started a graphviz visualization for the LR(0) automaton

src/runtime/c/pgf/pgf.cxx

@@ -3137,3 +3137,30 @@ pgf_align_words(PgfDB *db, PgfConcrRevision revision,
 
     return NULL;
 }
+
+PGF_API PgfText *
+pgf_graphviz_lr_automaton(PgfDB *db, PgfConcrRevision revision,
+                          PgfExn *err)
+{
+    PGF_API_BEGIN {
+        DB_scope scope(db, READER_SCOPE);
+
+        ref<PgfConcr> concr = db->revision2concr(revision);
+
+        PgfPrinter printer(NULL,0,NULL);
+        
+        printer.puts("digraph {");
+        for (size_t i = 0; i < concr->lrtable->len; i++) {
+            ref<PgfLRState> state = vector_elem(concr->lrtable, i);
+            for (size_t j = 0; j < state->shifts->len; j++) {
+                ref<PgfLRShift> shift = vector_elem(state->shifts, j);
+                printer.nprintf(16, "  s%zu -> s%zu;\n", i, shift->next_state);
+            }
+        }
+        printer.puts("}");
+
+        return printer.get_text();
+    } PGF_API_END
+
+    return NULL;
+}

src/runtime/c/pgf/pgf.h

@@ -906,4 +906,8 @@ pgf_align_words(PgfDB *db, PgfConcrRevision revision,
                 size_t *n_phrases /* out */,
                 PgfExn* err);
 
+PGF_API PgfText *
+pgf_graphviz_lr_automaton(PgfDB *db, PgfConcrRevision revision,
+                          PgfExn *err);
+
 #endif // PGF_H_

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