Hi @BigB84 , we can definitely think about a solution for this case. How are you reading the files and how do you intend to iterate over them?

• Is it a bunch of files and you want to iterate over each of them and the iteration would be the contents of each file?
• Are you thinking about loading a file and iterating over the contents of that single file line by line or byte by byte?

Thanks for reply!

I think it's second case you mentioned.

Actually It's not secret so I can share the actual problem.

I maintain DNS with domain blocklist. Blocklist is built using hostlists.
Hostlists are just text files with domains written line-by-iline but there are plenty of formats. They may be obtained locally from disk or from network by https

Consider just a few formats of hostlists written that way:

127.0.0.1 example.com
127.0.0.1 subdomain.of.example.com
127.0.0.1 another.subdomain.of.example.com
127.0.0.1 something.1.example.com
...

0.0.0.0 example.com
0.0.0.0 subdomain.of.example.com
0.0.0.0 another.subdomain.of.example.com
0.0.0.0 something.2.example.com
...

example.com
subdomain.of.example.com
another.subdomain.of.example.com
something.3.example.com
...

Each one I need to process that way they are cleaned from unwanted expressions (0.0.0.0, 127.0.0.1 etc.).

All set of rules is more complicated, so that's why I use lazy streams for efficient mapping and filtering.

In this case I need reader of type string.
The problem is how to implement such generic reader?

Shall we write two readers for instance: LazyReader of T interface that implements IIterator and LazyLinewiseReader (with fixed T = string) for this specific case?

In the future someone may need to implement reading integers byte by byte so he/she would Implement such reader as LazyIntegerByteReader.

What do you think?