a3ef05f · elk · git.iko.soy

git.iko.soy/elk

Speed up exhaustiveness checker.

Results in 5x faster builds on our app. Successive patterns on data constructors like tuples can cause the list of unhandled patterns to grow exponentially. This commit de-duplicates entries in the unhandled patterns list. This tames the exponential growth considerably. The proper solution is to create a real union type for nitpicking patterns. There’s still quite a bit of speed improvement available. Build times (app: Sketch-n-Sketch): Elm 0.16: 2:32.4 Elm 0.16 with this commit: 0:27.8 Elm 0.16 with no exhaustiveness checking: 0:11.3

commita3ef05f4970db808dc61b506b5ff12581c83ac8b authorBrian Hempel <bnhempel@mtu.edu> dateMon 22 Aug 2016, 18:57 (10 years ago) parentee39e7e

3 files changed+17−15

compare with master

unifiedsplit

src/Nitpick/Pattern.hs+1−1 src/Nitpick/PatternMatches.hs+12−11 src/Reporting/Error/Pattern.hs+4−3

src/Nitpick/Pattern.hs+1−1

@@ -17,7 +17,7 @@ data Pattern

1717 | Anything

1818 | Literal L.Literal

1919 | AnythingBut (Set.Set L.Literal)

20− deriving (Eq)

20+ deriving (Eq, Ord)

2121

2222

2323fromCanonicalPattern :: P.Canonical -> Pattern

src/Nitpick/PatternMatches.hs+12−11

@@ -209,25 +209,25 @@ checkExpression tagDict (A.A region expression) =

209209

210210checkPatterns :: TagDict -> Region.Region -> Error.Origin -> [Pattern.Canonical] -> Result wrn ()

211211checkPatterns tagDict region origin patterns =

212− checkPatternsHelp tagDict region origin [Anything] patterns

212+ checkPatternsHelp tagDict region origin (Set.singleton Anything) patterns

213213

214214

215215checkPatternsHelp

216216 :: TagDict

217217 -> Region.Region

218218 -> Error.Origin

219− -> [Pattern]

219+ -> Set.Set Pattern

220220 -> [Pattern.Canonical]

221221 -> Result wrn ()

222222checkPatternsHelp tagDict region origin unhandled patterns =

223− case (unhandled, patterns) of

224− ([], []) ->

225− return ()

226−

227− (_:_, []) ->

228− Result.throw region (Error.Incomplete origin unhandled)

223+ case patterns of

224+ [] ->

225+ if Set.size unhandled == 0 then

226+ return ()

227+ else

228+ Result.throw region (Error.Incomplete origin unhandled)

229229

230− (_, pattern@(A.A localRegion _) : remainingPatterns) ->

230+ pattern@(A.A localRegion _) : remainingPatterns ->

231231 do newUnhandled <- filterPatterns tagDict localRegion pattern unhandled

232232 checkPatternsHelp tagDict region origin newUnhandled remainingPatterns

233233

@@ -236,8 +236,8 @@ filterPatterns

236236 :: TagDict

237237 -> Region.Region

238238 -> Pattern.Canonical

239− -> [Pattern]

240− -> Result wrn [Pattern]

239+ -> Set.Set Pattern

240+ -> Result wrn (Set.Set Pattern)

241241filterPatterns tagDict region pattern unhandled =

242242 let

243243 nitPattern =

@@ -252,6 +252,7 @@ filterPatterns tagDict region pattern unhandled =

252252 else

253253 do let complementPatterns = complement tagDict nitPattern

254254 return $

255+ Set.fromList $

255256 concatMap

256257 (\p -> Maybe.mapMaybe (intersection p) complementPatterns)

257258 unhandled

src/Reporting/Error/Pattern.hs+4−3

@@ -1,6 +1,7 @@

11{-# OPTIONS_GHC -Wall #-}

22module Reporting.Error.Pattern where

4+import qualified Data.Set as Set

45import Text.PrettyPrint.ANSI.Leijen (text)

67import qualified Nitpick.Pattern as Pattern

@@ -11,7 +12,7 @@ import qualified Reporting.Report as Report

1112

1213

1314data Error

14− = Incomplete Origin [Pattern.Pattern]

15+ = Incomplete Origin (Set.Set Pattern.Pattern)

1516 | Redundant

1617

1718

@@ -57,11 +58,11 @@ toReport _localizer err =

5758 (text "Any value with this shape will be handled by a previous pattern.")

5859

5960

60−unhandledError :: [Pattern.Pattern] -> String -> String

61+unhandledError :: Set.Set Pattern.Pattern -> String -> String

6162unhandledError unhandledPatterns relevantMessage =

6263 let

6364 (visiblePatterns, rest) =

64− splitAt 4 unhandledPatterns

65+ splitAt 4 (Set.toList unhandledPatterns)

6566

6667 patternList =

6768 map (Pattern.toString False) visiblePatterns