a first draft of an API for collaborative editing

src/runtime/c/pgf/parser.cxx

@@ -1605,6 +1605,38 @@ void PgfParser::print_expr_state(PgfMarshaller *m, ExprState *estate)
 }
 #endif
 
+PgfText *PgfParser::get_text() {
+    return sentence;
+}
+
+bool PgfParser::change(size_t start, size_t end, PgfText *change)
+{
+    if (start > sentence->size || end > sentence->size || start > end)
+        return false;
+
+    size_t new_size = sentence->size + change->size - (end-start);
+
+    if (sentence->size < new_size) {
+        PgfText *new_sentence = (PgfText *) realloc(sentence, sizeof(PgfText)+new_size+1);
+        if (new_sentence == NULL)
+            return false;
+        sentence = new_sentence;
+    }
+
+    memcpy(&sentence->text[start+change->size], &sentence->text[end], sentence->size-end);
+    memcpy(&sentence->text[start], change->text, change->size);
+
+    if (sentence->size > new_size) {
+        PgfText *new_sentence = (PgfText *) realloc(sentence, sizeof(PgfText)+new_size+1);
+        if (new_sentence == NULL)
+            return false;
+        sentence = new_sentence;
+    }
+
+    sentence->size = new_size;
+    return true;
+}
+
 PgfParseTableMaker::PgfParseTableMaker(ref<PgfConcr> concr)
     : PgfAbstractParser(concr)
 {

src/runtime/c/pgf/parser.h

@@ -270,7 +270,7 @@ public:
     virtual ~PgfAbstractParser();
 };
 
-class PGF_INTERNAL_DECL PgfParser : private PgfAbstractParser, public PgfExprEnum
+class PGF_INTERNAL_DECL PgfParser : private PgfAbstractParser, public PgfExprEnum, public PgfParseChart
 {
     PgfMarshaller *m;
     PgfUnmarshaller *u;
@@ -314,7 +314,10 @@ public:
 
     void prepare(ref<PgfConcrLincat> start);
 
-    PgfExpr fetch(PgfDB *db, prob_t *prob);
+    virtual PgfExpr fetch(PgfDB *db, prob_t *prob);
+
+    virtual PgfText *get_text();
+    virtual bool change(size_t start, size_t end, PgfText *change);
 };
 
 class PGF_INTERNAL_DECL PgfParseTableMaker : private PgfAbstractParser

src/runtime/c/pgf/pgf.cxx

@@ -2757,6 +2757,38 @@ void pgf_free_expr_enum(PgfExprEnum *en)
     delete en;
 }
 
+PGF_API
+PgfParseChart *pgf_parse_chart(PgfDB *db, PgfConcrRevision revision,
+                               PgfType ty, PgfMarshaller *m, PgfUnmarshaller *u,
+                               PgfText *sentence,
+                               PgfExn * err)
+{
+    PGF_API_BEGIN {
+        DB_scope scope(db, READER_SCOPE);
+
+        ref<PgfConcr> concr = db->revision2concr(revision);
+
+        bool case_sensitive = pgf_is_case_sensitive(concr);
+
+        PgfLincatUnmarshaller lincat_u(concr);
+        m->match_type(&lincat_u, ty);
+        if (lincat_u.lincat == 0)
+            return 0;
+
+        PgfParser *parser = new PgfParser(concr, sentence, case_sensitive, m, u);
+        parser->prepare(lincat_u.lincat);
+        return parser;
+    } PGF_API_END
+
+    return NULL;
+}
+
+PGF_API
+void pgf_free_parse_chart(PgfParseChart *chart)
+{
+    delete chart;
+}
+
 PGF_API
 PgfText *pgf_get_printname(PgfDB *db, PgfConcrRevision revision,
                            PgfText *fun, PgfExn* err)

src/runtime/c/pgf/pgf.h

@@ -830,6 +830,33 @@ PgfExprEnum *pgf_parse(PgfDB *db, PgfConcrRevision revision,
 PGF_API_DECL
 void pgf_free_expr_enum(PgfExprEnum *en);
 
+#ifdef __cplusplus
+struct PgfParseChart {
+    virtual PgfText *get_text()=0;
+    virtual bool change(size_t start, size_t end, PgfText *change)=0;
+    virtual ~PgfParseChart() {};
+};
+#else
+typedef struct PgfParseChart PgfParseChart;
+typedef struct PgfParseChartVtbl PgfParseChartVtbl;
+struct PgfParseChartVtbl {
+    PgfText *(*get_text)(PgfParseChart *this);
+    int (*change)(PgfParseChart *this, size_t start, size_t end, PgfText *change);
+};
+struct PgfParseChart {
+    PgfParseChartVtbl *vtbl;
+};
+#endif
+
+PGF_API_DECL
+PgfParseChart *pgf_parse_chart(PgfDB *db, PgfConcrRevision revision,
+                               PgfType ty, PgfMarshaller *m, PgfUnmarshaller *u,
+                               PgfText *sentence,
+                               PgfExn * err);
+
+PGF_API_DECL
+void pgf_free_parse_chart(PgfParseChart *chart);
+
 PGF_API_DECL
 PgfText *pgf_get_printname(PgfDB *db, PgfConcrRevision revision,
                            PgfText *fun, PgfExn* err);

src/runtime/haskell/PGF2.hsc

@@ -87,6 +87,7 @@ module PGF2 (-- * PGF
 
              -- ** Parsing
              ParseOutput(..), parse, parseWithHeuristics, complete,
+             parseChart, getParseChartText, changeParseChartText,
 
              -- * Exceptions
              PGFError(..),
@@ -872,6 +873,36 @@ enumerateExprs c_db c_revision c_enum_ptr = do
                   rest <- unsafeInterleaveIO (fetchLazy c_fetch c_enum)
                   return ((expr,prob) : rest)
 
+data ParseChart = ParseChart {ch_db :: Ptr PgfDB,
+                              ch_revision :: ForeignPtr Concr,
+                              ch_chart :: ForeignPtr PgfParseChart
+                             }
+
+parseChart :: Concr -> Type -> String -> IO ParseChart
+parseChart c ty sent =
+  withForeignPtr (c_revision c) $ \c_revision_ptr ->
+  bracket (newStablePtr ty) freeStablePtr $ \c_ty ->
+  withText sent $ \c_sent -> do
+    c_chart <- withPgfExn "parseChart" (pgf_parse_chart (c_db c) c_revision_ptr c_ty marshaller unmarshaller c_sent)
+    fptr <- newForeignPtr pgf_free_parse_chart c_chart
+    return (ParseChart (c_db c) (c_revision c) fptr)
+
+getParseChartText :: ParseChart -> IO String
+getParseChartText (ParseChart c_db c_revision c_chart) =
+  withForeignPtr c_chart $ \c_chart_ptr -> do
+    c_get_text <- (#peek PgfParseChartVtbl, get_text) =<< (#peek PgfParseChart, vtbl) c_chart_ptr
+    c_text <- callGetText c_get_text c_chart_ptr
+    peekText c_text
+
+changeParseChartText :: ParseChart -> CSize -> CSize -> String -> IO Bool
+changeParseChartText (ParseChart c_db c_revision c_chart) start end text =
+  withForeignPtr c_revision $ \_ ->
+  withForeignPtr c_chart $ \c_chart_ptr ->
+  withText text $ \c_text -> do
+    c_change <- (#peek PgfParseChartVtbl, change) =<< (#peek PgfParseChart, vtbl) c_chart_ptr
+    c_res <- callChange c_change c_chart_ptr start end c_text
+    return (c_res /= 0)
+
 parseWithHeuristics :: Concr      -- ^ the language with which we parse
                     -> Type       -- ^ the start category
                     -> String     -- ^ the input sentence

src/runtime/haskell/PGF2/FFI.hsc

@@ -49,6 +49,7 @@ data PgfProbsCallback
 data PgfMorphoCallback
 data PgfCohortsCallback
 data PgfExprEnum
+data PgfParseChart
 data PgfAlignmentPhrase
 data PgfParseTableMaker
 
@@ -284,9 +285,17 @@ foreign import ccall pgf_align_words :: Ptr PgfDB -> Ptr Concr -> StablePtr Expr
 
 foreign import ccall pgf_parse :: Ptr PgfDB -> Ptr Concr -> StablePtr Type -> Ptr PgfMarshaller -> Ptr PgfUnmarshaller -> Ptr PgfText -> Ptr PgfExn -> IO (Ptr PgfExprEnum)
 
+foreign import ccall "&pgf_free_expr_enum" pgf_free_expr_enum :: FunPtr (Ptr PgfExprEnum -> IO ())
+
 foreign import ccall "dynamic" callFetch :: Dynamic (Ptr PgfExprEnum -> Ptr PgfDB -> Ptr (#type prob_t) -> IO (StablePtr Expr))
 
-foreign import ccall "&pgf_free_expr_enum" pgf_free_expr_enum :: FunPtr (Ptr PgfExprEnum -> IO ())
+foreign import ccall pgf_parse_chart :: Ptr PgfDB -> Ptr Concr -> StablePtr Type -> Ptr PgfMarshaller -> Ptr PgfUnmarshaller -> Ptr PgfText -> Ptr PgfExn -> IO (Ptr PgfParseChart)
+
+foreign import ccall "&pgf_free_parse_chart" pgf_free_parse_chart :: FunPtr (Ptr PgfParseChart -> IO ())
+
+foreign import ccall "dynamic" callGetText :: Dynamic (Ptr PgfParseChart -> IO (Ptr PgfText))
+
+foreign import ccall "dynamic" callChange :: Dynamic (Ptr PgfParseChart -> CSize -> CSize -> Ptr PgfText -> IO CInt)
 
 foreign import ccall "wrapper" wrapSymbol0 :: Wrapper (Ptr PgfLinearizationOutputIface -> IO ())