Checkpoint

bang.cabal

@@ -39,6 +39,7 @@ executable bang
                        Bang.Syntax.Lexer,
                        Bang.Syntax.Location,
                        Bang.Syntax.Name,
+                       Bang.Syntax.Parser,
                        Bang.Syntax.Token,
                        Paths_bang
   

src/Bang/Syntax/Parser.y

@@ -0,0 +1,76 @@
+{
+{-# OPTION_GHC -w              #-}
+{-# LANGUAGE DeriveFunctor     #-}
+{-# LANGAUGE OverloadedStrings #-}
+module Bang.Syntax.Parser(
+         parseModule
+       , parseExpression
+       , lexWithLayout
+       )
+ where
+
+import Bang.Syntax.Lexer
+import Bang.Syntax.Location
+import Bang.Syntax.Token
+import MonadLib
+
+}
+
+%tokentype { Located Token }
+
+%token
+ '::' { Located $$ (OpIdent "::") }
+
+%monad { Parser }
+%error { parseError }
+
+%name top_module
+
+%%
+
+top_module :: { () }
+ : '::' { () }
+
+{
+
+newtype Parser a = Parser {
+          unParser :: StateT ParserState (ExceptionT Error Id) a
+        }
+ deriving (Functor, Applicative, Monad)
+
+data ParserState = ParserState {
+       psPrecTable :: Map Text Word
+     , psPosition  :: Location
+     }
+
+instance StateM Parser ParserState where
+  get = Parser   get
+  set = Parser . set
+
+instance ExceptionM Parser Error where
+  raise = Parser . raise
+
+instance RunExceptionM Parser Error where
+  try m = Parser (try (unParser m))
+
+lexWithLayout :: Source -> Position -> L.Text -> [Located Token]
+lexWithLayout = undefined
+
+parseModule :: Source -> L.Text -> Parser Module
+parseModule = undefined
+
+parseExpression :: Source -> L.Text -> Parser Module
+parseModule = undefined
+
+parseError :: [Located Token] -> Parser a
+parseError toks =
+  case toks of
+    [] ->
+      raise (Error 
+      addError Nothing ErrParser "Unexpected end of file."
+    (Located p (ErrorTok _) : _) ->
+      addError (Just p) ErrLexer "Lexer error"
+    (Located p _ : _) ->
+      addError (Just p) ErrParser "Parser error"
+
+}

src/Main.hs

@@ -1,6 +1,7 @@
 import           Bang.CommandLine
 import           Bang.Syntax.Lexer
 import           Bang.Syntax.Location
+import           Bang.Syntax.Parser
 import           Control.Exception(tryJust)
 import           Control.Monad(guard)
 import qualified Data.Text.Lazy.IO as T
@@ -24,3 +25,5 @@ runLexer _cmd opts =
        Right txt ->
          do let tokens = lexer (File path) (Just initialPosition) txt
             mapM_ (putStrLn . show) tokens
+
+