779f7aa · elk · git.iko.soy

git.iko.soy/elk

Remove syntax for record insert and remove

These are pretty much never used in practice. They also can lead to problems if you extend a record with a field that already exists. You could potentially end up with weird behavior, but since this feature is rarely used, we have not actually observed this. Finally, this feature presents an optimization challenge. If the shape of a record can change as it flows through the program, it may become more difficult to optimize code to have constant time field lookups and straightforward field updates.

commit779f7aa10e10af944234f73dc911e96d66cb8374 authorEvan Czaplicki <info@elm-lang.org> dateThu 9 Jul 2015, 12:30 (11 years ago) parent8972f1e

9 files changed+42−155

compare with master

unifiedsplit

src/AST/Expression/General.hs+2−27 src/Canonicalize.hs+2−8 src/Canonicalize/Declaration.hs+5−13 src/Canonicalize/Sort.hs+2−8 src/Generate/JavaScript.hs+1−10 src/Generate/Substitute.hs+2−8 src/Parse/Expression.hs+25−50 src/Type/Constrain/Expression.hs+1−18 src/Validate.hs+2−13

src/AST/Expression/General.hs+2−27

@@ -53,9 +53,7 @@ data Expr' ann def var typ

5353 | Case (Expr ann def var typ) [(Pattern.Pattern ann var, Expr ann def var typ)]

5454 | Data String [Expr ann def var typ]

5555 | Access (Expr ann def var typ) String

56− | Remove (Expr ann def var typ) String

57− | Insert (Expr ann def var typ) String (Expr ann def var typ)

58− | Modify (Expr ann def var typ) [(String, Expr ann def var typ)]

56+ | Update (Expr ann def var typ) [(String, Expr ann def var typ)]

5957 | Record [(String, Expr ann def var typ)]

6058 -- for type checking and code gen only

6159 | Port (PortImpl (Expr ann def var typ) typ)

@@ -215,30 +213,7 @@ instance (P.Pretty def, P.Pretty var, Var.ToString var) => P.Pretty (Expr' ann d

215213 Access record field ->

216214 P.pretty dealiaser True record <> P.text "." <> P.text field

217215

218− Remove record field ->

219− P.braces (P.pretty dealiaser False record <+> P.text "-" <+> P.text field)

220−

221− Insert (A.A _ (Remove record oldField)) newField expr ->

222− P.braces $

223− P.hsep

224− [ P.pretty dealiaser False record

225− , P.text "-"

226− , P.text oldField

227− , P.text "|"

228− , P.text newField

229− , P.equals

230− , P.pretty dealiaser False expr

231− ]

232−

233− Insert record field expr ->

234− P.braces $

235− P.pretty dealiaser False record

236− <+> P.text "|"

237− <+> P.text field

238− <+> P.equals

239− <+> P.pretty dealiaser False expr

240−

241− Modify record fields ->

216+ Update record fields ->

242217 P.braces $

243218 P.hang

244219 (P.pretty dealiaser False record <+> P.text "|")

src/Canonicalize.hs+2−8

@@ -337,14 +337,8 @@ expression env (A.A region validExpr) =

337337 Access record field ->

338338 Access <$> go record <*> Result.ok field

339339

340− Remove record field ->

341− flip Remove field <$> go record

342−

343− Insert record field expr ->

344− flip Insert field <$> go record <*> go expr

345−

346− Modify record fields ->

347− Modify

340+ Update record fields ->

341+ Update

348342 <$> go record

349343 <*> T.traverse (\(field,expr) -> (,) field <$> go expr) fields

350344

src/Canonicalize/Declaration.hs+5−13

@@ -38,28 +38,20 @@ toDefs moduleName (A.A (region,_) decl) =

3838 in

3939 [ definition ctor (buildFunction body vars) region (foldr T.Lambda tbody tipes) ]

4040

41− D.TypeAlias name tvars tipe@(T.Record fields ext) ->

41+ D.TypeAlias name tvars tipe@(T.Record fields Nothing) ->

4242 [ definition name (buildFunction record vars) region (foldr T.Lambda result args) ]

4343 where

4444 result =

4545 T.Aliased (typeVar name) (zip tvars (map T.Var tvars)) (T.Holey tipe)

4646

4747 args =

48− map snd fields ++ maybe [] (:[]) ext

48+ map snd fields

4949

50− var = loc . E.localVar

51− vars = take (length args) infiniteArgs

52−

53− efields =

54− zip (map fst fields) (map var vars)

50+ vars =

51+ take (length args) infiniteArgs

5552

5653 record =

57− case ext of

58− Nothing ->

59− loc (E.Record efields)

60−

61− Just _ ->

62− foldl (\r (f,v) -> loc (E.Insert r f v)) (var (last vars)) efields

54+ loc (E.Record (zip (map fst fields) (map (loc . E.localVar) vars)))

6355

6456 -- Type aliases must be added to an extended equality dictionary,

6557 -- but they do not require any basic constraints.

src/Canonicalize/Sort.hs+2−8

@@ -79,14 +79,8 @@ reorder (A.A ann expression) =

7979 Access record field ->

8080 Access <$> reorder record <*> return field

8181

82− Remove record field ->

83− Remove <$> reorder record <*> return field

84−

85− Insert record field expr ->

86− Insert <$> reorder record <*> return field <*> reorder expr

87−

88− Modify record fields ->

89− Modify

82+ Update record fields ->

83+ Update

9084 <$> reorder record

9185 <*> mapM (\(field,expr) -> (,) field <$> reorder expr) fields

9286

src/Generate/JavaScript.hs+1−10

@@ -77,16 +77,7 @@ expression (A.A region expr) =

7777 do e' <- expression e

7878 return $ DotRef () e' (var (Var.varName field))

7979

80− Remove e field ->

81− do e' <- expression e

82− return $ _Utils "remove" `call` [ string (Var.varName field), e' ]

83−

84− Insert e field value ->

85− do value' <- expression value

86− e' <- expression e

87− return $ _Utils "insert" `call` [ string (Var.varName field), value', e' ]

88−

89− Modify e fields ->

80+ Update e fields ->

9081 do e' <- expression e

9182 fields' <-

9283 forM fields $ \(field, value) ->

src/Generate/Substitute.hs+2−8

@@ -72,14 +72,8 @@ subst old new expression =

7272 Access record field ->

7373 Access (f record) field

7474

75− Remove record field ->

76− Remove (f record) field

77−

78− Insert record field value ->

79− Insert (f record) field (f value)

80−

81− Modify record fields ->

82− Modify (f record) (map (second f) fields)

75+ Update record fields ->

76+ Update (f record) (map (second f) fields)

8377

8478 Record fields ->

8579 Record (map (second f) fields)

src/Parse/Expression.hs+25−50

@@ -134,65 +134,40 @@ parensTerm =

134134

135135recordTerm :: IParser Source.Expr

136136recordTerm =

137− addLocation $

138− brackets (choice [ misc, record ])

139− where

140− record =

141− E.Record <$> commaSep field

142−

143− field =

144− do label <- rLabel

145− patterns <- spacePrefix Pattern.term

146− padded equals

147− body <- expr

148− return (label, makeFunction patterns body)

149−

150− misc =

151− do nextParser <- try miscStarter

152− whitespace

153− nextParser

154−

155− miscStarter =

156− do start <- getMyPosition

157− record <- addLocation (E.rawVar <$> rLabel)

137+ addLocation $ brackets $ choice $

138+ [ do starter <- try (addLocation rLabel)

158139 whitespace

159140 choice

160− [ string "-" >> return (afterMinus start record)

161− , string "|" >> return (afterBar record)

141+ [ update starter

142+ , literal starter

162143 ]

144+ , return (E.Record [])

145+ ]

146+ where

147+ update (A.A ann starter) =

148+ do try (string "|")

149+ whitespace

150+ fields <- commaSep1 field

151+ return (E.Update (A.A ann (E.rawVar starter)) fields)

163152

164− afterMinus start record =

165− do field <- rLabel

166− end <- getMyPosition

167− let subRecord' = E.Remove record field

168− maybe <- optionMaybe (try (whitespace >> string "|"))

169− case maybe of

170− Nothing ->

171− return subRecord'

172− Just _ ->

173− do whitespace

174− field <- rLabel

175− padded equals

176− E.Insert (A.at start end subRecord') field <$> expr

177−

178− afterBar record =

179− do field <- rLabel

153+ literal (A.A _ starter) =

154+ do try (string "<-")

155+ whitespace

156+ value <- expr

180157 whitespace

181158 choice

182− [ do equals

183− whitespace

184− E.Insert record field <$> expr

185− , do leftArrow

159+ [ do try comma

186160 whitespace

187− value <- expr

188− updates <- spaceyPrefixBy comma update

189− return (E.Modify record ((field,value) : updates))

161+ fields <- commaSep field

162+ return (E.Record ((starter, value) : fields))

163+ , return (E.Record [(starter, value)])

190164 ]

191165

192− update =

193− do lbl <- rLabel

194− padded leftArrow

195− (,) lbl <$> expr

166+ field =

167+ do key <- rLabel

168+ padded (string "<-")

169+ value <- expr

170+ return (key, value)

196171

197172

198173term :: IParser Source.Expr

src/Type/Constrain/Expression.hs+1−18

@@ -117,24 +117,7 @@ constrain env annotatedExpr@(A.A region expression) tipe =

117117 exists $ \t ->

118118 constrain env expr (record (Map.singleton label [tipe]) t)

119119

120− E.Remove expr label ->

121− exists $ \t ->

122− constrain env expr (record (Map.singleton label [t]) tipe)

123−

124− E.Insert expr label value ->

125− exists $ \valueType ->

126− exists $ \recordType ->

127− do valueCon <- constrain env value valueType

128− recordCon <- constrain env expr recordType

129− let newRecordType =

130− record (Map.singleton label [valueType]) recordType

131− return $ CAnd

132− [ valueCon

133− , recordCon

134− , CEqual Error.Record region tipe newRecordType

135− ]

136−

137− E.Modify expr fields ->

120+ E.Update expr fields ->

138121 exists $ \t ->

139122 do oldVars <- Monad.forM fields $ \_ -> variable Flexible

140123 let oldFields = ST.fieldMap (zip (map fst fields) (map varN oldVars))

src/Validate.hs+2−13

@@ -221,19 +221,8 @@ expression (A.A ann sourceExpression) =

221221 <$> expression record

222222 <*> return field

223223

224− Remove record field ->

225− Remove

226− <$> expression record

227− <*> return field

228−

229− Insert record field expr ->

230− Insert

231− <$> expression record

232− <*> return field

233− <*> expression expr

234−

235− Modify record fields ->

236− Modify

224+ Update record fields ->

225+ Update

237226 <$> expression record

238227 <*> T.traverse second fields

239228