Over the last few weeks we have done the work to get everybody up to speed on functional parsing, which is a topic we covered in depth over two years ago and we’ve been wanting to pick up again. And last week we covered something completely new, which is how to change the signature and definition of zip so that it is a little more friendly for parsing because zip on parsers is a little different than zip on other types we’ve encountered it on.

Today we are continuing with parsing, but we are going to unlock a whole new level of functionality. We are going to massively generalize parsing so that it can parse any kind of input into any kind of output. So far all of the parsers we have discussed have been highly tuned to work on strings and substrings. However, there are many things out in the world we’d want to parse, not just strings, and generalizing will allow us to tackle all new problems.

But, even better than opening up new worlds of things we can parse, by generalizing we will also open whole new worlds of composition and we will get access to substantial performance gains, both of which were impossible to see before generalizing.

So, this is incredibly powerful, but it is going to take us time to get there. So let’s start by understanding why it is we’d want to generalize parsing in the first place.