WIP: adding transpiler

dsl/app/DSL.hs

@@ -2,15 +2,27 @@
 --
 -- SPDX-License-Identifier: AGPL-3.0-or-later
 
-{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE FlexibleInstances, NoFieldSelectors, OverloadedRecordDot, DuplicateRecordFields #-}
 
-module DSL (parseSubStageDef, SubStage) where
+module DSL (
+  parseSubStageDef,
+  SubStage (..),
+  Head (..),
+  Body (..),
+  When (..),
+  Literal (..),
+  Variable (..),
+  Conjunction (..),
+  Predicate (..)
+  ) where
 
   import qualified Data.ByteString.Lazy as BSL
 
   import Text.Parsec 
   import Debug.Trace (traceShow)
   import Data.Functor ( ($>) )
+  import Data.YAML.Event (ScalarStyle(Literal))
+  import Data.Map (Map, empty, insert)
   
 
   type Stage = [SubStage]
@@ -29,11 +41,17 @@ module DSL (parseSubStageDef, SubStage) where
   data When = Always | Fulfilled | Unfulfilled  deriving Show
 
   data Body = Body {
-    variables :: [Variable],
+    variables :: Map String Variable,
     dnf :: [Conjunction]
   } deriving Show
 
-  data Variable = Single String Literal | Block String Conjunction  deriving Show
+  data Variable = Single {
+      id :: String,
+      lit :: Literal
+    } | Block {
+      id :: String,
+      conj :: Conjunction
+    } deriving Show
 
   type Conjunction = [Literal]
 
@@ -113,11 +131,11 @@ module DSL (parseSubStageDef, SubStage) where
 
 
   parseBody :: Parsec BSL.ByteString u Body
-  parseBody = toBody ([], []) <$> bodyContentParser
+  parseBody = toBody (empty, []) <$> bodyContentParser
     where
-      toBody :: ([Variable], [Conjunction]) -> [Either Variable Conjunction] -> Body
+      toBody :: (Map String Variable, [Conjunction]) -> [Either Variable Conjunction] -> Body
       toBody acc [] = uncurry Body acc
-      toBody (vars, conjs) ((Left v):xs) = toBody (v : vars, conjs) xs
+      toBody (vars, conjs) ((Left v):xs) = toBody (insert v.id v vars, conjs) xs
       toBody (vars, conjs) ((Right c):xs) = toBody (vars, c : conjs) xs
       bodyContentParser :: Parsec BSL.ByteString u [Either Variable Conjunction]
       bodyContentParser = many (spaces *> (try (Left <$> parseVariable) <|> (Right <$> parseCase)))
@@ -155,10 +173,10 @@ module DSL (parseSubStageDef, SubStage) where
                   <|> (PreviousNodes <$> (string "previous_nodes"        *> roundBrackets (try (squareBrackets parseLogVars) <|> parseLogVars)))
 
 
-  parseLogVar :: Parsec BSL.ByteString u String
+  parseLogVar :: Parsec BSL.ByteString u LogVar
   parseLogVar = (:) <$> alphaNum <*> many (try alphaNum <|> oneOf ['-', '_'])
 
-  parseLogVars :: Parsec BSL.ByteString u [String]
+  parseLogVars :: Parsec BSL.ByteString u [LogVar]
   parseLogVars = try ((:) <$> parseLogVar <*> many (spaces *> char ',' *> spaces *> parseLogVar)) <|> (spaces $> [])
 
 

dsl/app/DSLMain.hs

@@ -2,7 +2,7 @@
 --
 -- SPDX-License-Identifier: AGPL-3.0-or-later
 
-module Main where
+module DSLMain where
   import DSL (parseSubStageDef)
 
   import Data.ByteString.Lazy.UTF8 as BSLU

dsl/app/Transpiler.hs

@@ -0,0 +1,122 @@
+-- SPDX-FileCopyrightText: 2023 David Mosbach <david.mosbach@campus.lmu.de>
+--
+-- SPDX-License-Identifier: AGPL-3.0-or-later
+
+{-# LANGUAGE OverloadedRecordDot, OverloadedStrings, NoFieldSelectors, DuplicateRecordFields, TupleSections #-}
+
+module Transpiler where
+  import DSL
+  import Data.YAML (ToYAML (..), mapping, (.=))
+  import Data.Text (Text, pack)
+  import YamlParser (AnchorData (..))
+  import Data.YAML.Event (ScalarStyle(Literal))
+  import Control.Monad.State (State, evalState, get, put, unless, when)
+  import Data.Map (Map, empty)
+  import qualified Data.Map as M
+  import Control.Monad.Except (ExceptT, runExceptT, throwError)
+  import Data.Either (fromLeft)
+  import Data.Maybe (fromJust, isNothing)
+  
+
+  data ResolvedLiteral = Pred' { pred :: Predicate }
+                       | Neg' { pred :: Predicate }  deriving Show
+  
+  data DNFLiteral = DNFLit {
+    anchor  :: AnchorData,
+    literal :: ResolvedLiteral
+  }
+
+  type DNF = [[DNFLiteral]]
+  
+  instance ToYAML SubStage where
+    toYAML(SubStage head body) = mapping [
+        "mode"      .= if head.required then "required" else "optional" :: Text,
+        "show-when" .= case head.showWhen of
+                          Always      -> "always"
+                          Fulfilled   -> "fulfilled"
+                          Unfulfilled -> "unfulfilled" :: Text,
+        "predicate" .= mapping [ "dnf-terms" .= ("" :: Text)] -- toYAML (resolve body) ]
+      ]
+
+  newtype ResolveError = ResolveError String
+
+  data StateData = StateData {
+    innerVariables :: Map String (Variable, Bool), -- True means "already used" => anchor ref. False means "not used before" => new anchor
+    outerVariables :: Map String (Variable, Bool),
+    disjunction    :: DNF
+  }
+
+  type Resolver = ExceptT ResolveError (State StateData) --(Either ResolveError)
+
+  resolve :: Body -> Either ResolveError DNF
+  resolve body = evalState (runExceptT (eval body)) initState
+    where
+      initState = StateData empty (M.map (, False) body.variables) []
+  
+  eval :: Body -> Resolver DNF
+  eval (Body variables []) = get >>= \s -> return s.disjunction
+  eval (Body variables (c:dnf)) = do
+    conjunction <- evalConjunction c []
+    state <- get
+    put $ state {innerVariables = empty, disjunction = conjunction : state.disjunction}
+    eval $ Body variables dnf
+      where
+        evalConjunction :: Conjunction -> [DNFLiteral] -> Resolver [DNFLiteral]
+        evalConjunction [] acc = return acc
+        evalConjunction (l:ls) acc = do
+          lit <- evalLiteral l
+          case lit of
+            Left literal -> evalConjunction ls (literal : acc)
+            Right block -> evalConjunction ls (block ++ acc) -- Merge content of block conjunction variables
+        evalLiteral :: Literal -> Resolver (Either DNFLiteral [DNFLiteral])
+        evalLiteral n@(Neg _) = Left <$> evalNegation n
+        evalLiteral p@(Pred _) = Left <$> evalPredicate p
+        evalLiteral v@(Var _) = evalVariable False v
+        evalNegation :: Literal -> Resolver DNFLiteral -- Resolves redundant negations, e.g. `not not x` and also `let x = not y; let z = not x`
+        evalNegation (Neg n) = do
+          let (lit, count) = countNot 1 n
+          lit' <- case lit of {
+            Pred _ -> evalPredicate lit;
+            Var _ -> evalVariable True lit >>= \l -> return $ fromLeft (error "Preventing negated blocks failed") l;
+            Neg _ -> throwError . ResolveError $ "Could not resolve negation of: " ++ show n;
+          }
+          if even count then return lit' else do
+            let sign = case lit'.literal of {
+              Neg' _ -> Pred';
+              Pred' _ -> Neg';
+            }
+            return lit' { literal = sign lit'.literal.pred }
+        evalNegation x = throwError . ResolveError $ "Wrongfully labelt as negation:  " ++ show x
+        countNot :: Word -> Literal -> (Literal, Word)
+        countNot x (Neg n) = countNot (x+1) n
+        countNot x lit = (lit, x)
+        evalPredicate :: Literal -> Resolver DNFLiteral
+        evalPredicate (Pred (EdgesInHistory _)) = undefined
+        evalPredicate (Pred (NodesInHistory _)) = undefined
+        evalPredicate (Pred (PayloadsFilled _)) = undefined
+        evalPredicate (Pred (PreviousNodes _)) = undefined
+        evalPredicate (Pred p) = return $ DNFLit { anchor = NoAnchor, literal = Pred' p }
+        evalPredicate x = throwError . ResolveError $ "Wrongfully labelt as predicate: " ++ show x
+        evalVariable :: Bool -> Literal -> Resolver (Either DNFLiteral [DNFLiteral])
+        evalVariable negated (Var v) = do
+          state <- get
+          let maybeVar = M.lookup v state.innerVariables
+          if isNothing maybeVar then throwError . ResolveError $ "Reference of unassigned variable: " ++ v else do
+            let (var, alreadyUsed) = fromJust maybeVar
+            unless alreadyUsed . put $ state { innerVariables = M.adjust (\(x,_) -> (x,True)) v state.innerVariables }
+            let anchor = if alreadyUsed then AnchorAlias (pack v) else AnchorDef (pack v)
+            case var of
+              Single _ (Pred p) -> return $ Left DNFLit { anchor = anchor, literal = Pred' p }
+              Single _ v'@(Var _) -> evalVariable negated v'
+              Single _ n@(Neg _) -> Left <$> (evalNegation n >>= \x -> return $ if x.anchor == NoAnchor then x {anchor = anchor} else x)
+              Block id conj -> preventBlockNegation negated id >> Right <$> evalConjunction conj []
+        preventBlockNegation :: Bool -> String -> Resolver ()
+        preventBlockNegation True s = throwError . ResolveError $ "Negating conjunction blocks is not permitted: " ++ s
+        preventBlockNegation False _ = return ()
+
+
+
+  instance ToYAML DNFLiteral where
+    toYAML (DNFLit anchor literal) = mapping [
+        -- "dnf-terms" .= toYAML
+      ]

dsl/dsl.cabal

@@ -1,38 +0,0 @@
-cabal-version:      2.4
-name:               dsl
-version:            0.1.0.0
-
--- A short (one-line) description of the package.
--- synopsis:
-
--- A longer description of the package.
--- description:
-
--- A URL where users can report bugs.
--- bug-reports:
-
--- The license under which the package is released.
--- license:
-author:             David Mosbach
-maintainer:         david.mosbach@live.de
-
--- A copyright notice.
--- copyright:
--- category:
-extra-source-files: CHANGELOG.md
-
-executable dsl
-    main-is:          Main.hs
-
-    -- Modules included in this executable, other than Main.
-    other-modules: DSL
-
-    -- LANGUAGE extensions used by modules in this package.
-    -- other-extensions:
-    build-depends:    base ^>=4.16.4.0,
-                      bytestring,
-                      mtl,
-                      parsec,
-                      utf8-string
-    hs-source-dirs:   app
-    default-language: Haskell2010

workflow-visualiser.cabal

@@ -28,7 +28,10 @@ executable workflow-visualiser
     other-modules: Workflow,
                    Export,
                    Index,
-                   YamlParser
+                   YamlParser,
+                   DSLMain,
+                   DSL,
+                   Transpiler
 
     -- LANGUAGE extensions used by modules in this package.
     -- other-extensions:
@@ -41,6 +44,8 @@ executable workflow-visualiser
                       vector,
                       directory,
                       regex-tdfa,
-                      mtl
+                      mtl,
-    hs-source-dirs:   app
+                      parsec,
+                      utf8-string
+    hs-source-dirs:   app, dsl/app
     default-language: Haskell2010