Be more defensive when iterating over sequence that changes dynamically

[zgoda-mobica]

Otherwise you'll get into troubles.

[rockymeza]

Is this in relationship to #42? I'm hesitant to merge this, because while it won't throw an exception, the parsing logic could actually be wrong and I don't want to come out of the loop without parsing all the data. Perhaps we can resolve #42 first before this?

[zgoda-mobica]

You modify sequence you're iterating over by pop()'ing from it, this is only check we still have anything left to consume in the sequence, it does not skip anything.

Other option could be to iterate over a shallow copy.