This method is used in Yi editor to implement a parser / highlighter which does real parsing, but doesn't require reading the whole file (and can be restarted at some arbitrary point after modifications).
Maybe I'm not in the target audience, but I find the article incredibly confusing. Parts of it literally feel like something out of SCIgen.
That kind of text seems to be common with people who do "serious stuff" in functional languages. Ah well - they simply know what's going on and can use theoretical concepts. But this link isn't that bad... It could be better though if they did a `s/parser/lexer/` on that article (even if lexer is a "flat parser" - just to reduce confusion)