Classes and instances parsers

paf31 · paf31 · commit 47eba262d0d8 · 2014-01-12T11:53:13.000-08:00
diff --git a/examples/passing/TypeClasses.purs b/examples/passing/TypeClasses.purs
@@ -0,0 +1,7 @@
+module TypeClasses where
+
+class Show a where
+  show :: a -> String
+
+instance Show String where
+  show s = s
diff --git a/purescript.cabal b/purescript.cabal
@@ -1,5 +1,5 @@
 name: purescript
-version: 0.2.13.1
+version: 0.2.14
 cabal-version: >=1.8
 build-type: Simple
 license: MIT
diff --git a/src/Language/PureScript/Declarations.hs b/src/Language/PureScript/Declarations.hs
@@ -43,4 +43,6 @@ data Declaration
   | ExternDataDeclaration ProperName Kind
   | FixityDeclaration Fixity String
   | ImportDeclaration ModuleName (Maybe [Either Ident ProperName])
+  | TypeClassDeclaration ProperName Ident [Declaration]
+  | TypeInstanceDeclaration ProperName Type [Declaration]
   deriving (Show, D.Data, D.Typeable)
diff --git a/src/Language/PureScript/Parser/Common.hs b/src/Language/PureScript/Parser/Common.hs
@@ -71,7 +71,10 @@ reservedNames = [ "case"
                 , "infixl"
                 , "infixr"
                 , "module"
-                , "let" ]
+                , "let"
+                , "class"
+                , "instance"
+                , "where" ]
 
 builtInOperators :: [String]
 builtInOperators = [ "~", "-", "<=", ">=", "<", ">", "*", "/", "%", "++", "+", "<<", ">>>", ">>"
diff --git a/src/Language/PureScript/Parser/Declarations.hs b/src/Language/PureScript/Parser/Declarations.hs
@@ -96,6 +96,24 @@ parseImportDeclaration = do
   idents <- P.optionMaybe $ parens $ commaSep1 (Left <$> parseIdent <|> Right <$> properName)
   return $ ImportDeclaration moduleName idents
 
+parseTypeClassDeclaration :: P.Parsec String ParseState Declaration
+parseTypeClassDeclaration = do
+  reserved "class"
+  className <- indented *> properName
+  ident <- indented *> parseIdent
+  indented *> reserved "where"
+  members <- mark (P.many (same *> parseTypeDeclaration))
+  return $ TypeClassDeclaration className ident members
+
+parseTypeInstanceDeclaration :: P.Parsec String ParseState Declaration
+parseTypeInstanceDeclaration = do
+  reserved "instance"
+  className <- indented *> properName
+  ty <- indented *> parseType
+  indented *> reserved "where"
+  members <- mark (P.many (same *> parseValueDeclaration))
+  return $ TypeInstanceDeclaration className ty members
+
 parseDeclaration :: P.Parsec String ParseState Declaration
 parseDeclaration = P.choice
                    [ parseDataDeclaration
@@ -104,7 +122,9 @@ parseDeclaration = P.choice
                    , parseValueDeclaration
                    , parseExternDeclaration
                    , parseFixityDeclaration
-                   , parseImportDeclaration ] P.<?> "declaration"
+                   , parseImportDeclaration
+                   , parseTypeClassDeclaration
+                   , parseTypeInstanceDeclaration ] P.<?> "declaration"
 
 parseModule :: P.Parsec String ParseState Module
 parseModule = do
