b17a1a3 · elk · git.iko.soy

Parse nested ifs as a single chunk

Should improve error message quality for expressions like (if … else if …. else if … else …)

commitb17a1a3e88d8c300a3f319f25913bf31a2e91f14 authorEvan Czaplicki <info@elm-lang.org> dateThu 27 Aug 2015, 18:25 (11 years ago) parent2b577fe

1 file changed+10−2

unifiedsplit

src/Parse/Expression.hs+10−2

@@ -213,6 +213,11 @@ binaryExpr =

213213

214214ifExpr :: IParser Source.Expr'

215215ifExpr =

216+ ifHelp []

217+

218+

219+ifHelp :: [(Source.Expr, Source.Expr)] -> IParser Source.Expr'

220+ifHelp branches =

216221 do try (reserved "if")

217222 whitespace

218223 condition <- expr

@@ -221,8 +226,11 @@ ifExpr =

221226 whitespace <?> "an 'else' branch"

222227 reserved "else" <?> "an 'else' branch"

223228 whitespace

224− elseBranch <- expr

225− return (E.If [(condition, thenBranch)] elseBranch)

229+ let newBranches = (condition, thenBranch) : branches

230+ choice

231+ [ ifHelp newBranches

232+ , E.If (reverse newBranches) <$> expr

233+ ]

226234

227235

228236lambdaExpr :: IParser Source.Expr