src/Rlp/Lex.x

@@ -6,18 +6,19 @@ module Rlp.Lex
     ( P(..)
     , RlpToken(..)
     , Located(..)
-    , AlexPosn
     , lexer
     , lexerCont
     )
     where
 import Control.Monad
 import Data.Functor.Identity
+import Data.Char                (digitToInt)
 import Core.Syntax              (Name)
 import Data.Monoid              (First)
 import Data.Maybe
 import Data.Text                (Text)
 import Data.Text                qualified as T
+import Data.Word
 import Data.Default
 import Lens.Micro.Mtl
 import Lens.Micro
@@ -26,8 +27,6 @@ import Lens.Micro.TH
 import Debug.Trace
 }
 
-%wrapper "monadUserState-strict-text"
-
 $whitechar      = [ \t\n\r\f\v]
 
 $lower          = [a-z \_]
@@ -42,6 +41,8 @@ $namechar       = [$alpha $digit \' \#]
 
 @varname        = $lower $namechar*
 
+@digits         = $digit+
+
 rlp :-
     
     -- skip whitespace
@@ -54,14 +55,13 @@ rlp :-
 
 <0>
 {
-    \n                  ;
-    "{"                 { explicitLBrace `thenBegin` one }
-    ()                  { doLayout `thenBegin` one }
+    \n                  { begin bol }
 }
 
 <one>
 {
     @varname            { tokenWith TokenVarName }
+    @digits             { tokenWith (TokenLitInt . readInt) }
     "="                 { constToken TokenEquals }
     \n                  { begin bol }
 }
@@ -73,29 +73,50 @@ rlp :-
 {
     $whitechar          ;
     \n                  ;
-    ()                  { doBol `andBegin` one }
+    ()                  { doBol }
 }
 
 {
 
+begin = undefined
+
+type LexerAction a = AlexInput -> Int -> P a
+
+type AlexInput =
+    ( Char      -- prev char
+    , Text      -- input
+    )
+
+alexGetByte :: AlexInput -> Maybe (Word8, AlexInput)
+alexGetByte (_,s) = undefined
+
+getInput :: P AlexInput
+getInput = undefined
+
+alexInputPrevChar :: AlexInput -> Char
+alexInputPrevChar = (^. _1)
+
+readInt :: Text -> Int
+readInt = T.foldr f 0 where
+    f c n = digitToInt c + 10*n
+
 -- | @andBegin@, with the subtle difference that the start code is set
 --   /after/ the action
-thenBegin :: AlexAction a -> Int -> AlexAction a
+thenBegin :: LexerAction a -> Int -> LexerAction a
 thenBegin act c inp l = do
     a <- act inp l
-    alexSetStartCode c
-    pure a
+    undefined
 
-constToken :: RlpToken -> AlexAction (Located RlpToken)
-constToken t inp _ = pure $ Located (inp ^. _1) t
+constToken :: RlpToken -> LexerAction (Located RlpToken)
+constToken t inp _ = undefined
 
-tokenWith :: (Text -> RlpToken) -> AlexAction (Located RlpToken)
-tokenWith tf (p,_,_,s) l = pure $ Located p (tf $ T.take l s)
+tokenWith :: (Text -> RlpToken) -> LexerAction (Located RlpToken)
+tokenWith tf inp l = undefined
 
-alexEOF :: Alex (Located RlpToken)
+alexEOF :: P (Located RlpToken)
 alexEOF = do
-    inp <- alexGetInput
-    pure (Located (inp ^. _1) TokenEOF)
+    inp <- getInput
+    pure (Located undefined TokenEOF)
 
 data RlpToken
     -- literals
@@ -123,156 +144,59 @@ data RlpToken
     | TokenEOF
     deriving (Show)
 
-newtype P a = P { runP :: ParseState -> Alex (ParseState, a) }
+newtype P a = P { runP :: ParseState -> (ParseState, Maybe a) }
     deriving (Functor)
 
-execP :: P a -> ParseState -> Text -> Either String a
-execP p st s = snd <$> runAlex s (runP p st)
+execP :: P a -> ParseState -> Either String a
+execP p st = undefined
 
-data ParseState = ParseState { }
+execP' :: P a -> Text -> Either String a
+execP' p s = execP p st where
+    st = initParseState s
 
-instance Default ParseState where
-    def = ParseState { }
+initParseState :: Text -> ParseState
+initParseState s = ParseState
+    { _psLayoutStack = []
+    , _psLexState = [bol,0]
+    , _psInput = (undefined, s)
+    }
+
+data ParseState = ParseState
+    { _psLayoutStack        :: [Layout]
+    , _psLexState           :: [Int]
+    , _psInput              :: AlexInput
+    }
 
 instance Applicative P where
-    pure a = P $ \st -> pure (st,a)
+    pure a = P $ \st -> (st,Just a)
     liftA2 = liftM2
 
 instance Monad P where
-    p >>= k = P $ \st -> do
-        (st',a) <- runP p st
-        runP (k a) st'
-
-data AlexUserState = AlexUserState
-    -- the layout context, along with a start code to return to when the layout
-    -- ends
-    { _ausLayoutStack     :: [(Layout, Int)]
-    }
-    deriving Show
-
-alexInitUserState :: AlexUserState
-alexInitUserState = AlexUserState
-    { _ausLayoutStack = []
-    }
+    p >>= k = undefined
 
 data Layout = Explicit
             | Implicit Int
             deriving (Show, Eq)
 
-data Located a = Located AlexPosn a
+data Located a = Located (Int, Int) a
     deriving (Show)
 
-ausLayoutStack :: Lens' AlexUserState [(Layout, Int)]
-ausLayoutStack = lens _ausLayoutStack
-    (\ s l -> s { _ausLayoutStack = l })
-
 lexer :: P (Located RlpToken)
-lexer = P $ \st -> (st,) <$> lexToken
+lexer = undefined
 
 lexerCont :: (Located RlpToken -> P a) -> P a
-lexerCont = (lexer >>=)
+lexerCont = undefined
 
-lexStream :: Alex [RlpToken]
-lexStream = do
-    t <- lexToken
-    case t of
-        Located _ TokenEOF  -> pure [TokenEOF]
-        Located _ a         -> (a:) <$> lexStream
+lexStream :: P [RlpToken]
+lexStream = undefined
 
 lexTest :: Text -> Either String [RlpToken]
-lexTest = flip runAlex lexStream
+lexTest = undefined
 
-lexToken :: Alex (Located RlpToken)
-lexToken = alexMonadScan
+lexToken :: P (Located RlpToken)
+lexToken = undefined
 
-getsAus :: (AlexUserState -> b) -> Alex b
-getsAus k = alexGetUserState <&> k
-
-useAus :: Getting a AlexUserState a -> Alex a
-useAus l = do
-    aus <- alexGetUserState
-    pure (aus ^. l)
-
-preuseAus :: Getting (First a) AlexUserState a -> Alex (Maybe a)
-preuseAus l = do
-    aus <- alexGetUserState
-    pure (aus ^? l)
-
-modifyingAus :: ASetter' AlexUserState a -> (a -> a) -> Alex () 
-modifyingAus l f = do
-    aus <- alexGetUserState
-    alexSetUserState (aus & l %~ f)
-
-indentLevel :: Alex Int
-indentLevel = do
-    inp <- alexGetInput
-    let col = inp ^. _1
-            & \ (AlexPn _ _ c) -> c
-    pure col
-
-cmpLayout :: Alex Ordering
-cmpLayout = do
-    i <- indentLevel
-    ctx <- preuseAus (ausLayoutStack . _head)
-    case (ctx <&> fst) ^. non (Implicit 1) of
-        Implicit n -> pure (i `compare` n)
-        Explicit   -> pure GT
-
-insertToken :: RlpToken -> Alex (Located RlpToken)
-insertToken t = do
-    inp <- alexGetInput
-    pure (Located (inp ^. _1) t)
-
-insertSemicolon, insertLBrace, insertRBrace :: Alex (Located RlpToken)
-insertSemicolon = traceM "inserting semi" >> insertToken TokenSemicolonV
-insertLBrace = traceM "inserting lbrace" >> insertToken TokenLBraceV
-insertRBrace = traceM "inserting rbrace" >> insertToken TokenRBraceV
-
--- pop the layout stack and jump to the popped return code
-popLayout :: Alex ()
-popLayout = do
-    traceM "pop layout"
-    ctx <- preuseAus (ausLayoutStack . _head)
-    modifyingAus ausLayoutStack (drop 1)
-    case ctx of
-        Just (l,c)  -> alexSetStartCode c
-        Nothing     -> pure ()
-
-pushLayout :: Layout -> Alex ()
-pushLayout l = do
-    traceM "push layout"
-    c <- alexGetStartCode
-    modifyingAus ausLayoutStack ((l,c):)
-
-doBol :: AlexAction (Located RlpToken)
-doBol inp len = do
-    off <- cmpLayout
-    case off of
-        -- the line is aligned with the previous. it therefore belongs to the
-        -- same list
-        EQ -> insertSemicolon
-        -- the line is indented further than the previous, so we assume it is a
-        -- line continuation. ignore it and move on!
-        GT -> undefined -- alexSetStartCode one >> lexToken
-        -- the line is indented less than the previous, pop the layout stack and
-        -- insert a closing brace.
-        LT -> insertRBrace >> popLayout >> lexToken
-
-explicitLBrace, explicitRBrace :: AlexAction (Located RlpToken)
-
-explicitLBrace _ _ = do
-    pushLayout Explicit
-    insertToken TokenLBrace
-
-explicitRBrace _ _ = do
-    popLayout
-    insertToken TokenRBrace
-
-doLayout :: AlexAction (Located RlpToken)
-doLayout _ _ = do
-    i <- indentLevel
-    pushLayout (Implicit i)
-    insertLBrace
+doBol = undefined
 
 }
 

src/Rlp/Lex.x.old

@@ -0,0 +1,280 @@
+{
+{-# LANGUAGE GeneralisedNewtypeDeriving #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Rlp.Lex
+    ( P(..)
+    , RlpToken(..)
+    , Located(..)
+    , AlexPosn
+    , lexer
+    , lexerCont
+    )
+    where
+import Control.Monad
+import Data.Functor.Identity
+import Data.Char                (digitToInt)
+import Core.Syntax              (Name)
+import Data.Monoid              (First)
+import Data.Maybe
+import Data.Text                (Text)
+import Data.Text                qualified as T
+import Data.Default
+import Lens.Micro.Mtl
+import Lens.Micro
+import Lens.Micro.TH
+
+import Debug.Trace
+}
+
+$whitechar      = [ \t\n\r\f\v]
+
+$lower          = [a-z \_]
+$upper          = [A-Z]
+$alpha          = [$lower $upper]
+$digit          = 0-9
+
+$nl             = [\n\r]
+$white_no_nl    = $white # $nl
+
+$namechar       = [$alpha $digit \' \#]
+
+@varname        = $lower $namechar*
+
+@digits         = $digit+
+
+rlp :-
+    
+    -- skip whitespace
+    $white_no_nl+       ;
+    -- TODO: don't treat operators like (-->) as comments
+    "--".*              ;
+    ";"                 { constToken TokenSemicolon }
+    -- "{"                 { explicitLBrace }
+    -- "}"                 { explicitRBrace }
+
+<0>
+{
+    \n                  { begin bol }
+}
+
+<one>
+{
+    @varname            { tokenWith TokenVarName }
+    @digits             { tokenWith (TokenLitInt . readInt) }
+    "="                 { constToken TokenEquals }
+    \n                  { begin bol }
+}
+
+-- consume all whitespace leaving us at the beginning of the next non-empty
+-- line. we then compare the indentation of that line to the enclosing layout
+-- context and proceed accordingly
+<bol>
+{
+    $whitechar          ;
+    \n                  ;
+    ()                  { doBol `andBegin` one }
+}
+
+{
+
+readInt :: Text -> Int
+readInt = T.foldr f 0 where
+    f c n = digitToInt c + 10*n
+
+-- | @andBegin@, with the subtle difference that the start code is set
+--   /after/ the action
+thenBegin :: AlexAction a -> Int -> AlexAction a
+thenBegin act c inp l = do
+    a <- act inp l
+    alexSetStartCode c
+    pure a
+
+constToken :: RlpToken -> AlexAction (Located RlpToken)
+constToken t inp _ = pure $ Located (inp ^. _1) t
+
+tokenWith :: (Text -> RlpToken) -> AlexAction (Located RlpToken)
+tokenWith tf (p,_,_,s) l = pure $ Located p (tf $ T.take l s)
+
+alexEOF :: Alex (Located RlpToken)
+alexEOF = do
+    inp <- alexGetInput
+    pure (Located (inp ^. _1) TokenEOF)
+
+data RlpToken
+    -- literals
+    = TokenLitInt Int
+    -- identifiers
+    | TokenVarName Name
+    | TokenConName Name
+    | TokenVarSym Name
+    | TokenConSym Name
+    -- keywords
+    | TokenData
+    | TokenPipe
+    | TokenLet
+    | TokenIn
+    -- control symbols
+    | TokenEquals
+    | TokenSemicolon
+    | TokenLBrace
+    | TokenRBrace
+    -- 'virtual' control symbols, inserted by the lexer without any correlation
+    -- to a specific symbol
+    | TokenSemicolonV
+    | TokenLBraceV
+    | TokenRBraceV
+    | TokenEOF
+    deriving (Show)
+
+newtype P a = P { runP :: ParseState -> Alex (ParseState, Maybe a) }
+    deriving (Functor)
+
+execP :: P a -> ParseState -> Text -> Either String a
+execP p st s = snd <$> runAlex s (runP p st)
+
+execP' :: P a -> Text -> Either String a
+execP' p = execP p def
+
+data ParseState = ParseState
+    { _psLayoutStack       :: [Layout]
+    , _psLexState          :: [Int]
+    }
+
+instance Default ParseState where
+    def = ParseState { }
+
+instance Applicative P where
+    pure a = P $ \st -> pure (st,a)
+    liftA2 = liftM2
+
+instance Monad P where
+    p >>= k = P $ \st -> do
+        (st',a) <- runP p st
+        runP (k a) st'
+
+data Layout = Explicit
+            | Implicit Int
+            deriving (Show, Eq)
+
+data Located a = Located AlexPosn a
+    deriving (Show)
+
+psLayoutStack :: Lens' AlexUserState [Layout]
+psLayoutStack = lens _psLayoutStack
+    (\ s l -> s { _psLayoutStack = l })
+
+lexer :: P (Located RlpToken)
+lexer = P $ \st -> (st,) <$> lexToken
+
+lexerCont :: (Located RlpToken -> P a) -> P a
+lexerCont = (lexer >>=)
+
+lexStream :: Alex [RlpToken]
+lexStream = do
+    t <- lexToken
+    case t of
+        Located _ TokenEOF  -> pure [TokenEOF]
+        Located _ a         -> (a:) <$> lexStream
+
+lexTest :: Text -> Either String [RlpToken]
+lexTest = flip runAlex lexStream
+
+lexToken :: Alex (Located RlpToken)
+lexToken = alexMonadScan
+
+getsAus :: (AlexUserState -> b) -> Alex b
+getsAus k = alexGetUserState <&> k
+
+useAus :: Getting a AlexUserState a -> Alex a
+useAus l = do
+    aus <- alexGetUserState
+    pure (aus ^. l)
+
+preuseAus :: Getting (First a) AlexUserState a -> Alex (Maybe a)
+preuseAus l = do
+    aus <- alexGetUserState
+    pure (aus ^? l)
+
+modifyingAus :: ASetter' AlexUserState a -> (a -> a) -> Alex () 
+modifyingAus l f = do
+    aus <- alexGetUserState
+    alexSetUserState (aus & l %~ f)
+
+indentLevel :: Alex Int
+indentLevel = do
+    inp <- alexGetInput
+    let col = inp ^. _1
+            & \ (AlexPn _ _ c) -> c
+    pure col
+
+cmpLayout :: Alex Ordering
+cmpLayout = do
+    i <- indentLevel
+    ctx <- preuseAus (ausLayoutStack . _head)
+    case ctx ^. non (Implicit 1) of
+        Implicit n -> pure (i `compare` n)
+        Explicit   -> pure GT
+
+insertToken :: RlpToken -> Alex (Located RlpToken)
+insertToken t = do
+    inp <- alexGetInput
+    pure (Located (inp ^. _1) t)
+
+insertSemicolon, insertLBrace, insertRBrace :: Alex (Located RlpToken)
+insertSemicolon = traceM "inserting semi"   >> insertToken TokenSemicolonV
+insertLBrace    = traceM "inserting lbrace" >> insertToken TokenLBraceV
+insertRBrace    = traceM "inserting rbrace" >> insertToken TokenRBraceV
+
+-- pop the layout stack and jump to the popped return code
+popLayout :: Alex Layout
+popLayout = do
+    traceM "pop layout"
+    ctx <- preuseAus (ausLayoutStack . _head)
+    modifyingAus ausLayoutStack (drop 1)
+    case ctx of
+        Just l      -> pure l
+        Nothing     -> error "uhh"
+
+pushLayout :: Layout -> Alex ()
+pushLayout l = do
+    traceM "push layout"
+    modifyingAus ausLayoutStack (l:)
+
+pushLexState :: Alex ()
+pushLexState = do
+    undefined
+
+doBol :: AlexAction (Located RlpToken)
+doBol inp len = do
+    off <- cmpLayout
+    case off of
+        -- the line is aligned with the previous. it therefore belongs to the
+        -- same list
+        EQ -> insertSemicolon
+        -- the line is indented further than the previous, so we assume it is a
+        -- line continuation. ignore it and move on!
+        GT -> undefined -- alexSetStartCode one >> lexToken
+        -- the line is indented less than the previous, pop the layout stack and
+        -- insert a closing brace.
+        LT -> popLayout >> insertRBrace
+
+explicitLBrace, explicitRBrace :: AlexAction (Located RlpToken)
+
+explicitLBrace _ _ = do
+    pushLayout Explicit
+    insertToken TokenLBrace
+
+explicitRBrace _ _ = do
+    popLayout
+    insertToken TokenRBrace
+
+doLayout :: AlexAction (Located RlpToken)
+doLayout _ _ = do
+    i <- indentLevel
+    pushLayout (Implicit i)
+    traceM $ "layout " <> show i
+    insertLBrace
+
+}
+

src/Rlp/Parse.y

@@ -1,6 +1,6 @@
 {
 module Rlp.Parse
-    (
+    ( parseRlpProgram
     )
     where
 import Rlp.Lex
@@ -8,7 +8,8 @@ import Rlp.Syntax
 import Rlp.Parse.Types
 }
 
-%name rlp
+%name parseRlpProgram StandaloneProgram
+
 %monad { P }
 %lexer { lexerCont } { Located _ TokenEOF }
 %error { parseError }
@@ -16,23 +17,56 @@ import Rlp.Parse.Types
 
 %token
     varname         { Located _ (TokenVarName $$) }
+    litint          { Located _ (TokenLitInt $$) }
     '='             { Located _ TokenEquals }
+    ';'             { Located _ TokenSemicolon }
+    ';?'            { Located _ TokenSemicolonV }
+    '{'             { Located _ TokenLBrace }
+    '}'             { Located _ TokenRBrace }
+    '{?'            { Located _ TokenLBraceV }
+    '?}'            { Located _ TokenRBraceV }
     eof             { Located _ TokenEOF }
 
 %%
 
+StandaloneProgram   :: { [PartialDecl'] }
+StandaloneProgram   : VL Decls VR eof       { $2 }
+
+VL  :: { () }
+VL  : '{?'          { () }
+
+VR  :: { () }
+VR  : '?}'          { () }
+    | error         { () }
+
+Decls               :: { [PartialDecl'] }
+Decls               : Decl Semi Decls       { $1 : $3 }
+                    | Decl Semi             { [$1] }
+                    | Decl                  { [$1] }
+
+Semi                :: { Located RlpToken }
+Semi                : ';'                   { $1 }
+                    | ';?'                  { $1 }
+
 Decl        :: { PartialDecl' }
 Decl        : FunDecl                   { undefined }
 
 FunDecl     :: { PartialDecl' }
 FunDecl     : varname '=' Expr          { undefined }
 
-Expr :: { RlpExpr' }
-Expr :                  { undefined }
+Expr        :: { RlpExpr' }
+Expr        : Literal                   { LitE $1 }
+            | Var                       { VarE $1 }
+
+Literal     :: { Lit' }
+Literal     : litint                    { IntL $1 }
+
+Var         :: { VarId }
+Var         : varname                   { NameVar $1 }
 
 {
 
 parseError :: Located RlpToken -> P a
-parseError = error "aaaaah"
+parseError = error . show
 
 }

src/Rlp/Syntax.hs

@@ -5,6 +5,8 @@
 {-# LANGUAGE OverloadedStrings, PatternSynonyms #-}
 module Rlp.Syntax
     ( RlpModule(..)
+    , RlpProgram(..)
+    , RlpProgram'
     , rlpmodName
     , rlpmodProgram
     , RlpExpr(..)
@@ -54,6 +56,8 @@ data RlpModule b = RlpModule
 
 newtype RlpProgram b = RlpProgram [Decl RlpExpr b]
 
+type RlpProgram' = RlpProgram Name
+
 -- | The @e@ parameter is used for partial results. When parsing an input, we
 -- first parse all top-level declarations in order to extract infix[lr]
 -- declarations. This process yields a @[Decl (Const Text) Name]@, where @Const