github/semantic
1
1
Fork 0
mirror of https://github.com/github/semantic.git synced 2024-11-29 11:02:26 +03:00
Code Issues Projects Releases Wiki Activity

Document Interpreter.hs

Browse Source
This commit is contained in:
Matt Diephouse 2016-01-19 13:51:17 -05:00
parent fe472fc60c
commit 3637bfee24
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/Interpreter.hs
View File

@ -20,9 +20,11 @@ import Data.Maybe
-- | Returns whether two terms are comparable
type Comparable a annotation = Term a annotation -> Term a annotation -> Bool
-- | Diff two terms, given a function that determines whether two terms can be compared.
interpret :: (Eq a, Eq annotation) => Comparable a annotation -> Term a annotation -> Term a annotation -> Diff a annotation
interpret comparable a b = fromMaybe (Pure $ Replace a b) $ constructAndRun comparable a b
-- | A hylomorphism. Given an `a`, unfold and then refold into a `b`.
hylo :: Functor f => (t -> f b -> b) -> (a -> (t, f a)) -> a -> b
hylo down up a = down annotation $ hylo down up <$> syntax where
(annotation, syntax) = up a