], set[1], startVal, startVal + set[1].length]
all.delete_at(i)
i -= 1
end
end
i += 1
end
end
This feels kind of sloppy to me. Is there a better way to do this? Thanks.
