started a graphviz visualization for the LR(0) automaton

src/runtime/haskell/PGF2.hsc

@@ -72,7 +72,7 @@ module PGF2 (-- * PGF
              graphvizAbstractTree, graphvizParseTree,
              Labels, getDepLabels,
              graphvizDependencyTree, conlls2latexDoc, getCncDepLabels,
-             graphvizWordAlignment,
+             graphvizWordAlignment, graphvizLRAutomaton,
 
              -- * Concrete syntax
              ConcName,Concr,languages,concreteName,languageCode,concreteFlag,
@@ -1389,6 +1389,15 @@ graphvizDependencyTree
   -> String -- ^ Rendered output in the specified format
 graphvizDependencyTree format debug mlab mclab concr t = error "TODO: graphvizDependencyTree"
 
+graphvizLRAutomaton :: Concr -> String
+graphvizLRAutomaton c =
+  unsafePerformIO $
+  withForeignPtr (c_revision c) $ \c_revision ->
+  bracket (withPgfExn "graphvizLRAutomaton" (pgf_graphviz_lr_automaton (c_db c) c_revision)) free $ \c_text ->
+    if c_text == nullPtr
+      then return ""
+      else peekText c_text
+
 ---------------------- should be a separate module?
 
 -- visualization with latex output. AR Nov 2015

src/runtime/haskell/PGF2/FFI.hsc

@@ -315,6 +315,8 @@ foreign import ccall pgf_graphviz_parse_tree :: Ptr PgfDB -> Ptr Concr -> Stable
 
 foreign import ccall pgf_graphviz_word_alignment :: Ptr PgfDB -> Ptr (Ptr Concr) -> CSize -> StablePtr Expr -> Ptr PgfPrintContext -> Ptr PgfMarshaller -> Ptr PgfGraphvizOptions -> Ptr PgfExn -> IO (Ptr PgfText)
 
+foreign import ccall pgf_graphviz_lr_automaton :: Ptr PgfDB -> Ptr Concr -> Ptr PgfExn -> IO (Ptr PgfText)
+
 
 -----------------------------------------------------------------------
 -- Texts