chr -package:colour package:scalpel-core

chroot :: (StringLike str, Monad m) => Selector -> ScraperT str m a -> ScraperT str m a
scalpel-core Text.HTML.Scalpel.Core
The chroot function takes a selector and an inner scraper and executes the inner scraper as if it were scraping a document that consists solely of the tags corresponding to the selector. This function will match only the first set of tags matching the selector, to match every set of tags, use chroots.
chroots :: (StringLike str, Monad m) => Selector -> ScraperT str m a -> ScraperT str m [a]
scalpel-core Text.HTML.Scalpel.Core
The chroots function takes a selector and an inner scraper and executes the inner scraper as if it were scraping a document that consists solely of the tags corresponding to the selector. The inner scraper is executed for each set of tags (possibly nested) matching the given selector. 
s = "<div><div>A</div></div>"
scrapeStringLike s (chroots "div" (pure 0)) == Just [0, 0]