Add support for leading separators (dhall-lang#1355)

* Add support for leading separators ... as standardized in dhall-lang/dhall-lang#755 Note that this does not yet change the formatter to use them * Update `dhall-lang` submodule * Fix `dhall.cabal` to mention new Prelude files * Remove duplicate lines
akshaymankar · Oct 10, 2019 · a24ddfc · a24ddfc
1 parent 9b9d1f5
commit a24ddfc
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/dhall/dhall-lang b/dhall/dhall-lang
diff --git a/dhall/src/Dhall/Parser/Expression.hs b/dhall/src/Dhall/Parser/Expression.hs
@@ -352,8 +352,13 @@ parsers embedded = Parsers {..}
 
             alternative04 = (do
                 _openBrace
+
+                _ <- optional _comma
+
                 a <- recordTypeOrLiteral
+
                 _closeBrace
+
                 return a ) <?> "record type or literal"
 
             alternative05 = unionType
@@ -673,6 +678,8 @@ parsers embedded = Parsers {..}
     unionType = (do
             _openAngle
 
+            _ <- optional _bar
+
             let unionTypeEntry = do
                     a <- anyLabel
                     b <- optional (do _colon; expression)
@@ -688,7 +695,11 @@ parsers embedded = Parsers {..}
 
     listLiteral = (do
             _openBracket
+
+            _ <- optional _comma
+
             a <- Text.Megaparsec.sepBy expression _comma
+
             _closeBracket
             return (ListLit Nothing (Data.Sequence.fromList a)) ) <?> "list literal"
+6 −4		standard/dhall.abnf
+10 −0		tests/parser/success/leadingSeparatorsA.dhall
+1 −0		tests/parser/success/leadingSeparatorsB.dhallb
+1 −0		tests/parser/success/leadingSeparatorsB.diag