# HG changeset patch
# User Jordi Gutiérrez Hermoso <jordigh@octave.org>
# Date 1362069691 18000
# Node ID f279fd604c7e0d309af3efe691514d3f9bd542c8
# Parent  6a6fef2103eb94f381fb442e590244551f98efae# Parent  7eb614760ddb99d2569736c93a84a38ba3fae118
maint: merge in Julien's changes

diff -r 6a6fef2103eb -r f279fd604c7e configure.ac
--- a/configure.ac	Thu Feb 28 08:57:27 2013 +0100
+++ b/configure.ac	Thu Feb 28 11:41:31 2013 -0500
@@ -190,6 +190,17 @@
   AC_DEFINE(BOUNDS_CHECKING, 1, [Define to 1 to use internal bounds checking.])
 fi
 
+### Enable experimental push parser.
+
+OCTAVE_USE_PUSH_PARSER=no
+AC_ARG_ENABLE([push-parser],
+  [AS_HELP_STRING([--enable-push-parser],
+    [enable experimental push parser])],
+  [if test "$enableval" = yes; then OCTAVE_USE_PUSH_PARSER=yes; fi], [])
+if test $OCTAVE_USE_PUSH_PARSER = yes; then
+  AC_DEFINE(OCTAVE_USE_PUSH_PARSER, 1, [Define to 1 to use experimental push parser.])
+fi
+
 ### Use Octave's built-in memory allocator rather than straightforward malloc.
 ### Disabled by default.
 
@@ -2974,6 +2985,7 @@
   Build Java interface:               $build_java
   Do internal array bounds checking:  $BOUNDS_CHECKING
   Use octave_allocator:               $USE_OCTAVE_ALLOCATOR
+  Use push parser:                    $OCTAVE_USE_PUSH_PARSER
   Build static libraries:             $STATIC_LIBS
   Build shared libraries:             $SHARED_LIBS
   Dynamic Linking:                    $ENABLE_DYNAMIC_LINKING $DL_API_MSG
diff -r 6a6fef2103eb -r f279fd604c7e libinterp/parse-tree/lex.h
--- a/libinterp/parse-tree/lex.h	Thu Feb 28 08:57:27 2013 +0100
+++ b/libinterp/parse-tree/lex.h	Thu Feb 28 11:41:31 2013 -0500
@@ -50,13 +50,13 @@
   stream_reader& operator = (const stream_reader&);
 };
 
-// Forward decl for lexical_feedback::token_stack.
+// Forward decl for octave_lexer::token_stack.
 class token;
 
 // For communication between the lexer and parser.
 
 class
-lexical_feedback
+octave_lexer
 {
 public:
 
@@ -153,7 +153,7 @@
     std::stack<int> context;
   };
 
-  lexical_feedback (void)
+  octave_lexer (void)
     : scanner (0), convert_spaces_to_comma (true),
       do_comma_insert (false), at_beginning_of_statement (true),
       looking_at_anon_fcn_args (false), looking_at_return_list (false),
@@ -174,7 +174,7 @@
     init ();
   }
 
-  ~lexical_feedback (void);
+  ~octave_lexer (void);
 
   void init (void);
 
@@ -370,7 +370,7 @@
   bbp_nesting_level nesting_level;
 
   // For unwind protect.
-  static void cleanup (lexical_feedback *lexer) { delete lexer; }
+  static void cleanup (octave_lexer *lexer) { delete lexer; }
 
 private:
 
@@ -381,9 +381,9 @@
 
   // No copying!
 
-  lexical_feedback (const lexical_feedback&);
+  octave_lexer (const octave_lexer&);
 
-  lexical_feedback& operator = (const lexical_feedback&);
+  octave_lexer& operator = (const octave_lexer&);
 };
 
 #endif
diff -r 6a6fef2103eb -r f279fd604c7e libinterp/parse-tree/lex.ll
--- a/libinterp/parse-tree/lex.ll	Thu Feb 28 08:57:27 2013 +0100
+++ b/libinterp/parse-tree/lex.ll	Thu Feb 28 11:41:31 2013 -0500
@@ -109,7 +109,7 @@
 #error lex.l requires flex version 2.5.4 or later
 #endif
 
-#define YY_EXTRA_TYPE lexical_feedback *
+#define YY_EXTRA_TYPE octave_lexer *
 #define curr_lexer yyextra
 
 // Arrange to get input via readline.
@@ -353,7 +353,7 @@
     curr_lexer->at_beginning_of_statement = false;
 
     int c = yytext[yyleng-1];
-    bool cont_is_spc = (curr_lexer->eat_continuation () != lexical_feedback::NO_WHITESPACE);
+    bool cont_is_spc = (curr_lexer->eat_continuation () != octave_lexer::NO_WHITESPACE);
     bool spc_gobbled = (cont_is_spc || c == ' ' || c == '\t');
     int tok_to_return = curr_lexer->handle_close_bracket (spc_gobbled, ']');
 
@@ -379,7 +379,7 @@
     curr_lexer->at_beginning_of_statement = false;
 
     int c = yytext[yyleng-1];
-    bool cont_is_spc = (curr_lexer->eat_continuation () != lexical_feedback::NO_WHITESPACE);
+    bool cont_is_spc = (curr_lexer->eat_continuation () != octave_lexer::NO_WHITESPACE);
     bool spc_gobbled = (cont_is_spc || c == ' ' || c == '\t');
     int tok_to_return = curr_lexer->handle_close_bracket (spc_gobbled, '}');
 
@@ -409,7 +409,7 @@
 
     if (! curr_lexer->looking_at_object_index.front ())
       {
-        if ((tmp & lexical_feedback::NEWLINE) == lexical_feedback::NEWLINE)
+        if ((tmp & octave_lexer::NEWLINE) == octave_lexer::NEWLINE)
           {
             curr_lexer->maybe_warn_separator_insert (';');
 
@@ -446,7 +446,7 @@
             && curr_lexer->nesting_level.is_bracket_or_brace ()
             && curr_lexer->convert_spaces_to_comma)
           {
-            if ((tmp & lexical_feedback::NEWLINE) == lexical_feedback::NEWLINE)
+            if ((tmp & octave_lexer::NEWLINE) == octave_lexer::NEWLINE)
               {
                 curr_lexer->maybe_warn_separator_insert (';');
 
@@ -1284,7 +1284,7 @@
 flex_stream_reader : public stream_reader
 {
 public:
-  flex_stream_reader (lexical_feedback *l, char *buf_arg)
+  flex_stream_reader (octave_lexer *l, char *buf_arg)
     : stream_reader (), lexer (l), buf (buf_arg)
   { }
 
@@ -1299,12 +1299,12 @@
 
   flex_stream_reader& operator = (const flex_stream_reader&);
 
-  lexical_feedback *lexer;
+  octave_lexer *lexer;
 
   char *buf;
 };
 
-lexical_feedback::~lexical_feedback (void)
+octave_lexer::~octave_lexer (void)
 {
   // Clear out the stack of token info used to track line and
   // column numbers.
@@ -1319,7 +1319,7 @@
 }
 
 void
-lexical_feedback::init (void)
+octave_lexer::init (void)
 {
   // The closest paren, brace, or bracket nesting is not an object
   // index.
@@ -1327,14 +1327,14 @@
 
   yylex_init (&scanner);
 
-  // Make lexical_feedback object available through yyextra in
+  // Make octave_lexer object available through yyextra in
   // flex-generated lexer.
   yyset_extra (this, scanner);
 }
 
 // Inside Flex-generated functions, yyg is the scanner cast to its real
 // type.  The BEGIN macro uses yyg and we want to use that in
-// lexical_feedback member functions.  If we could set the start state
+// octave_lexer member functions.  If we could set the start state
 // by calling a function instead of using the BEGIN macro, we could
 // eliminate the OCTAVE_YYG macro.
 
@@ -1342,7 +1342,7 @@
   struct yyguts_t *yyg = static_cast<struct yyguts_t*> (scanner)
 
 void
-lexical_feedback::reset (void)
+octave_lexer::reset (void)
 {
   OCTAVE_YYG;
 
@@ -1372,7 +1372,7 @@
 }
 
 void
-lexical_feedback::prep_for_script_file (void)
+octave_lexer::prep_for_script_file (void)
 {
   OCTAVE_YYG;
 
@@ -1380,7 +1380,7 @@
 }
 
 void
-lexical_feedback::prep_for_function_file (void)
+octave_lexer::prep_for_function_file (void)
 {
   OCTAVE_YYG;
 
@@ -1388,7 +1388,7 @@
 }
 
 int
-lexical_feedback::octave_read (char *buf, unsigned max_size)
+octave_lexer::octave_read (char *buf, unsigned max_size)
 {
   static const char * const eol = "\n";
   static std::string input_buf;
@@ -1452,13 +1452,13 @@
 }
 
 char *
-lexical_feedback::flex_yytext (void)
+octave_lexer::flex_yytext (void)
 {
   return yyget_text (scanner);
 }
 
 int
-lexical_feedback::flex_yyleng (void)
+octave_lexer::flex_yyleng (void)
 {
   return yyget_leng (scanner);
 }
@@ -1469,9 +1469,9 @@
 // that we insert a comma ahead of it.
 
 void
-lexical_feedback::do_comma_insert_check (void)
+octave_lexer::do_comma_insert_check (void)
 {
-  bool spc_gobbled = (eat_continuation () != lexical_feedback::NO_WHITESPACE);
+  bool spc_gobbled = (eat_continuation () != octave_lexer::NO_WHITESPACE);
 
   int c = text_yyinput ();
 
@@ -1485,7 +1485,7 @@
 }
 
 int
-lexical_feedback::text_yyinput (void)
+octave_lexer::text_yyinput (void)
 {
   int c = yyinput (scanner);
 
@@ -1523,7 +1523,7 @@
 }
 
 void
-lexical_feedback::xunput (char c, char *buf)
+octave_lexer::xunput (char c, char *buf)
 {
   if (lexer_debug_flag)
     {
@@ -1539,7 +1539,7 @@
 }
 
 void
-lexical_feedback::xunput (char c)
+octave_lexer::xunput (char c)
 {
   char *yytxt = flex_yytext ();
 
@@ -1550,7 +1550,7 @@
 // really looking at.
 
 void
-lexical_feedback::fixup_column_count (char *s)
+octave_lexer::fixup_column_count (char *s)
 {
   char c;
   while ((c = *s++) != '\0')
@@ -1566,7 +1566,7 @@
 }
 
 bool
-lexical_feedback::inside_any_object_index (void)
+octave_lexer::inside_any_object_index (void)
 {
   bool retval = false;
 
@@ -1586,7 +1586,7 @@
 // Handle keywords.  Return -1 if the keyword should be ignored.
 
 int
-lexical_feedback::is_keyword_token (const std::string& s)
+octave_lexer::is_keyword_token (const std::string& s)
 {
   int l = input_line_number;
   int c = current_input_column;
@@ -1801,7 +1801,7 @@
 }
 
 bool
-lexical_feedback::is_variable (const std::string& name)
+octave_lexer::is_variable (const std::string& name)
 {
   return (symbol_table::is_variable (name)
           || (pending_local_variables.find (name)
@@ -1809,7 +1809,7 @@
 }
 
 std::string
-lexical_feedback::grab_block_comment (stream_reader& reader, bool& eof)
+octave_lexer::grab_block_comment (stream_reader& reader, bool& eof)
 {
   std::string buf;
 
@@ -1915,8 +1915,8 @@
 }
 
 std::string
-lexical_feedback::grab_comment_block (stream_reader& reader, bool at_bol,
-                                      bool& eof)
+octave_lexer::grab_comment_block (stream_reader& reader, bool at_bol,
+                                  bool& eof)
 {
   std::string buf;
 
@@ -2055,7 +2055,7 @@
 }
 
 int
-lexical_feedback::process_comment (bool start_in_block, bool& eof)
+octave_lexer::process_comment (bool start_in_block, bool& eof)
 {
   OCTAVE_YYG;
 
@@ -2109,7 +2109,7 @@
 // replaced by a single LF.
 
 bool
-lexical_feedback::next_token_is_sep_op (void)
+octave_lexer::next_token_is_sep_op (void)
 {
   bool retval = false;
 
@@ -2126,7 +2126,7 @@
 // unary operator.  This is ugly, but it seems to do the right thing.
 
 bool
-lexical_feedback::next_token_is_postfix_unary_op (bool spc_prev)
+octave_lexer::next_token_is_postfix_unary_op (bool spc_prev)
 {
   bool un_op = false;
 
@@ -2173,7 +2173,7 @@
 // parsed as a binary operator.
 
 bool
-lexical_feedback::next_token_is_bin_op (bool spc_prev)
+octave_lexer::next_token_is_bin_op (bool spc_prev)
 {
   bool bin_op = false;
 
@@ -2274,7 +2274,7 @@
 // FIXME -- we need to handle block comments here.
 
 void
-lexical_feedback::scan_for_comments (const char *text)
+octave_lexer::scan_for_comments (const char *text)
 {
   std::string comment_buf;
 
@@ -2335,9 +2335,9 @@
 // FIXME -- we need to handle block comments here.
 
 int
-lexical_feedback::eat_whitespace (void)
+octave_lexer::eat_whitespace (void)
 {
-  int retval = lexical_feedback::NO_WHITESPACE;
+  int retval = octave_lexer::NO_WHITESPACE;
 
   std::string comment_buf;
 
@@ -2359,11 +2359,11 @@
               comment_buf += static_cast<char> (c);
               beginning_of_comment = false;
             }
-          retval |= lexical_feedback::SPACE_OR_TAB;
+          retval |= octave_lexer::SPACE_OR_TAB;
           break;
 
         case '\n':
-          retval |= lexical_feedback::NEWLINE;
+          retval |= octave_lexer::NEWLINE;
           if (in_comment)
             {
               comment_buf += static_cast<char> (c);
@@ -2448,7 +2448,7 @@
 }
 
 void
-lexical_feedback::handle_number (void)
+octave_lexer::handle_number (void)
 {
   double value = 0.0;
   int nread = 0;
@@ -2506,7 +2506,7 @@
 // FIXME -- we need to handle block comments here.
 
 bool
-lexical_feedback::have_continuation (bool trailing_comments_ok)
+octave_lexer::have_continuation (bool trailing_comments_ok)
 {
   std::ostringstream buf;
 
@@ -2594,7 +2594,7 @@
 // line character.
 
 bool
-lexical_feedback::have_ellipsis_continuation (bool trailing_comments_ok)
+octave_lexer::have_ellipsis_continuation (bool trailing_comments_ok)
 {
   char c1 = text_yyinput ();
   if (c1 == '.')
@@ -2618,9 +2618,9 @@
 // whitespace on the next line.
 
 int
-lexical_feedback::eat_continuation (void)
+octave_lexer::eat_continuation (void)
 {
-  int retval = lexical_feedback::NO_WHITESPACE;
+  int retval = octave_lexer::NO_WHITESPACE;
 
   int c = text_yyinput ();
 
@@ -2634,7 +2634,7 @@
 }
 
 int
-lexical_feedback::handle_string (char delim)
+octave_lexer::handle_string (char delim)
 {
   std::ostringstream buf;
 
@@ -2727,7 +2727,7 @@
 }
 
 bool
-lexical_feedback::next_token_is_assign_op (void)
+octave_lexer::next_token_is_assign_op (void)
 {
   bool retval = false;
 
@@ -2811,7 +2811,7 @@
 }
 
 bool
-lexical_feedback::next_token_is_index_op (void)
+octave_lexer::next_token_is_index_op (void)
 {
   int c = text_yyinput ();
   xunput (c);
@@ -2819,7 +2819,7 @@
 }
 
 int
-lexical_feedback::handle_close_bracket (bool spc_gobbled, int bracket_type)
+octave_lexer::handle_close_bracket (bool spc_gobbled, int bracket_type)
 {
   OCTAVE_YYG;
 
@@ -2887,7 +2887,7 @@
 }
 
 void
-lexical_feedback::maybe_unput_comma (int spc_gobbled)
+octave_lexer::maybe_unput_comma (int spc_gobbled)
 {
   if (nesting_level.is_bracket ()
       || (nesting_level.is_brace ()
@@ -2926,7 +2926,7 @@
 }
 
 bool
-lexical_feedback::next_token_can_follow_bin_op (void)
+octave_lexer::next_token_can_follow_bin_op (void)
 {
   std::stack<char> buf;
 
@@ -2968,7 +2968,7 @@
 }
 
 bool
-lexical_feedback::looks_like_command_arg (void)
+octave_lexer::looks_like_command_arg (void)
 {
   bool retval = true;
 
@@ -3190,7 +3190,7 @@
 }
 
 int
-lexical_feedback::handle_superclass_identifier (void)
+octave_lexer::handle_superclass_identifier (void)
 {
   eat_continuation ();
 
@@ -3228,7 +3228,7 @@
 }
 
 int
-lexical_feedback::handle_meta_identifier (void)
+octave_lexer::handle_meta_identifier (void)
 {
   eat_continuation ();
 
@@ -3265,7 +3265,7 @@
 // should be ignored.
 
 int
-lexical_feedback::handle_identifier (void)
+octave_lexer::handle_identifier (void)
 {
   OCTAVE_YYG;
 
@@ -3277,7 +3277,7 @@
 
   int c = yytxt[flex_yyleng()-1];
 
-  bool cont_is_spc = (eat_continuation () != lexical_feedback::NO_WHITESPACE);
+  bool cont_is_spc = (eat_continuation () != octave_lexer::NO_WHITESPACE);
 
   int spc_gobbled = (cont_is_spc || c == ' ' || c == '\t');
 
@@ -3434,7 +3434,7 @@
 }
 
 void
-lexical_feedback::maybe_warn_separator_insert (char sep)
+octave_lexer::maybe_warn_separator_insert (char sep)
 {
   std::string nm = curr_fcn_file_full_name;
 
@@ -3449,7 +3449,7 @@
 }
 
 void
-lexical_feedback::gripe_single_quote_string (void)
+octave_lexer::gripe_single_quote_string (void)
 {
   std::string nm = curr_fcn_file_full_name;
 
@@ -3464,7 +3464,7 @@
 }
 
 void
-lexical_feedback::gripe_matlab_incompatible (const std::string& msg)
+octave_lexer::gripe_matlab_incompatible (const std::string& msg)
 {
   std::string nm = curr_fcn_file_full_name;
 
@@ -3479,20 +3479,20 @@
 }
 
 void
-lexical_feedback::maybe_gripe_matlab_incompatible_comment (char c)
+octave_lexer::maybe_gripe_matlab_incompatible_comment (char c)
 {
   if (c == '#')
     gripe_matlab_incompatible ("# used as comment character");
 }
 
 void
-lexical_feedback::gripe_matlab_incompatible_continuation (void)
+octave_lexer::gripe_matlab_incompatible_continuation (void)
 {
   gripe_matlab_incompatible ("\\ used as line continuation marker");
 }
 
 void
-lexical_feedback::gripe_matlab_incompatible_operator (const std::string& op)
+octave_lexer::gripe_matlab_incompatible_operator (const std::string& op)
 {
   std::string t = op;
   int n = t.length ();
@@ -3502,7 +3502,7 @@
 }
 
 void
-lexical_feedback::push_token (token *tok)
+octave_lexer::push_token (token *tok)
 {
   YYSTYPE *lval = yyget_lval (scanner);
   lval->tok_val = tok;
@@ -3510,14 +3510,14 @@
 }
 
 token *
-lexical_feedback::current_token (void)
+octave_lexer::current_token (void)
 {
   YYSTYPE *lval = yyget_lval (scanner);
   return lval->tok_val;
 }
 
 void
-lexical_feedback::display_token (int tok)
+octave_lexer::display_token (int tok)
 {
   switch (tok)
     {
@@ -3688,7 +3688,7 @@
 }
 
 void
-lexical_feedback::fatal_error (const char *msg)
+octave_lexer::fatal_error (const char *msg)
 {
   error (msg);
 
@@ -3698,7 +3698,7 @@
 }
 
 void
-lexical_feedback::lexer_debug (const char *pattern, const char *text)
+octave_lexer::lexer_debug (const char *pattern, const char *text)
 {
   OCTAVE_YYG;
 
diff -r 6a6fef2103eb -r f279fd604c7e libinterp/parse-tree/oct-parse.yy
--- a/libinterp/parse-tree/oct-parse.yy	Thu Feb 28 08:57:27 2013 +0100
+++ b/libinterp/parse-tree/oct-parse.yy	Thu Feb 28 11:41:31 2013 -0500
@@ -84,7 +84,7 @@
 
 // Global access to currently active lexer.
 // FIXME -- to be removed after more parser+lexer refactoring.
-lexical_feedback *CURR_LEXER = 0;
+octave_lexer *CURR_LEXER = 0;
 
 #if defined (GNULIB_NAMESPACE)
 // Calls to the following functions appear in the generated output from
@@ -166,6 +166,7 @@
 // object) relevant global values before and after the nested call.
 
 %define api.pure
+%define api.push-pull both
 %parse-param { octave_parser *curr_parser }
 %lex-param { void *scanner }
 
@@ -1479,10 +1480,66 @@
   curr_parser->bison_error (s);
 }
 
+octave_parser::~octave_parser (void)
+{
+#if defined (USE_PUSH_PARSER)
+  yypstate_delete (parser_state);
+#endif
+
+delete curr_lexer;
+}
+void octave_parser::init (void)
+{
+#if defined (USE_PUSH_PARSER)
+  parser_state = yypstate_new ();
+#endif
+
+  CURR_LEXER = curr_lexer;
+}
+
 int
 octave_parser::run (void)
 {
-  return octave_parse (this);
+  int status = 0;
+
+#if defined (USE_PUSH_PARSER)
+
+  for (;;)
+    {
+      unwind_protect frame;
+
+      frame.protect_var (current_input_line);
+
+      bool eof = false;
+
+      get_user_input (eof);
+
+      do
+        {
+          octave_char = eof ? END_OF_INPUT : octave_lex ();
+
+          if (octave_char == 0)
+            {
+              // Attempt to get more input.
+              status = -1;
+              break;
+            }
+
+          status = octave_push_parse (pstate);
+        }
+      while (status == YYPUSH_MORE);
+
+      if (status >= 0)
+        break;
+    }
+
+#else
+
+  status = octave_parse (this);
+
+#endif
+
+  return status;
 }
 
 // Error mesages for mismatched end tokens.
diff -r 6a6fef2103eb -r f279fd604c7e libinterp/parse-tree/parse.h
--- a/libinterp/parse-tree/parse.h	Thu Feb 28 08:57:27 2013 +0100
+++ b/libinterp/parse-tree/parse.h	Thu Feb 28 11:41:31 2013 -0500
@@ -131,7 +131,7 @@
 
 // Global access to currently active lexer.
 // FIXME -- to be removed after more parser+lexer refactoring.
-extern lexical_feedback *CURR_LEXER;
+extern octave_lexer *CURR_LEXER;
 
 class
 octave_parser
@@ -144,15 +144,14 @@
       parsing_subfunctions (false), max_fcn_depth (0),
       curr_fcn_depth (0), primary_fcn_scope (-1),
       curr_class_name (), function_scopes (), primary_fcn_ptr (0),
-      curr_lexer (new lexical_feedback ())
+      curr_lexer (new octave_lexer ()), parser_state (0)
   {
-    CURR_LEXER = curr_lexer;
+    init ();
   }
 
-  ~octave_parser (void)
-  {
-    delete curr_lexer;
-  }
+  ~octave_parser (void);
+
+  void init (void);
 
   void reset (void)
   {
@@ -387,7 +386,11 @@
   octave_function *primary_fcn_ptr;
 
   // State of the lexer.
-  lexical_feedback *curr_lexer;
+  octave_lexer *curr_lexer;
+
+  // Internal state of the parser.  Only used if USE_PUSH_PARSER is
+  // defined.
+  void *parser_state;
 
   // For unwind protect.
   static void cleanup (octave_parser *parser) { delete parser; }