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Use tryAlignWith in RWS.

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This commit is contained in:
Rob Rix 2018-04-09 16:12:10 -04:00
parent bd17eaa282
commit a5f9cef5be
1 changed files with 5 additions and 5 deletions
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10
src/Diffing/Algorithm/RWS.hs
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@ -14,16 +14,16 @@ module Diffing.Algorithm.RWS
, equalTerms
) where
import Prologue
import Data.Align.Generic (galignWith)
import Control.Monad.State.Strict
import Data.Diff (DiffF(..), deleting, inserting, merge, replacing)
import qualified Data.KdMap.Static as KdMap
import Data.List (sortOn)
import Data.Record
import Data.Term as Term
import Diffing.Algorithm
import Diffing.Algorithm.RWS.FeatureVector
import Diffing.Algorithm.SES
import Prologue
type Label f fields label = forall b. TermF f (Record fields) b -> label
@ -32,7 +32,7 @@ type Label f fields label = forall b. TermF f (Record fields) b -> label
-- This is used both to determine whether two root terms can be compared in O(1), and, recursively, to determine whether two nodes are equal in O(n); thus, comparability is defined s.t. two terms are equal if they are recursively comparable subterm-wise.
type ComparabilityRelation syntax ann1 ann2 = forall a b. TermF syntax ann1 a -> TermF syntax ann2 b -> Bool
rws :: (Foldable syntax, Functor syntax, GAlign syntax)
rws :: (Foldable syntax, Functor syntax, Diffable syntax)
=> ComparabilityRelation syntax (Record (FeatureVector ': fields1)) (Record (FeatureVector ': fields2))
-> (Term syntax (Record (FeatureVector ': fields1)) -> Term syntax (Record (FeatureVector ': fields2)) -> Bool)
-> [Term syntax (Record (FeatureVector ': fields1))]
@ -159,13 +159,13 @@ equalTerms canCompare = go
-- | Return an edit distance between two terms, up to a certain depth.
--
-- Computes a constant-time approximation to the edit distance of a diff. This is done by comparing at most _m_ nodes, & assuming the rest are zero-cost.
editDistanceUpTo :: (GAlign syntax, Foldable syntax, Functor syntax) => Int -> Term syntax ann1 -> Term syntax ann2 -> Int
editDistanceUpTo :: (Diffable syntax, Foldable syntax, Functor syntax) => Int -> Term syntax ann1 -> Term syntax ann2 -> Int
editDistanceUpTo m a b = diffCost m (approximateDiff a b)
where diffCost = flip . cata $ \ diff m -> case diff of
_ | m <= 0 -> 0
Merge body -> sum (fmap ($ pred m) body)
body -> succ (sum (fmap ($ pred m) body))
approximateDiff a b = maybe (replacing a b) (merge (termAnnotation a, termAnnotation b)) (galignWith (Just . these deleting inserting approximateDiff) (termOut a) (termOut b))
approximateDiff a b = maybe (replacing a b) (merge (termAnnotation a, termAnnotation b)) (tryAlignWith (Just . these deleting inserting approximateDiff) (termOut a) (termOut b))
-- Instances