--- a/build-aux/common.mk	Sat Mar 02 07:59:25 2013 -0800
+++ b/build-aux/common.mk	Sat Mar 02 12:26:42 2013 -0500
@@ -44,6 +44,7 @@
 
 YACC = @YACC@
 AM_YFLAGS = -dv
+BISON_PUSH_PULL_DECL_STYLE = @BISON_PUSH_PULL_DECL_STYLE@
 
 GPERF = @GPERF@
 

--- a/libinterp/Makefile.am	Sat Mar 02 07:59:25 2013 -0800
+++ b/libinterp/Makefile.am	Sat Mar 02 12:26:42 2013 -0500
@@ -65,7 +65,8 @@
 
 BUILT_DISTFILES = \
   parse-tree/oct-gperf.h \
-  parse-tree/oct-parse.h
+  parse-tree/oct-parse.h \
+  parse-tree/oct-parse.yy
 
 ## Files that are created during build process and installed,
 ## BUT not distributed in tarball.
@@ -97,6 +98,7 @@
   mkdefs \
   mkops \
   oct-conf.in.h \
+  oct-parse.in.yy \
   version.in.h \
   $(BUILT_DISTFILES)
 
@@ -196,7 +198,11 @@
   $(LIBOCTINTERP_LINK_OPTS)
 
 ## Section for defining and creating DEF_FILES
-SRC_DEF_FILES := $(shell $(srcdir)/find-defun-files.sh "$(srcdir)" $(DIST_SRC))
+
+ULT_DIST_SRC := \
+  $(filter-out parse-tree/oct-parse.yy, $(DIST_SRC)) parse-tree/oct-parse.in.yy
+
+SRC_DEF_FILES := $(shell $(srcdir)/find-defun-files.sh "$(srcdir)" $(ULT_DIST_SRC))
 
 DLDFCN_DEF_FILES = $(DLDFCN_SRC:.cc=.df)
 
@@ -236,7 +242,7 @@
 
 ## Rules to build test files
 
-TST_FILES_SRC := $(shell $(top_srcdir)/build-aux/find-files-with-tests.sh "$(srcdir)" $(DIST_SRC) $(DLDFCN_SRC))
+TST_FILES_SRC := $(shell $(top_srcdir)/build-aux/find-files-with-tests.sh "$(srcdir)" $(ULT_DIST_SRC) $(DLDFCN_SRC))
 
 TST_FILES := $(addsuffix -tst,$(TST_FILES_SRC))
 

--- a/libinterp/find-defun-files.sh	Sat Mar 02 07:59:25 2013 -0800
+++ b/libinterp/find-defun-files.sh	Sat Mar 02 12:26:42 2013 -0500
@@ -21,6 +21,6 @@
     file="$srcdir/$arg"
   fi
   if [ "`$EGREP -l "$DEFUN_PATTERN" $file`" ]; then
-    echo "$file" | $SED "s,\\$srcdir/,," | $SED 's/\.cc$/.df/; s/\.ll$/.df/; s/\.yy$/.df/';
+    echo "$file" | $SED "s,\\$srcdir/,," | $SED 's/\.cc$/.df/; s/\.ll$/.df/; s/\.in.yy$/.df/';
   fi
 done

--- a/libinterp/parse-tree/module.mk	Sat Mar 02 07:59:25 2013 -0800
+++ b/libinterp/parse-tree/module.mk	Sat Mar 02 12:26:42 2013 -0500
@@ -92,6 +92,18 @@
 	mv $@-t $@
 	rm -f $@-t1
 
+parse-tree/oct-parse.yy: parse-tree/oct-parse.in.yy
+	case "$(BISON_PUSH_PULL_DECL_STYLE)" in \
+          *quote*) quote='"' ;; \
+	  *) quote="" ;; \
+        esac; \
+        case "$(BISON_PUSH_PULL_DECL_STYLE)" in \
+          *dash*) decl="%define api.push-pull $${quote}both$${quote}"; ;; \
+          *underscore*) decl="%define api.push_pull $${quote}both$${quote}"; ;; \
+        esac; \
+	$(SED) "s/%PUSH_PULL_DECL%/$$decl/" $< > $@-t
+	mv $@-t $@
+
 noinst_LTLIBRARIES += parse-tree/libparse-tree.la
 
 parse_tree_libparse_tree_la_SOURCES = $(PARSE_TREE_SRC)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libinterp/parse-tree/oct-parse.in.yy	Sat Mar 02 12:26:42 2013 -0500
@@ -0,0 +1,4589 @@
+/*
+
+Copyright (C) 1993-2012 John W. Eaton
+Copyright (C) 2009 David Grundberg
+Copyright (C) 2009-2010 VZLU Prague
+
+This file is part of Octave.
+
+Octave is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+Octave is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, see
+<http://www.gnu.org/licenses/>.
+
+*/
+
+// Parser for Octave.
+
+// C decarations.
+
+%{
+#define YYDEBUG 1
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <cassert>
+#include <cstdio>
+#include <cstdlib>
+
+#include <iostream>
+#include <map>
+#include <sstream>
+
+#include "Cell.h"
+#include "Matrix.h"
+#include "cmd-edit.h"
+#include "cmd-hist.h"
+#include "file-ops.h"
+#include "file-stat.h"
+#include "oct-env.h"
+#include "oct-time.h"
+#include "quit.h"
+
+#include "comment-list.h"
+#include "defaults.h"
+#include "defun.h"
+#include "dirfns.h"
+#include "dynamic-ld.h"
+#include "error.h"
+#include "input.h"
+#include "lex.h"
+#include "load-path.h"
+#include "oct-hist.h"
+#include "oct-map.h"
+#include "ov-fcn-handle.h"
+#include "ov-usr-fcn.h"
+#include "ov-null-mat.h"
+#include "toplev.h"
+#include "pager.h"
+#include "parse.h"
+#include "parse-private.h"
+#include "pt-all.h"
+#include "pt-eval.h"
+#include "symtab.h"
+#include "token.h"
+#include "unwind-prot.h"
+#include "utils.h"
+#include "variables.h"
+
+// oct-parse.h must be included after pt-all.h
+#include <oct-parse.h>
+
+extern int octave_lex (YYSTYPE *, void *);
+
+// Global access to currently active lexer.
+// FIXME -- to be removed after more parser+lexer refactoring.
+octave_lexer *CURR_LEXER = 0;
+
+#if defined (GNULIB_NAMESPACE)
+// Calls to the following functions appear in the generated output from
+// Bison without the namespace tag.  Redefine them so we will use them
+// via the gnulib namespace.
+#define fclose GNULIB_NAMESPACE::fclose
+#define fprintf GNULIB_NAMESPACE::fprintf
+#define malloc GNULIB_NAMESPACE::malloc
+#endif
+
+// Buffer for help text snagged from function files.
+std::stack<std::string> help_buf;
+
+// TRUE means we are using readline.
+// (--no-line-editing)
+bool line_editing = true;
+
+// TRUE means we printed messages about reading startup files.
+bool reading_startup_message_printed = false;
+
+// TRUE means input is coming from startup file.
+bool input_from_startup_file = false;
+
+// Keep track of symbol table information when parsing functions.
+symtab_context parser_symtab_context;
+
+// List of autoloads (function -> file mapping).
+static std::map<std::string, std::string> autoload_map;
+
+// Forward declarations for some functions defined at the bottom of
+// the file.
+
+static void yyerror (octave_parser *curr_parser, const char *s);
+
+// Finish building a statement.
+template <class T>
+static tree_statement *
+make_statement (T *arg)
+{
+  octave_comment_list *comment = octave_comment_buffer::get_comment ();
+
+  return new tree_statement (arg, comment);
+}
+
+#define ABORT_PARSE \
+  do \
+    { \
+      global_command = 0; \
+      yyerrok; \
+      if (! parser_symtab_context.empty ()) \
+        parser_symtab_context.pop (); \
+      if ((interactive || forced_interactive)   \
+          && ! get_input_from_eval_string)      \
+        YYACCEPT; \
+      else \
+        YYABORT; \
+    } \
+  while (0)
+
+#define curr_lexer curr_parser->curr_lexer
+#define scanner curr_lexer->scanner
+
+%}
+
+// Bison declarations.
+
+// Don't add spaces around the = here; it causes some versions of
+// bison to fail to properly recognize the directive.
+
+%name-prefix="octave_"
+
+// We are using the pure parser interface and the reentrant lexer
+// interface but the Octave parser and lexer are NOT properly
+// reentrant because both still use many global variables.  It should be
+// safe to create a parser object and call it while anotehr parser
+// object is active (to parse a callback function while the main
+// interactive parser is waiting for input, for example) if you take
+// care to properly save and restore (typically with an unwind_protect
+// object) relevant global values before and after the nested call.
+
+%define api.pure
+%PUSH_PULL_DECL%
+%parse-param { octave_parser *curr_parser }
+%lex-param { void *scanner }
+
+%union
+{
+  // The type of the basic tokens returned by the lexer.
+  token *tok_val;
+
+  // Comment strings that we need to deal with mid-rule.
+  octave_comment_list *comment_type;
+
+  // Types for the nonterminals we generate.
+  char sep_type;
+  tree *tree_type;
+  tree_matrix *tree_matrix_type;
+  tree_cell *tree_cell_type;
+  tree_expression *tree_expression_type;
+  tree_constant *tree_constant_type;
+  tree_fcn_handle *tree_fcn_handle_type;
+  tree_anon_fcn_handle *tree_anon_fcn_handle_type;
+  tree_identifier *tree_identifier_type;
+  tree_index_expression *tree_index_expression_type;
+  tree_colon_expression *tree_colon_expression_type;
+  tree_argument_list *tree_argument_list_type;
+  tree_parameter_list *tree_parameter_list_type;
+  tree_command *tree_command_type;
+  tree_if_command *tree_if_command_type;
+  tree_if_clause *tree_if_clause_type;
+  tree_if_command_list *tree_if_command_list_type;
+  tree_switch_command *tree_switch_command_type;
+  tree_switch_case *tree_switch_case_type;
+  tree_switch_case_list *tree_switch_case_list_type;
+  tree_decl_elt *tree_decl_elt_type;
+  tree_decl_init_list *tree_decl_init_list_type;
+  tree_decl_command *tree_decl_command_type;
+  tree_statement *tree_statement_type;
+  tree_statement_list *tree_statement_list_type;
+  octave_user_function *octave_user_function_type;
+  void *dummy_type;
+}
+
+// Tokens with line and column information.
+%token <tok_val> '=' ':' '-' '+' '*' '/'
+%token <tok_val> ADD_EQ SUB_EQ MUL_EQ DIV_EQ LEFTDIV_EQ POW_EQ
+%token <tok_val> EMUL_EQ EDIV_EQ ELEFTDIV_EQ EPOW_EQ AND_EQ OR_EQ
+%token <tok_val> LSHIFT_EQ RSHIFT_EQ LSHIFT RSHIFT
+%token <tok_val> EXPR_AND_AND EXPR_OR_OR
+%token <tok_val> EXPR_AND EXPR_OR EXPR_NOT
+%token <tok_val> EXPR_LT EXPR_LE EXPR_EQ EXPR_NE EXPR_GE EXPR_GT
+%token <tok_val> LEFTDIV EMUL EDIV ELEFTDIV EPLUS EMINUS
+%token <tok_val> QUOTE TRANSPOSE
+%token <tok_val> PLUS_PLUS MINUS_MINUS POW EPOW
+%token <tok_val> NUM IMAG_NUM
+%token <tok_val> STRUCT_ELT
+%token <tok_val> NAME
+%token <tok_val> END
+%token <tok_val> DQ_STRING SQ_STRING
+%token <tok_val> FOR PARFOR WHILE DO UNTIL
+%token <tok_val> IF ELSEIF ELSE
+%token <tok_val> SWITCH CASE OTHERWISE
+%token <tok_val> BREAK CONTINUE FUNC_RET
+%token <tok_val> UNWIND CLEANUP
+%token <tok_val> TRY CATCH
+%token <tok_val> GLOBAL PERSISTENT
+%token <tok_val> FCN_HANDLE
+%token <tok_val> PROPERTIES METHODS EVENTS ENUMERATION
+%token <tok_val> METAQUERY
+%token <tok_val> SUPERCLASSREF
+%token <tok_val> GET SET
+
+// Other tokens.
+%token END_OF_INPUT LEXICAL_ERROR
+%token FCN SCRIPT_FILE FUNCTION_FILE CLASSDEF
+// %token VARARGIN VARARGOUT
+%token CLOSE_BRACE
+
+// Nonterminals we construct.
+%type <comment_type> stash_comment function_beg classdef_beg
+%type <comment_type> properties_beg methods_beg events_beg enum_beg
+%type <sep_type> sep_no_nl opt_sep_no_nl sep opt_sep opt_comma
+%type <tree_type> input
+%type <tree_constant_type> string constant magic_colon
+%type <tree_anon_fcn_handle_type> anon_fcn_handle
+%type <tree_fcn_handle_type> fcn_handle
+%type <tree_matrix_type> matrix_rows matrix_rows1
+%type <tree_cell_type> cell_rows cell_rows1
+%type <tree_expression_type> matrix cell
+%type <tree_expression_type> primary_expr oper_expr
+%type <tree_expression_type> simple_expr colon_expr assign_expr expression
+%type <tree_identifier_type> identifier fcn_name magic_tilde
+%type <tree_identifier_type> superclass_identifier meta_identifier
+%type <octave_user_function_type> function1 function2 classdef1
+%type <tree_index_expression_type> word_list_cmd
+%type <tree_colon_expression_type> colon_expr1
+%type <tree_argument_list_type> arg_list word_list assign_lhs
+%type <tree_argument_list_type> cell_or_matrix_row
+%type <tree_parameter_list_type> param_list param_list1 param_list2
+%type <tree_parameter_list_type> return_list return_list1
+%type <tree_parameter_list_type> superclasses opt_superclasses
+%type <tree_command_type> command select_command loop_command
+%type <tree_command_type> jump_command except_command function
+%type <tree_command_type> script_file classdef
+%type <tree_command_type> function_file function_list
+%type <tree_if_command_type> if_command
+%type <tree_if_clause_type> elseif_clause else_clause
+%type <tree_if_command_list_type> if_cmd_list1 if_cmd_list
+%type <tree_switch_command_type> switch_command
+%type <tree_switch_case_type> switch_case default_case
+%type <tree_switch_case_list_type> case_list1 case_list
+%type <tree_decl_elt_type> decl2
+%type <tree_decl_init_list_type> decl1
+%type <tree_decl_command_type> declaration
+%type <tree_statement_type> statement function_end classdef_end
+%type <tree_statement_list_type> simple_list simple_list1 list list1
+%type <tree_statement_list_type> opt_list input1
+// These types need to be specified.
+%type <dummy_type> attr
+%type <dummy_type> class_event
+%type <dummy_type> class_enum
+%type <dummy_type> class_property
+%type <dummy_type> properties_list
+%type <dummy_type> properties_block
+%type <dummy_type> methods_list
+%type <dummy_type> methods_block
+%type <dummy_type> opt_attr_list
+%type <dummy_type> attr_list
+%type <dummy_type> events_list
+%type <dummy_type> events_block
+%type <dummy_type> enum_list
+%type <dummy_type> enum_block
+%type <dummy_type> class_body
+
+// Precedence and associativity.
+%right '=' ADD_EQ SUB_EQ MUL_EQ DIV_EQ LEFTDIV_EQ POW_EQ EMUL_EQ EDIV_EQ ELEFTDIV_EQ EPOW_EQ OR_EQ AND_EQ LSHIFT_EQ RSHIFT_EQ
+%left EXPR_OR_OR
+%left EXPR_AND_AND
+%left EXPR_OR
+%left EXPR_AND
+%left EXPR_LT EXPR_LE EXPR_EQ EXPR_NE EXPR_GE EXPR_GT
+%left LSHIFT RSHIFT
+%left ':'
+%left '-' '+' EPLUS EMINUS
+%left '*' '/' LEFTDIV EMUL EDIV ELEFTDIV
+%right UNARY EXPR_NOT
+%left POW EPOW QUOTE TRANSPOSE
+%right PLUS_PLUS MINUS_MINUS
+%left '(' '.' '{'
+
+// Where to start.
+%start input
+
+%%
+
+// ==============================
+// Statements and statement lists
+// ==============================
+
+input           : input1
+                  {
+                    global_command = $1;
+                    promptflag = 1;
+                    YYACCEPT;
+                  }
+                | function_file
+                  { YYACCEPT; }
+                | simple_list parse_error
+                  { ABORT_PARSE; }
+                | parse_error
+                  { ABORT_PARSE; }
+                ;
+
+input1          : '\n'
+                  { $$ = 0; }
+                | END_OF_INPUT
+                  {
+                    curr_lexer->end_of_input = true;
+                    $$ = 0;
+                  }
+                | simple_list
+                  { $$ = $1; }
+                | simple_list '\n'
+                  { $$ = $1; }
+                | simple_list END_OF_INPUT
+                  { $$ = $1; }
+                ;
+
+simple_list     : simple_list1 opt_sep_no_nl
+                  { $$ = curr_parser->set_stmt_print_flag ($1, $2, false); }
+                ;
+
+simple_list1    : statement
+                  { $$ = curr_parser->make_statement_list ($1); }
+                | simple_list1 sep_no_nl statement
+                  { $$ = curr_parser->append_statement_list ($1, $2, $3, false); }
+                ;
+
+opt_list        : // empty
+                  { $$ = new tree_statement_list (); }
+                | list
+                  { $$ = $1; }
+                ;
+
+list            : list1 opt_sep
+                  { $$ = curr_parser->set_stmt_print_flag ($1, $2, true); }
+                ;
+
+list1           : statement
+                  { $$ = curr_parser->make_statement_list ($1); }
+                | list1 sep statement
+                  { $$ = curr_parser->append_statement_list ($1, $2, $3, true); }
+                ;
+
+statement       : expression
+                  { $$ = make_statement ($1); }
+                | command
+                  { $$ = make_statement ($1); }
+                | word_list_cmd
+                  { $$ = make_statement ($1); }
+                ;
+
+// =================
+// Word-list command
+// =================
+
+// These are not really like expressions since they can't appear on
+// the RHS of an assignment.  But they are also not like commands (IF,
+// WHILE, etc.
+
+word_list_cmd   : identifier word_list
+                  { $$ = curr_parser->make_index_expression ($1, $2, '('); }
+                ;
+
+word_list       : string
+                  { $$ = new tree_argument_list ($1); }
+                | word_list string
+                  {
+                    $1->append ($2);
+                    $$ = $1;
+                  }
+                ;
+
+// ===========
+// Expressions
+// ===========
+
+identifier      : NAME
+                  {
+                    symbol_table::symbol_record *sr = $1->sym_rec ();
+                    $$ = new tree_identifier (*sr, $1->line (), $1->column ());
+                  }
+                ;
+
+superclass_identifier
+                : SUPERCLASSREF
+                  { $$ = new tree_identifier ($1->line (), $1->column ()); }
+                ;
+
+meta_identifier : METAQUERY
+                  { $$ = new tree_identifier ($1->line (), $1->column ()); }
+                ;
+
+string          : DQ_STRING
+                  { $$ = curr_parser->make_constant (DQ_STRING, $1); }
+                | SQ_STRING
+                  { $$ = curr_parser->make_constant (SQ_STRING, $1); }
+                ;
+
+constant        : NUM
+                  { $$ = curr_parser->make_constant (NUM, $1); }
+                | IMAG_NUM
+                  { $$ = curr_parser->make_constant (IMAG_NUM, $1); }
+                | string
+                  { $$ = $1; }
+                ;
+
+matrix          : '[' ']'
+                  {
+                    $$ = new tree_constant (octave_null_matrix::instance);
+                    curr_lexer->looking_at_matrix_or_assign_lhs = false;
+                    curr_lexer->pending_local_variables.clear ();
+                  }
+                | '[' ';' ']'
+                  {
+                    $$ = new tree_constant (octave_null_matrix::instance);
+                    curr_lexer->looking_at_matrix_or_assign_lhs = false;
+                    curr_lexer->pending_local_variables.clear ();
+                  }
+                | '[' ',' ']'
+                  {
+                    $$ = new tree_constant (octave_null_matrix::instance);
+                    curr_lexer->looking_at_matrix_or_assign_lhs = false;
+                    curr_lexer->pending_local_variables.clear ();
+                  }
+                | '[' matrix_rows ']'
+                  {
+                    $$ = curr_parser->finish_matrix ($2);
+                    curr_lexer->looking_at_matrix_or_assign_lhs = false;
+                    curr_lexer->pending_local_variables.clear ();
+                  }
+                ;
+
+matrix_rows     : matrix_rows1
+                  { $$ = $1; }
+                | matrix_rows1 ';'      // Ignore trailing semicolon.
+                  { $$ = $1; }
+                ;
+
+matrix_rows1    : cell_or_matrix_row
+                  { $$ = new tree_matrix ($1); }
+                | matrix_rows1 ';' cell_or_matrix_row
+                  {
+                    $1->append ($3);
+                    $$ = $1;
+                  }
+                ;
+
+cell            : '{' '}'
+                  { $$ = new tree_constant (octave_value (Cell ())); }
+                | '{' ';' '}'
+                  { $$ = new tree_constant (octave_value (Cell ())); }
+                | '{' cell_rows '}'
+                  { $$ = curr_parser->finish_cell ($2); }
+                ;
+
+cell_rows       : cell_rows1
+                  { $$ = $1; }
+                | cell_rows1 ';'        // Ignore trailing semicolon.
+                  { $$ = $1; }
+                ;
+
+cell_rows1      : cell_or_matrix_row
+                  { $$ = new tree_cell ($1); }
+                | cell_rows1 ';' cell_or_matrix_row
+                  {
+                    $1->append ($3);
+                    $$ = $1;
+                  }
+                ;
+
+cell_or_matrix_row
+                : arg_list
+                  { $$ = curr_parser->validate_matrix_row ($1); }
+                | arg_list ','  // Ignore trailing comma.
+                  { $$ = curr_parser->validate_matrix_row ($1); }
+                ;
+
+fcn_handle      : '@' FCN_HANDLE
+                  {
+                    $$ = curr_parser->make_fcn_handle ($2);
+                    curr_lexer->looking_at_function_handle--;
+                  }
+                ;
+
+anon_fcn_handle : '@' param_list statement
+                  {
+                    curr_lexer->quote_is_transpose = false;
+                    $$ = curr_parser->make_anon_fcn_handle ($2, $3);
+                  }
+                ;
+
+primary_expr    : identifier
+                  { $$ = $1; }
+                | constant
+                  { $$ = $1; }
+                | fcn_handle
+                  { $$ = $1; }
+                | matrix
+                  { $$ = $1; }
+                | cell
+                  { $$ = $1; }
+                | meta_identifier
+                  { $$ = $1; }
+                | superclass_identifier
+                  { $$ = $1; }
+                | '(' expression ')'
+                  { $$ = $2->mark_in_parens (); }
+                ;
+
+magic_colon     : ':'
+                  {
+                    octave_value tmp (octave_value::magic_colon_t);
+                    $$ = new tree_constant (tmp);
+                  }
+                ;
+
+magic_tilde     : EXPR_NOT
+                  {
+                    $$ = new tree_black_hole ();
+                  }
+                ;
+
+arg_list        : expression
+                  { $$ = new tree_argument_list ($1); }
+                | magic_colon
+                  { $$ = new tree_argument_list ($1); }
+                | magic_tilde
+                  { $$ = new tree_argument_list ($1); }
+                | arg_list ',' magic_colon
+                  {
+                    $1->append ($3);
+                    $$ = $1;
+                  }
+                | arg_list ',' magic_tilde
+                  {
+                    $1->append ($3);
+                    $$ = $1;
+                  }
+                | arg_list ',' expression
+                  {
+                    $1->append ($3);
+                    $$ = $1;
+                  }
+                ;
+
+indirect_ref_op : '.'
+                  { curr_lexer->looking_at_indirect_ref = true; }
+                ;
+
+oper_expr       : primary_expr
+                  { $$ = $1; }
+                | oper_expr PLUS_PLUS
+                  { $$ = curr_parser->make_postfix_op (PLUS_PLUS, $1, $2); }
+                | oper_expr MINUS_MINUS
+                  { $$ = curr_parser->make_postfix_op (MINUS_MINUS, $1, $2); }
+                | oper_expr '(' ')'
+                  { $$ = curr_parser->make_index_expression ($1, 0, '('); }
+                | oper_expr '(' arg_list ')'
+                  { $$ = curr_parser->make_index_expression ($1, $3, '('); }
+                | oper_expr '{' '}'
+                  { $$ = curr_parser->make_index_expression ($1, 0, '{'); }
+                | oper_expr '{' arg_list '}'
+                  { $$ = curr_parser->make_index_expression ($1, $3, '{'); }
+                | oper_expr QUOTE
+                  { $$ = curr_parser->make_postfix_op (QUOTE, $1, $2); }
+                | oper_expr TRANSPOSE
+                  { $$ = curr_parser->make_postfix_op (TRANSPOSE, $1, $2); }
+                | oper_expr indirect_ref_op STRUCT_ELT
+                  { $$ = curr_parser->make_indirect_ref ($1, $3->text ()); }
+                | oper_expr indirect_ref_op '(' expression ')'
+                  { $$ = curr_parser->make_indirect_ref ($1, $4); }
+                | PLUS_PLUS oper_expr %prec UNARY
+                  { $$ = curr_parser->make_prefix_op (PLUS_PLUS, $2, $1); }
+                | MINUS_MINUS oper_expr %prec UNARY
+                  { $$ = curr_parser->make_prefix_op (MINUS_MINUS, $2, $1); }
+                | EXPR_NOT oper_expr %prec UNARY
+                  { $$ = curr_parser->make_prefix_op (EXPR_NOT, $2, $1); }
+                | '+' oper_expr %prec UNARY
+                  { $$ = curr_parser->make_prefix_op ('+', $2, $1); }
+                | '-' oper_expr %prec UNARY
+                  { $$ = curr_parser->make_prefix_op ('-', $2, $1); }
+                | oper_expr POW oper_expr
+                  { $$ = curr_parser->make_binary_op (POW, $1, $2, $3); }
+                | oper_expr EPOW oper_expr
+                  { $$ = curr_parser->make_binary_op (EPOW, $1, $2, $3); }
+                | oper_expr '+' oper_expr
+                  { $$ = curr_parser->make_binary_op ('+', $1, $2, $3); }
+                | oper_expr '-' oper_expr
+                  { $$ = curr_parser->make_binary_op ('-', $1, $2, $3); }
+                | oper_expr '*' oper_expr
+                  { $$ = curr_parser->make_binary_op ('*', $1, $2, $3); }
+                | oper_expr '/' oper_expr
+                  { $$ = curr_parser->make_binary_op ('/', $1, $2, $3); }
+                | oper_expr EPLUS oper_expr
+                  { $$ = curr_parser->make_binary_op ('+', $1, $2, $3); }
+                | oper_expr EMINUS oper_expr
+                  { $$ = curr_parser->make_binary_op ('-', $1, $2, $3); }
+                | oper_expr EMUL oper_expr
+                  { $$ = curr_parser->make_binary_op (EMUL, $1, $2, $3); }
+                | oper_expr EDIV oper_expr
+                  { $$ = curr_parser->make_binary_op (EDIV, $1, $2, $3); }
+                | oper_expr LEFTDIV oper_expr
+                  { $$ = curr_parser->make_binary_op (LEFTDIV, $1, $2, $3); }
+                | oper_expr ELEFTDIV oper_expr
+                  { $$ = curr_parser->make_binary_op (ELEFTDIV, $1, $2, $3); }
+                ;
+
+colon_expr      : colon_expr1
+                  { $$ = curr_parser->finish_colon_expression ($1); }
+                ;
+
+colon_expr1     : oper_expr
+                  { $$ = new tree_colon_expression ($1); }
+                | colon_expr1 ':' oper_expr
+                  {
+                    if (! ($$ = $1->append ($3)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+simple_expr     : colon_expr
+                  { $$ = $1; }
+                | simple_expr LSHIFT simple_expr
+                  { $$ = curr_parser->make_binary_op (LSHIFT, $1, $2, $3); }
+                | simple_expr RSHIFT simple_expr
+                  { $$ = curr_parser->make_binary_op (RSHIFT, $1, $2, $3); }
+                | simple_expr EXPR_LT simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_LT, $1, $2, $3); }
+                | simple_expr EXPR_LE simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_LE, $1, $2, $3); }
+                | simple_expr EXPR_EQ simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_EQ, $1, $2, $3); }
+                | simple_expr EXPR_GE simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_GE, $1, $2, $3); }
+                | simple_expr EXPR_GT simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_GT, $1, $2, $3); }
+                | simple_expr EXPR_NE simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_NE, $1, $2, $3); }
+                | simple_expr EXPR_AND simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_AND, $1, $2, $3); }
+                | simple_expr EXPR_OR simple_expr
+                  { $$ = curr_parser->make_binary_op (EXPR_OR, $1, $2, $3); }
+                | simple_expr EXPR_AND_AND simple_expr
+                  { $$ = curr_parser->make_boolean_op (EXPR_AND_AND, $1, $2, $3); }
+                | simple_expr EXPR_OR_OR simple_expr
+                  { $$ = curr_parser->make_boolean_op (EXPR_OR_OR, $1, $2, $3); }
+                ;
+
+// Arrange for the lexer to return CLOSE_BRACE for ']' by looking ahead
+// one token for an assignment op.
+
+assign_lhs      : simple_expr
+                  {
+                    $$ = new tree_argument_list ($1);
+                    $$->mark_as_simple_assign_lhs ();
+                  }
+                | '[' arg_list opt_comma CLOSE_BRACE
+                  {
+                    $$ = $2;
+                    curr_lexer->looking_at_matrix_or_assign_lhs = false;
+                    for (std::set<std::string>::const_iterator p = curr_lexer->pending_local_variables.begin ();
+                         p != curr_lexer->pending_local_variables.end ();
+                         p++)
+                      {
+                        symbol_table::force_variable (*p);
+                      }
+                    curr_lexer->pending_local_variables.clear ();
+                  }
+                ;
+
+assign_expr     : assign_lhs '=' expression
+                  { $$ = curr_parser->make_assign_op ('=', $1, $2, $3); }
+                | assign_lhs ADD_EQ expression
+                  { $$ = curr_parser->make_assign_op (ADD_EQ, $1, $2, $3); }
+                | assign_lhs SUB_EQ expression
+                  { $$ = curr_parser->make_assign_op (SUB_EQ, $1, $2, $3); }
+                | assign_lhs MUL_EQ expression
+                  { $$ = curr_parser->make_assign_op (MUL_EQ, $1, $2, $3); }
+                | assign_lhs DIV_EQ expression
+                  { $$ = curr_parser->make_assign_op (DIV_EQ, $1, $2, $3); }
+                | assign_lhs LEFTDIV_EQ expression
+                  { $$ = curr_parser->make_assign_op (LEFTDIV_EQ, $1, $2, $3); }
+                | assign_lhs POW_EQ expression
+                  { $$ = curr_parser->make_assign_op (POW_EQ, $1, $2, $3); }
+                | assign_lhs LSHIFT_EQ expression
+                  { $$ = curr_parser->make_assign_op (LSHIFT_EQ, $1, $2, $3); }
+                | assign_lhs RSHIFT_EQ expression
+                  { $$ = curr_parser->make_assign_op (RSHIFT_EQ, $1, $2, $3); }
+                | assign_lhs EMUL_EQ expression
+                  { $$ = curr_parser->make_assign_op (EMUL_EQ, $1, $2, $3); }
+                | assign_lhs EDIV_EQ expression
+                  { $$ = curr_parser->make_assign_op (EDIV_EQ, $1, $2, $3); }
+                | assign_lhs ELEFTDIV_EQ expression
+                  { $$ = curr_parser->make_assign_op (ELEFTDIV_EQ, $1, $2, $3); }
+                | assign_lhs EPOW_EQ expression
+                  { $$ = curr_parser->make_assign_op (EPOW_EQ, $1, $2, $3); }
+                | assign_lhs AND_EQ expression
+                  { $$ = curr_parser->make_assign_op (AND_EQ, $1, $2, $3); }
+                | assign_lhs OR_EQ expression
+                  { $$ = curr_parser->make_assign_op (OR_EQ, $1, $2, $3); }
+                ;
+
+expression      : simple_expr
+                  { $$ = $1; }
+                | assign_expr
+                  { $$ = $1; }
+                | anon_fcn_handle
+                  { $$ = $1; }
+                ;
+
+// ================================================
+// Commands, declarations, and function definitions
+// ================================================
+
+command         : declaration
+                  { $$ = $1; }
+                | select_command
+                  { $$ = $1; }
+                | loop_command
+                  { $$ = $1; }
+                | jump_command
+                  { $$ = $1; }
+                | except_command
+                  { $$ = $1; }
+                | function
+                  { $$ = $1; }
+                | script_file
+                  { $$ = $1; }
+                | classdef
+                  { $$ = $1; }
+                ;
+
+// =====================
+// Declaration statemnts
+// =====================
+
+parsing_decl_list
+                : // empty
+                  { curr_lexer->looking_at_decl_list = true; }
+
+declaration     : GLOBAL parsing_decl_list decl1
+                  {
+                    $$ = curr_parser->make_decl_command (GLOBAL, $1, $3);
+                    curr_lexer->looking_at_decl_list = false;
+                  }
+                | PERSISTENT parsing_decl_list decl1
+                  {
+                    $$ = curr_parser->make_decl_command (PERSISTENT, $1, $3);
+                    curr_lexer->looking_at_decl_list = false;
+                  }
+                ;
+
+decl1           : decl2
+                  { $$ = new tree_decl_init_list ($1); }
+                | decl1 decl2
+                  {
+                    $1->append ($2);
+                    $$ = $1;
+                  }
+                ;
+
+decl_param_init : // empty
+                { curr_lexer->looking_at_initializer_expression = true; }
+
+decl2           : identifier
+                  { $$ = new tree_decl_elt ($1); }
+                | identifier '=' decl_param_init expression
+                  {
+                    curr_lexer->looking_at_initializer_expression = false;
+                    $$ = new tree_decl_elt ($1, $4);
+                  }
+                | magic_tilde
+                  {
+                    $$ = new tree_decl_elt ($1);
+                  }
+                ;
+
+// ====================
+// Selection statements
+// ====================
+
+select_command  : if_command
+                  { $$ = $1; }
+                | switch_command
+                  { $$ = $1; }
+                ;
+
+// ============
+// If statement
+// ============
+
+if_command      : IF stash_comment if_cmd_list END
+                  {
+                    if (! ($$ = curr_parser->finish_if_command ($1, $3, $4, $2)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+if_cmd_list     : if_cmd_list1
+                  { $$ = $1; }
+                | if_cmd_list1 else_clause
+                  {
+                    $1->append ($2);
+                    $$ = $1;
+                  }
+                ;
+
+if_cmd_list1    : expression opt_sep opt_list
+                  {
+                    $1->mark_braindead_shortcircuit (curr_fcn_file_full_name);
+
+                    $$ = curr_parser->start_if_command ($1, $3);
+                  }
+                | if_cmd_list1 elseif_clause
+                  {
+                    $1->append ($2);
+                    $$ = $1;
+                  }
+                ;
+
+elseif_clause   : ELSEIF stash_comment opt_sep expression opt_sep opt_list
+                  {
+                    $4->mark_braindead_shortcircuit (curr_fcn_file_full_name);
+
+                    $$ = curr_parser->make_elseif_clause ($1, $4, $6, $2);
+                  }
+                ;
+
+else_clause     : ELSE stash_comment opt_sep opt_list
+                  { $$ = new tree_if_clause ($4, $2); }
+                ;
+
+// ================
+// Switch statement
+// ================
+
+switch_command  : SWITCH stash_comment expression opt_sep case_list END
+                  {
+                    if (! ($$ = curr_parser->finish_switch_command ($1, $3, $5, $6, $2)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+case_list       : // empty
+                  { $$ = new tree_switch_case_list (); }
+                | default_case
+                  { $$ = new tree_switch_case_list ($1); }
+                | case_list1
+                  { $$ = $1; }
+                | case_list1 default_case
+                  {
+                    $1->append ($2);
+                    $$ = $1;
+                  }
+                ;
+
+case_list1      : switch_case
+                  { $$ = new tree_switch_case_list ($1); }
+                | case_list1 switch_case
+                  {
+                    $1->append ($2);
+                    $$ = $1;
+                  }
+                ;
+
+switch_case     : CASE stash_comment opt_sep expression opt_sep opt_list
+                  { $$ = curr_parser->make_switch_case ($1, $4, $6, $2); }
+                ;
+
+default_case    : OTHERWISE stash_comment opt_sep opt_list
+                  {
+                    $$ = new tree_switch_case ($4, $2);
+                  }
+                ;
+
+// =======
+// Looping
+// =======
+
+loop_command    : WHILE stash_comment expression opt_sep opt_list END
+                  {
+                    $3->mark_braindead_shortcircuit (curr_fcn_file_full_name);
+
+                    if (! ($$ = curr_parser->make_while_command ($1, $3, $5, $6, $2)))
+                      ABORT_PARSE;
+                  }
+                | DO stash_comment opt_sep opt_list UNTIL expression
+                  {
+                    if (! ($$ = curr_parser->make_do_until_command ($5, $4, $6, $2)))
+                      ABORT_PARSE;
+                  }
+                | FOR stash_comment assign_lhs '=' expression opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_for_command (FOR, $1, $3, $5, 0,
+                                                  $7, $8, $2)))
+                      ABORT_PARSE;
+                  }
+                | FOR stash_comment '(' assign_lhs '=' expression ')' opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_for_command (FOR, $1, $4, $6, 0,
+                                                  $9, $10, $2)))
+                      ABORT_PARSE;
+                  }
+                | PARFOR stash_comment assign_lhs '=' expression opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_for_command (PARFOR, $1, $3, $5,
+                                                  0, $7, $8, $2)))
+                      ABORT_PARSE;
+                  }
+                | PARFOR stash_comment '(' assign_lhs '=' expression ',' expression ')' opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_for_command (PARFOR, $1, $4, $6,
+                                                  $8, $11, $12, $2)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+// =======
+// Jumping
+// =======
+
+jump_command    : BREAK
+                  {
+                    if (! ($$ = curr_parser->make_break_command ($1)))
+                      ABORT_PARSE;
+                  }
+                | CONTINUE
+                  {
+                    if (! ($$ = curr_parser->make_continue_command ($1)))
+                      ABORT_PARSE;
+                  }
+                | FUNC_RET
+                  {
+                    if (! ($$ = curr_parser->make_return_command ($1)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+// ==========
+// Exceptions
+// ==========
+
+except_command  : UNWIND stash_comment opt_sep opt_list CLEANUP
+                  stash_comment opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_unwind_command ($1, $4, $8, $9, $2, $6)))
+                      ABORT_PARSE;
+                  }
+                | TRY stash_comment opt_sep opt_list CATCH
+                  stash_comment opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_try_command ($1, $4, $8, $9, $2, $6)))
+                      ABORT_PARSE;
+                  }
+                | TRY stash_comment opt_sep opt_list END
+                  {
+                    if (! ($$ = curr_parser->make_try_command ($1, $4, 0, $5, $2, 0)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+// ===========================================
+// Some 'subroutines' for function definitions
+// ===========================================
+
+push_fcn_symtab : // empty
+                  {
+                    curr_parser->curr_fcn_depth++;
+
+                    if (curr_parser->max_fcn_depth < curr_parser->curr_fcn_depth)
+                      curr_parser->max_fcn_depth = curr_parser->curr_fcn_depth;
+
+                    parser_symtab_context.push ();
+
+                    symbol_table::set_scope (symbol_table::alloc_scope ());
+
+                    curr_parser->function_scopes.push_back (symbol_table::current_scope ());
+
+                    if (! reading_script_file && curr_parser->curr_fcn_depth == 1
+                        && ! curr_parser->parsing_subfunctions)
+                      curr_parser->primary_fcn_scope = symbol_table::current_scope ();
+
+                    if (reading_script_file && curr_parser->curr_fcn_depth > 1)
+                      curr_parser->bison_error ("nested functions not implemented in this context");
+                  }
+                ;
+
+// ===========================
+// List of function parameters
+// ===========================
+
+param_list_beg  : '('
+                  {
+                    curr_lexer->looking_at_parameter_list = true;
+
+                    if (curr_lexer->looking_at_function_handle)
+                      {
+                        parser_symtab_context.push ();
+                        symbol_table::set_scope (symbol_table::alloc_scope ());
+                        curr_lexer->looking_at_function_handle--;
+                        curr_lexer->looking_at_anon_fcn_args = true;
+                      }
+                  }
+                ;
+
+param_list_end  : ')'
+                  {
+                    curr_lexer->looking_at_parameter_list = false;
+                    curr_lexer->looking_for_object_index = false;
+                  }
+                ;
+
+param_list      : param_list_beg param_list1 param_list_end
+                  {
+                    curr_lexer->quote_is_transpose = false;
+                    $$ = $2;
+                  }
+                | param_list_beg error
+                  {
+                    curr_parser->bison_error ("invalid parameter list");
+                    $$ = 0;
+                    ABORT_PARSE;
+                  }
+                ;
+
+param_list1     : // empty
+                  { $$ = 0; }
+                | param_list2
+                  {
+                    $1->mark_as_formal_parameters ();
+                    if ($1->validate (tree_parameter_list::in))
+                      $$ = $1;
+                    else
+                      ABORT_PARSE;
+                  }
+                ;
+
+param_list2     : decl2
+                  { $$ = new tree_parameter_list ($1); }
+                | param_list2 ',' decl2
+                  {
+                    $1->append ($3);
+                    $$ = $1;
+                  }
+                ;
+
+// ===================================
+// List of function return value names
+// ===================================
+
+return_list     : '[' ']'
+                  {
+                    curr_lexer->looking_at_return_list = false;
+                    $$ = new tree_parameter_list ();
+                  }
+                | return_list1
+                  {
+                    curr_lexer->looking_at_return_list = false;
+                    if ($1->validate (tree_parameter_list::out))
+                      $$ = $1;
+                    else
+                      ABORT_PARSE;
+                  }
+                | '[' return_list1 ']'
+                  {
+                    curr_lexer->looking_at_return_list = false;
+                    if ($2->validate (tree_parameter_list::out))
+                      $$ = $2;
+                    else
+                      ABORT_PARSE;
+                  }
+                ;
+
+return_list1    : identifier
+                  { $$ = new tree_parameter_list (new tree_decl_elt ($1)); }
+                | return_list1 ',' identifier
+                  {
+                    $1->append (new tree_decl_elt ($3));
+                    $$ = $1;
+                  }
+                ;
+
+// ===========
+// Script file
+// ===========
+
+script_file     : SCRIPT_FILE opt_list END_OF_INPUT
+                  {
+                    tree_statement *end_of_script
+                      = curr_parser->make_end ("endscript",
+                                               curr_lexer->input_line_number,
+                                               curr_lexer->current_input_column);
+
+                    curr_parser->make_script ($2, end_of_script);
+
+                    $$ = 0;
+                  }
+                ;
+
+// =============
+// Function file
+// =============
+
+function_file   : FUNCTION_FILE function_list opt_sep END_OF_INPUT
+                  { $$ = 0; }
+                ;
+
+function_list   : function
+                | function_list sep function
+                ;
+
+// ===================
+// Function definition
+// ===================
+
+function_beg    : push_fcn_symtab FCN stash_comment
+                  {
+                    $$ = $3;
+
+                    if (reading_classdef_file || curr_lexer->parsing_classdef)
+                      curr_lexer->maybe_classdef_get_set_method = true;
+                  }
+                ;
+
+function        : function_beg function1
+                  {
+                    $$ = curr_parser->finish_function (0, $2, $1);
+                    curr_parser->recover_from_parsing_function ();
+                  }
+                | function_beg return_list '=' function1
+                  {
+                    $$ = curr_parser->finish_function ($2, $4, $1);
+                    curr_parser->recover_from_parsing_function ();
+                  }
+                ;
+
+fcn_name        : identifier
+                  {
+                    std::string id_name = $1->name ();
+
+                    curr_lexer->parsed_function_name.top () = true;
+                    curr_lexer->maybe_classdef_get_set_method = false;
+
+                    $$ = $1;
+                  }
+                | GET '.' identifier
+                  {
+                    curr_lexer->parsed_function_name.top () = true;
+                    curr_lexer->maybe_classdef_get_set_method = false;
+                    $$ = $3;
+                  }
+                | SET '.' identifier
+                  {
+                    curr_lexer->parsed_function_name.top () = true;
+                    curr_lexer->maybe_classdef_get_set_method = false;
+                    $$ = $3;
+                  }
+                ;
+
+function1       : fcn_name function2
+                  {
+                    std::string fname = $1->name ();
+
+                    delete $1;
+
+                    if (! ($$ = curr_parser->frob_function (fname, $2)))
+                      ABORT_PARSE;
+                  }
+                ;
+
+function2       : param_list opt_sep opt_list function_end
+                  { $$ = curr_parser->start_function ($1, $3, $4); }
+                | opt_sep opt_list function_end
+                  { $$ = curr_parser->start_function (0, $2, $3); }
+                ;
+
+function_end    : END
+                  {
+                    curr_parser->endfunction_found = true;
+                    if (curr_parser->end_token_ok ($1, token::function_end))
+                      $$ = curr_parser->make_end ("endfunction", $1->line (), $1->column ());
+                    else
+                      ABORT_PARSE;
+                  }
+                | END_OF_INPUT
+                  {
+// A lot of tests are based on the assumption that this is OK
+//                  if (reading_script_file)
+//                    {
+//                      curr_parser->bison_error ("function body open at end of script");
+//                      YYABORT;
+//                    }
+
+                    if (curr_parser->endfunction_found)
+                      {
+                        curr_parser->bison_error ("inconsistent function endings -- "
+                                 "if one function is explicitly ended, "
+                                 "so must all the others");
+                        YYABORT;
+                      }
+
+                    if (! (reading_fcn_file || reading_script_file
+                           || get_input_from_eval_string))
+                      {
+                        curr_parser->bison_error ("function body open at end of input");
+                        YYABORT;
+                      }
+
+                    if (reading_classdef_file)
+                      {
+                        curr_parser->bison_error ("classdef body open at end of input");
+                        YYABORT;
+                      }
+
+                    $$ = curr_parser->make_end ("endfunction",
+                                                curr_lexer->input_line_number,
+                                                curr_lexer->current_input_column);
+                  }
+                ;
+
+// ========
+// Classdef
+// ========
+
+classdef_beg    : CLASSDEF stash_comment
+                  {
+                    $$ = 0;
+                    curr_lexer->parsing_classdef = true;
+                  }
+                ;
+
+classdef_end    : END
+                  {
+                    curr_lexer->parsing_classdef = false;
+
+                    if (curr_parser->end_token_ok ($1, token::classdef_end))
+                      $$ = curr_parser->make_end ("endclassdef", $1->line (), $1->column ());
+                    else
+                      ABORT_PARSE;
+                  }
+                ;
+
+classdef1       : classdef_beg opt_attr_list identifier opt_superclasses
+                  { $$ = 0; }
+                ;
+
+classdef        : classdef1 opt_sep class_body opt_sep stash_comment classdef_end
+                  { $$ = 0; }
+                ;
+
+opt_attr_list   : // empty
+                  { $$ = 0; }
+                | '(' attr_list ')'
+                  { $$ = 0; }
+                ;
+
+attr_list       : attr
+                  { $$ = 0; }
+                | attr_list ',' attr
+                  { $$ = 0; }
+                ;
+
+attr            : identifier
+                  { $$ = 0; }
+                | identifier '=' decl_param_init expression
+                  { $$ = 0; }
+                | EXPR_NOT identifier
+                  { $$ = 0; }
+                ;
+
+opt_superclasses
+                : // empty
+                  { $$ = 0; }
+                | superclasses
+                  { $$ = 0; }
+                ;
+
+superclasses    : EXPR_LT identifier '.' identifier
+                  { $$ = 0; }
+                | EXPR_LT identifier
+                  { $$ = 0; }
+                | superclasses EXPR_AND identifier '.' identifier
+                  { $$ = 0; }
+                | superclasses EXPR_AND identifier
+                  { $$ = 0; }
+                ;
+
+class_body      : properties_block
+                  { $$ = 0; }
+                | methods_block
+                  { $$ = 0; }
+                | events_block
+                  { $$ = 0; }
+                | enum_block
+                  { $$ = 0; }
+                | class_body opt_sep properties_block
+                  { $$ = 0; }
+                | class_body opt_sep methods_block
+                  { $$ = 0; }
+                | class_body opt_sep events_block
+                  { $$ = 0; }
+                | class_body opt_sep enum_block
+                  { $$ = 0; }
+                ;
+
+properties_beg  : PROPERTIES stash_comment
+                  { $$ = 0; }
+                ;
+
+properties_block
+                : properties_beg opt_attr_list opt_sep properties_list opt_sep END
+                  { $$ = 0; }
+                ;
+
+properties_list
+                : class_property
+                  { $$ = 0; }
+                | properties_list opt_sep class_property
+                  { $$ = 0; }
+                ;
+
+class_property  : identifier
+                  { $$ = 0; }
+                | identifier '=' decl_param_init expression ';'
+                  { $$ = 0; }
+                ;
+
+methods_beg     : METHODS stash_comment
+                  { $$ = 0; }
+                ;
+
+methods_block   : methods_beg opt_attr_list opt_sep methods_list opt_sep END
+                  { $$ = 0; }
+                ;
+
+methods_list    : function
+                  { $$ = 0; }
+                | methods_list opt_sep function
+                  { $$ = 0; }
+                ;
+
+events_beg      : EVENTS stash_comment
+                  { $$ = 0; }
+                ;
+
+events_block    : events_beg opt_attr_list opt_sep events_list opt_sep END
+                  { $$ = 0; }
+                ;
+
+events_list     : class_event
+                  { $$ = 0; }
+                | events_list opt_sep class_event
+                  { $$ = 0; }
+                ;
+
+class_event     : identifier
+                  { $$ = 0; }
+                ;
+
+enum_beg        : ENUMERATION stash_comment
+                  { $$ = 0; }
+                ;
+
+enum_block      : enum_beg opt_attr_list opt_sep enum_list opt_sep END
+                  { $$ = 0; }
+                ;
+
+enum_list       : class_enum
+                  { $$ = 0; }
+                | enum_list opt_sep class_enum
+                  { $$ = 0; }
+                ;
+
+class_enum      : identifier '(' expression ')'
+                  { $$ = 0; }
+                ;
+
+// =============
+// Miscellaneous
+// =============
+
+stash_comment   : // empty
+                  { $$ = octave_comment_buffer::get_comment (); }
+                ;
+
+parse_error     : LEXICAL_ERROR
+                  { curr_parser->bison_error ("parse error"); }
+                | error
+                ;
+
+sep_no_nl       : ','
+                  { $$ = ','; }
+                | ';'
+                  { $$ = ';'; }
+                | sep_no_nl ','
+                  { $$ = $1; }
+                | sep_no_nl ';'
+                  { $$ = $1; }
+                ;
+
+opt_sep_no_nl   : // empty
+                  { $$ = 0; }
+                | sep_no_nl
+                  { $$ = $1; }
+                ;
+
+sep             : ','
+                  { $$ = ','; }
+                | ';'
+                  { $$ = ';'; }
+                | '\n'
+                  { $$ = '\n'; }
+                | sep ','
+                  { $$ = $1; }
+                | sep ';'
+                  { $$ = $1; }
+                | sep '\n'
+                  { $$ = $1; }
+                ;
+
+opt_sep         : // empty
+                  { $$ = 0; }
+                | sep
+                  { $$ = $1; }
+                ;
+
+opt_comma       : // empty
+                  { $$ = 0; }
+                | ','
+                  { $$ = ','; }
+                ;
+
+%%
+
+// Generic error messages.
+
+#undef curr_lexer
+
+static void
+yyerror (octave_parser *curr_parser, const char *s)
+{
+  curr_parser->bison_error (s);
+}
+
+octave_parser::~octave_parser (void)
+{
+#if defined (OCTAVE_USE_PUSH_PARSER)
+  yypstate_delete (static_cast<yypstate *> (parser_state));
+#endif
+
+delete curr_lexer;
+}
+void octave_parser::init (void)
+{
+#if defined (OCTAVE_USE_PUSH_PARSER)
+  parser_state = yypstate_new ();
+#endif
+
+  CURR_LEXER = curr_lexer;
+}
+
+int
+octave_parser::run (void)
+{
+  int status = 0;
+
+#if defined (OCTAVE_USE_PUSH_PARSER)
+
+  do
+    {
+      YYSTYPE lval;
+
+      int token = octave_lex (&lval, scanner);
+
+      yypstate *pstate = static_cast<yypstate *> (parser_state);
+
+      status = octave_push_parse (pstate, token, &lval, this);
+    }
+  while (status == YYPUSH_MORE);
+
+#else
+
+  status = octave_parse (this);
+
+#endif
+
+  return status;
+}
+
+// Error mesages for mismatched end tokens.
+
+void
+octave_parser::end_error (const char *type, token::end_tok_type ettype,
+                          int l, int c)
+{
+  static const char *fmt
+    = "'%s' command matched by '%s' near line %d column %d";
+
+  switch (ettype)
+    {
+    case token::simple_end:
+      error (fmt, type, "end", l, c);
+      break;
+
+    case token::for_end:
+      error (fmt, type, "endfor", l, c);
+      break;
+
+    case token::function_end:
+      error (fmt, type, "endfunction", l, c);
+      break;
+
+    case token::classdef_end:
+      error (fmt, type, "endclassdef", l, c);
+      break;
+
+    case token::if_end:
+      error (fmt, type, "endif", l, c);
+      break;
+
+    case token::switch_end:
+      error (fmt, type, "endswitch", l, c);
+      break;
+
+    case token::while_end:
+      error (fmt, type, "endwhile", l, c);
+      break;
+
+    case token::try_catch_end:
+      error (fmt, type, "end_try_catch", l, c);
+      break;
+
+    case token::unwind_protect_end:
+      error (fmt, type, "end_unwind_protect", l, c);
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+}
+
+// Check to see that end tokens are properly matched.
+
+bool
+octave_parser::end_token_ok (token *tok, token::end_tok_type expected)
+{
+  bool retval = true;
+
+  token::end_tok_type ettype = tok->ettype ();
+
+  if (ettype != expected && ettype != token::simple_end)
+    {
+      retval = false;
+
+      bison_error ("parse error");
+
+      int l = tok->line ();
+      int c = tok->column ();
+
+      switch (expected)
+        {
+        case token::classdef_end:
+          end_error ("classdef", ettype, l, c);
+          break;
+
+        case token::for_end:
+          end_error ("for", ettype, l, c);
+          break;
+
+        case token::enumeration_end:
+          end_error ("enumeration", ettype, l, c);
+          break;
+
+        case token::function_end:
+          end_error ("function", ettype, l, c);
+          break;
+
+        case token::if_end:
+          end_error ("if", ettype, l, c);
+          break;
+
+        case token::parfor_end:
+          end_error ("parfor", ettype, l, c);
+          break;
+
+        case token::try_catch_end:
+          end_error ("try", ettype, l, c);
+          break;
+
+        case token::switch_end:
+          end_error ("switch", ettype, l, c);
+          break;
+
+        case token::unwind_protect_end:
+          end_error ("unwind_protect", ettype, l, c);
+          break;
+
+        case token::while_end:
+          end_error ("while", ettype, l, c);
+          break;
+
+        default:
+          panic_impossible ();
+          break;
+        }
+    }
+
+  return retval;
+}
+
+// Maybe print a warning if an assignment expression is used as the
+// test in a logical expression.
+
+void
+octave_parser::maybe_warn_assign_as_truth_value (tree_expression *expr)
+{
+  if (expr->is_assignment_expression ()
+      && expr->paren_count () < 2)
+    {
+      if (curr_fcn_file_full_name.empty ())
+        warning_with_id
+          ("Octave:assign-as-truth-value",
+           "suggest parenthesis around assignment used as truth value");
+      else
+        warning_with_id
+          ("Octave:assign-as-truth-value",
+           "suggest parenthesis around assignment used as truth value near line %d, column %d in file '%s'",
+           expr->line (), expr->column (), curr_fcn_file_full_name.c_str ());
+    }
+}
+
+// Maybe print a warning about switch labels that aren't constants.
+
+void
+octave_parser::maybe_warn_variable_switch_label (tree_expression *expr)
+{
+  if (! expr->is_constant ())
+    {
+      if (curr_fcn_file_full_name.empty ())
+        warning_with_id ("Octave:variable-switch-label",
+                         "variable switch label");
+      else
+        warning_with_id
+          ("Octave:variable-switch-label",
+           "variable switch label near line %d, column %d in file '%s'",
+           expr->line (), expr->column (), curr_fcn_file_full_name.c_str ());
+    }
+}
+
+static tree_expression *
+fold (tree_binary_expression *e)
+{
+  tree_expression *retval = e;
+
+  unwind_protect frame;
+
+  frame.protect_var (error_state);
+  frame.protect_var (warning_state);
+
+  frame.protect_var (discard_error_messages);
+  frame.protect_var (discard_warning_messages);
+
+  discard_error_messages = true;
+  discard_warning_messages = true;
+
+  tree_expression *op1 = e->lhs ();
+  tree_expression *op2 = e->rhs ();
+
+  if (op1->is_constant () && op2->is_constant ())
+    {
+      octave_value tmp = e->rvalue1 ();
+
+      if (! (error_state || warning_state))
+        {
+          tree_constant *tc_retval
+            = new tree_constant (tmp, op1->line (), op1->column ());
+
+          std::ostringstream buf;
+
+          tree_print_code tpc (buf);
+
+          e->accept (tpc);
+
+          tc_retval->stash_original_text (buf.str ());
+
+          delete e;
+
+          retval = tc_retval;
+        }
+    }
+
+  return retval;
+}
+
+static tree_expression *
+fold (tree_unary_expression *e)
+{
+  tree_expression *retval = e;
+
+  unwind_protect frame;
+
+  frame.protect_var (error_state);
+  frame.protect_var (warning_state);
+
+  frame.protect_var (discard_error_messages);
+  frame.protect_var (discard_warning_messages);
+
+  discard_error_messages = true;
+  discard_warning_messages = true;
+
+  tree_expression *op = e->operand ();
+
+  if (op->is_constant ())
+    {
+      octave_value tmp = e->rvalue1 ();
+
+      if (! (error_state || warning_state))
+        {
+          tree_constant *tc_retval
+            = new tree_constant (tmp, op->line (), op->column ());
+
+          std::ostringstream buf;
+
+          tree_print_code tpc (buf);
+
+          e->accept (tpc);
+
+          tc_retval->stash_original_text (buf.str ());
+
+          delete e;
+
+          retval = tc_retval;
+        }
+    }
+
+  return retval;
+}
+
+// Finish building a range.
+
+tree_expression *
+octave_parser::finish_colon_expression (tree_colon_expression *e)
+{
+  tree_expression *retval = e;
+
+  unwind_protect frame;
+
+  frame.protect_var (error_state);
+  frame.protect_var (warning_state);
+
+  frame.protect_var (discard_error_messages);
+  frame.protect_var (discard_warning_messages);
+
+  discard_error_messages = true;
+  discard_warning_messages = true;
+
+  tree_expression *base = e->base ();
+  tree_expression *limit = e->limit ();
+  tree_expression *incr = e->increment ();
+
+  if (base)
+    {
+      if (limit)
+        {
+          if (base->is_constant () && limit->is_constant ()
+              && (! incr || (incr && incr->is_constant ())))
+            {
+              octave_value tmp = e->rvalue1 ();
+
+              if (! (error_state || warning_state))
+                {
+                  tree_constant *tc_retval
+                    = new tree_constant (tmp, base->line (), base->column ());
+
+                  std::ostringstream buf;
+
+                  tree_print_code tpc (buf);
+
+                  e->accept (tpc);
+
+                  tc_retval->stash_original_text (buf.str ());
+
+                  delete e;
+
+                  retval = tc_retval;
+                }
+            }
+        }
+      else
+        {
+          e->preserve_base ();
+          delete e;
+
+          // FIXME -- need to attempt constant folding here
+          // too (we need a generic way to do that).
+          retval = base;
+        }
+    }
+
+  return retval;
+}
+
+// Make a constant.
+
+tree_constant *
+octave_parser::make_constant (int op, token *tok_val)
+{
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  tree_constant *retval = 0;
+
+  switch (op)
+    {
+    case NUM:
+      {
+        octave_value tmp (tok_val->number ());
+        retval = new tree_constant (tmp, l, c);
+        retval->stash_original_text (tok_val->text_rep ());
+      }
+      break;
+
+    case IMAG_NUM:
+      {
+        octave_value tmp (Complex (0.0, tok_val->number ()));
+        retval = new tree_constant (tmp, l, c);
+        retval->stash_original_text (tok_val->text_rep ());
+      }
+      break;
+
+    case DQ_STRING:
+    case SQ_STRING:
+      {
+        std::string txt = tok_val->text ();
+
+        char delim = op == DQ_STRING ? '"' : '\'';
+        octave_value tmp (txt, delim);
+
+        if (txt.empty ())
+          {
+            if (op == DQ_STRING)
+              tmp = octave_null_str::instance;
+            else
+              tmp = octave_null_sq_str::instance;
+          }
+
+        retval = new tree_constant (tmp, l, c);
+
+        if (op == DQ_STRING)
+          txt = undo_string_escapes (txt);
+
+        // FIXME -- maybe this should also be handled by
+        // tok_val->text_rep () for character strings?
+        retval->stash_original_text (delim + txt + delim);
+      }
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  return retval;
+}
+
+// Make a function handle.
+
+tree_fcn_handle *
+octave_parser::make_fcn_handle (token *tok_val)
+{
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  tree_fcn_handle *retval = new tree_fcn_handle (tok_val->text (), l, c);
+
+  return retval;
+}
+
+// Make an anonymous function handle.
+
+tree_anon_fcn_handle *
+octave_parser::make_anon_fcn_handle (tree_parameter_list *param_list,
+                                     tree_statement *stmt)
+{
+  // FIXME -- need to get these from the location of the @ symbol.
+  int l = curr_lexer->input_line_number;
+  int c = curr_lexer->current_input_column;
+
+  tree_parameter_list *ret_list = 0;
+
+  symbol_table::scope_id fcn_scope = symbol_table::current_scope ();
+
+  if (parser_symtab_context.empty ())
+    panic_impossible ();
+
+  parser_symtab_context.pop ();
+
+  stmt->set_print_flag (false);
+
+  tree_statement_list *body = new tree_statement_list (stmt);
+
+  body->mark_as_anon_function_body ();
+
+  tree_anon_fcn_handle *retval
+    = new tree_anon_fcn_handle (param_list, ret_list, body, fcn_scope, l, c);
+  // FIXME: Stash the filename.  This does not work and produces
+  // errors when executed.
+  //retval->stash_file_name (curr_fcn_file_name);
+
+  return retval;
+}
+
+// Build a binary expression.
+
+tree_expression *
+octave_parser::make_binary_op (int op, tree_expression *op1, token *tok_val,
+                               tree_expression *op2)
+{
+  octave_value::binary_op t = octave_value::unknown_binary_op;
+
+  switch (op)
+    {
+    case POW:
+      t = octave_value::op_pow;
+      break;
+
+    case EPOW:
+      t = octave_value::op_el_pow;
+      break;
+
+    case '+':
+      t = octave_value::op_add;
+      break;
+
+    case '-':
+      t = octave_value::op_sub;
+      break;
+
+    case '*':
+      t = octave_value::op_mul;
+      break;
+
+    case '/':
+      t = octave_value::op_div;
+      break;
+
+    case EMUL:
+      t = octave_value::op_el_mul;
+      break;
+
+    case EDIV:
+      t = octave_value::op_el_div;
+      break;
+
+    case LEFTDIV:
+      t = octave_value::op_ldiv;
+      break;
+
+    case ELEFTDIV:
+      t = octave_value::op_el_ldiv;
+      break;
+
+    case LSHIFT:
+      t = octave_value::op_lshift;
+      break;
+
+    case RSHIFT:
+      t = octave_value::op_rshift;
+      break;
+
+    case EXPR_LT:
+      t = octave_value::op_lt;
+      break;
+
+    case EXPR_LE:
+      t = octave_value::op_le;
+      break;
+
+    case EXPR_EQ:
+      t = octave_value::op_eq;
+      break;
+
+    case EXPR_GE:
+      t = octave_value::op_ge;
+      break;
+
+    case EXPR_GT:
+      t = octave_value::op_gt;
+      break;
+
+    case EXPR_NE:
+      t = octave_value::op_ne;
+      break;
+
+    case EXPR_AND:
+      t = octave_value::op_el_and;
+      break;
+
+    case EXPR_OR:
+      t = octave_value::op_el_or;
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  tree_binary_expression *e
+    = maybe_compound_binary_expression (op1, op2, l, c, t);
+
+  return fold (e);
+}
+
+// Build a boolean expression.
+
+tree_expression *
+octave_parser::make_boolean_op (int op, tree_expression *op1, token *tok_val,
+                                tree_expression *op2)
+{
+  tree_boolean_expression::type t;
+
+  switch (op)
+    {
+    case EXPR_AND_AND:
+      t = tree_boolean_expression::bool_and;
+      break;
+
+    case EXPR_OR_OR:
+      t = tree_boolean_expression::bool_or;
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  tree_boolean_expression *e
+    = new tree_boolean_expression (op1, op2, l, c, t);
+
+  return fold (e);
+}
+
+// Build a prefix expression.
+
+tree_expression *
+octave_parser::make_prefix_op (int op, tree_expression *op1, token *tok_val)
+{
+  octave_value::unary_op t = octave_value::unknown_unary_op;
+
+  switch (op)
+    {
+    case EXPR_NOT:
+      t = octave_value::op_not;
+      break;
+
+    case '+':
+      t = octave_value::op_uplus;
+      break;
+
+    case '-':
+      t = octave_value::op_uminus;
+      break;
+
+    case PLUS_PLUS:
+      t = octave_value::op_incr;
+      break;
+
+    case MINUS_MINUS:
+      t = octave_value::op_decr;
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  tree_prefix_expression *e
+    = new tree_prefix_expression (op1, l, c, t);
+
+  return fold (e);
+}
+
+// Build a postfix expression.
+
+tree_expression *
+octave_parser::make_postfix_op (int op, tree_expression *op1, token *tok_val)
+{
+  octave_value::unary_op t = octave_value::unknown_unary_op;
+
+  switch (op)
+    {
+    case QUOTE:
+      t = octave_value::op_hermitian;
+      break;
+
+    case TRANSPOSE:
+      t = octave_value::op_transpose;
+      break;
+
+    case PLUS_PLUS:
+      t = octave_value::op_incr;
+      break;
+
+    case MINUS_MINUS:
+      t = octave_value::op_decr;
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  tree_postfix_expression *e
+    = new tree_postfix_expression (op1, l, c, t);
+
+  return fold (e);
+}
+
+// Build an unwind-protect command.
+
+tree_command *
+octave_parser::make_unwind_command (token *unwind_tok,
+                                    tree_statement_list *body,
+                                    tree_statement_list *cleanup_stmts,
+                                    token *end_tok,
+                                    octave_comment_list *lc,
+                                    octave_comment_list *mc)
+{
+  tree_command *retval = 0;
+
+  if (end_token_ok (end_tok, token::unwind_protect_end))
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      int l = unwind_tok->line ();
+      int c = unwind_tok->column ();
+
+      retval = new tree_unwind_protect_command (body, cleanup_stmts,
+                                                lc, mc, tc, l, c);
+    }
+
+  return retval;
+}
+
+// Build a try-catch command.
+
+tree_command *
+octave_parser::make_try_command (token *try_tok, tree_statement_list *body,
+                                 tree_statement_list *cleanup_stmts,
+                                 token *end_tok,
+                                 octave_comment_list *lc,
+                                 octave_comment_list *mc)
+{
+  tree_command *retval = 0;
+
+  if (end_token_ok (end_tok, token::try_catch_end))
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      int l = try_tok->line ();
+      int c = try_tok->column ();
+
+      retval = new tree_try_catch_command (body, cleanup_stmts,
+                                           lc, mc, tc, l, c);
+    }
+
+  return retval;
+}
+
+// Build a while command.
+
+tree_command *
+octave_parser::make_while_command (token *while_tok, tree_expression *expr,
+                                   tree_statement_list *body, token *end_tok,
+                                   octave_comment_list *lc)
+{
+  tree_command *retval = 0;
+
+  maybe_warn_assign_as_truth_value (expr);
+
+  if (end_token_ok (end_tok, token::while_end))
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      curr_lexer->looping--;
+
+      int l = while_tok->line ();
+      int c = while_tok->column ();
+
+      retval = new tree_while_command (expr, body, lc, tc, l, c);
+    }
+
+  return retval;
+}
+
+// Build a do-until command.
+
+tree_command *
+octave_parser::make_do_until_command (token *until_tok,
+                                      tree_statement_list *body,
+                                      tree_expression *expr,
+                                      octave_comment_list *lc)
+{
+  tree_command *retval = 0;
+
+  maybe_warn_assign_as_truth_value (expr);
+
+  octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+  curr_lexer->looping--;
+
+  int l = until_tok->line ();
+  int c = until_tok->column ();
+
+  retval = new tree_do_until_command (expr, body, lc, tc, l, c);
+
+  return retval;
+}
+
+// Build a for command.
+
+tree_command *
+octave_parser::make_for_command (int tok_id, token *for_tok,
+                                 tree_argument_list *lhs,
+                                 tree_expression *expr,
+                                 tree_expression *maxproc,
+                                 tree_statement_list *body, token *end_tok,
+                                 octave_comment_list *lc)
+{
+  tree_command *retval = 0;
+
+  bool parfor = tok_id == PARFOR;
+
+  if (end_token_ok (end_tok, parfor ? token::parfor_end : token::for_end))
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      curr_lexer->looping--;
+
+      int l = for_tok->line ();
+      int c = for_tok->column ();
+
+      if (lhs->length () == 1)
+        {
+          tree_expression *tmp = lhs->remove_front ();
+
+          retval = new tree_simple_for_command (parfor, tmp, expr, maxproc,
+                                                body, lc, tc, l, c);
+
+          delete lhs;
+        }
+      else
+        {
+          if (parfor)
+            bison_error ("invalid syntax for parfor statement");
+          else
+            retval = new tree_complex_for_command (lhs, expr, body,
+                                                   lc, tc, l, c);
+        }
+    }
+
+  return retval;
+}
+
+// Build a break command.
+
+tree_command *
+octave_parser::make_break_command (token *break_tok)
+{
+  tree_command *retval = 0;
+
+  int l = break_tok->line ();
+  int c = break_tok->column ();
+
+  retval = new tree_break_command (l, c);
+
+  return retval;
+}
+
+// Build a continue command.
+
+tree_command *
+octave_parser::make_continue_command (token *continue_tok)
+{
+  tree_command *retval = 0;
+
+  int l = continue_tok->line ();
+  int c = continue_tok->column ();
+
+  retval = new tree_continue_command (l, c);
+
+  return retval;
+}
+
+// Build a return command.
+
+tree_command *
+octave_parser::make_return_command (token *return_tok)
+{
+  tree_command *retval = 0;
+
+  int l = return_tok->line ();
+  int c = return_tok->column ();
+
+  retval = new tree_return_command (l, c);
+
+  return retval;
+}
+
+// Start an if command.
+
+tree_if_command_list *
+octave_parser::start_if_command (tree_expression *expr,
+                                 tree_statement_list *list)
+{
+  maybe_warn_assign_as_truth_value (expr);
+
+  tree_if_clause *t = new tree_if_clause (expr, list);
+
+  return new tree_if_command_list (t);
+}
+
+// Finish an if command.
+
+tree_if_command *
+octave_parser::finish_if_command (token *if_tok, tree_if_command_list *list,
+                                  token *end_tok, octave_comment_list *lc)
+{
+  tree_if_command *retval = 0;
+
+  if (end_token_ok (end_tok, token::if_end))
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      int l = if_tok->line ();
+      int c = if_tok->column ();
+
+      if (list && ! list->empty ())
+        {
+          tree_if_clause *elt = list->front ();
+
+          if (elt)
+            {
+              elt->line (l);
+              elt->column (c);
+            }
+        }
+
+      retval = new tree_if_command (list, lc, tc, l, c);
+    }
+
+  return retval;
+}
+
+// Build an elseif clause.
+
+tree_if_clause *
+octave_parser::make_elseif_clause (token *elseif_tok, tree_expression *expr,
+                                   tree_statement_list *list,
+                                   octave_comment_list *lc)
+{
+  maybe_warn_assign_as_truth_value (expr);
+
+  int l = elseif_tok->line ();
+  int c = elseif_tok->column ();
+
+  return new tree_if_clause (expr, list, lc, l, c);
+}
+
+// Finish a switch command.
+
+tree_switch_command *
+octave_parser::finish_switch_command (token *switch_tok, tree_expression *expr,
+                                      tree_switch_case_list *list,
+                                      token *end_tok, octave_comment_list *lc)
+{
+  tree_switch_command *retval = 0;
+
+  if (end_token_ok (end_tok, token::switch_end))
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      int l = switch_tok->line ();
+      int c = switch_tok->column ();
+
+      if (list && ! list->empty ())
+        {
+          tree_switch_case *elt = list->front ();
+
+          if (elt)
+            {
+              elt->line (l);
+              elt->column (c);
+            }
+        }
+
+      retval = new tree_switch_command (expr, list, lc, tc, l, c);
+    }
+
+  return retval;
+}
+
+// Build a switch case.
+
+tree_switch_case *
+octave_parser::make_switch_case (token *case_tok, tree_expression *expr,
+                                 tree_statement_list *list,
+                                 octave_comment_list *lc)
+{
+  maybe_warn_variable_switch_label (expr);
+
+  int l = case_tok->line ();
+  int c = case_tok->column ();
+
+  return new tree_switch_case (expr, list, lc, l, c);
+}
+
+// Build an assignment to a variable.
+
+tree_expression *
+octave_parser::make_assign_op (int op, tree_argument_list *lhs, token *eq_tok,
+                               tree_expression *rhs)
+{
+  tree_expression *retval = 0;
+
+  octave_value::assign_op t = octave_value::unknown_assign_op;
+
+  switch (op)
+    {
+    case '=':
+      t = octave_value::op_asn_eq;
+      break;
+
+    case ADD_EQ:
+      t = octave_value::op_add_eq;
+      break;
+
+    case SUB_EQ:
+      t = octave_value::op_sub_eq;
+      break;
+
+    case MUL_EQ:
+      t = octave_value::op_mul_eq;
+      break;
+
+    case DIV_EQ:
+      t = octave_value::op_div_eq;
+      break;
+
+    case LEFTDIV_EQ:
+      t = octave_value::op_ldiv_eq;
+      break;
+
+    case POW_EQ:
+      t = octave_value::op_pow_eq;
+      break;
+
+    case LSHIFT_EQ:
+      t = octave_value::op_lshift_eq;
+      break;
+
+    case RSHIFT_EQ:
+      t = octave_value::op_rshift_eq;
+      break;
+
+    case EMUL_EQ:
+      t = octave_value::op_el_mul_eq;
+      break;
+
+    case EDIV_EQ:
+      t = octave_value::op_el_div_eq;
+      break;
+
+    case ELEFTDIV_EQ:
+      t = octave_value::op_el_ldiv_eq;
+      break;
+
+    case EPOW_EQ:
+      t = octave_value::op_el_pow_eq;
+      break;
+
+    case AND_EQ:
+      t = octave_value::op_el_and_eq;
+      break;
+
+    case OR_EQ:
+      t = octave_value::op_el_or_eq;
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  int l = eq_tok->line ();
+  int c = eq_tok->column ();
+
+  if (lhs->is_simple_assign_lhs ())
+    {
+      tree_expression *tmp = lhs->remove_front ();
+
+      retval = new tree_simple_assignment (tmp, rhs, false, l, c, t);
+
+      delete lhs;
+    }
+  else if (t == octave_value::op_asn_eq)
+    return new tree_multi_assignment (lhs, rhs, false, l, c);
+  else
+    bison_error ("computed multiple assignment not allowed");
+
+  return retval;
+}
+
+// Define a script.
+
+void
+octave_parser::make_script (tree_statement_list *cmds,
+                            tree_statement *end_script)
+{
+  std::string doc_string;
+
+  if (! help_buf.empty ())
+    {
+      doc_string = help_buf.top ();
+      help_buf.pop ();
+    }
+
+  if (! cmds)
+    cmds = new tree_statement_list ();
+
+  cmds->append (end_script);
+
+  octave_user_script *script
+    = new octave_user_script (curr_fcn_file_full_name, curr_fcn_file_name,
+                              cmds, doc_string);
+
+  octave_time now;
+
+  script->stash_fcn_file_time (now);
+
+  primary_fcn_ptr = script;
+
+  // Unmark any symbols that may have been tagged as local variables
+  // while parsing (for example, by force_local_variable in lex.l).
+
+  symbol_table::unmark_forced_variables ();
+}
+
+// Begin defining a function.
+
+octave_user_function *
+octave_parser::start_function (tree_parameter_list *param_list,
+                               tree_statement_list *body,
+                               tree_statement *end_fcn_stmt)
+{
+  // We'll fill in the return list later.
+
+  if (! body)
+    body = new tree_statement_list ();
+
+  body->append (end_fcn_stmt);
+
+  octave_user_function *fcn
+    = new octave_user_function (symbol_table::current_scope (),
+                                param_list, 0, body);
+
+  if (fcn)
+    {
+      octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+      fcn->stash_trailing_comment (tc);
+    }
+
+  return fcn;
+}
+
+tree_statement *
+octave_parser::make_end (const std::string& type, int l, int c)
+{
+  return make_statement (new tree_no_op_command (type, l, c));
+}
+
+// Do most of the work for defining a function.
+
+octave_user_function *
+octave_parser::frob_function (const std::string& fname,
+                              octave_user_function *fcn)
+{
+  std::string id_name = fname;
+
+  // If input is coming from a file, issue a warning if the name of
+  // the file does not match the name of the function stated in the
+  // file.  Matlab doesn't provide a diagnostic (it ignores the stated
+  // name).
+  if (! autoloading && reading_fcn_file
+      && curr_fcn_depth == 1 && ! parsing_subfunctions)
+  {
+    // FIXME -- should curr_fcn_file_name already be
+    // preprocessed when we get here?  It seems to only be a
+    // problem with relative file names.
+
+    std::string nm = curr_fcn_file_name;
+
+    size_t pos = nm.find_last_of (file_ops::dir_sep_chars ());
+
+    if (pos != std::string::npos)
+      nm = curr_fcn_file_name.substr (pos+1);
+
+    if (nm != id_name)
+      {
+        warning_with_id
+          ("Octave:function-name-clash",
+           "function name '%s' does not agree with function file name '%s'",
+           id_name.c_str (), curr_fcn_file_full_name.c_str ());
+
+        id_name = nm;
+      }
+  }
+
+  if (reading_fcn_file || reading_classdef_file || autoloading)
+    {
+      octave_time now;
+
+      fcn->stash_fcn_file_name (curr_fcn_file_full_name);
+      fcn->stash_fcn_file_time (now);
+      fcn->mark_as_system_fcn_file ();
+
+      if (fcn_file_from_relative_lookup)
+        fcn->mark_relative ();
+
+      if (curr_fcn_depth > 1 || parsing_subfunctions)
+        {
+          fcn->stash_parent_fcn_name (curr_fcn_file_name);
+
+          if (curr_fcn_depth > 1)
+            fcn->stash_parent_fcn_scope (function_scopes[function_scopes.size ()-2]);
+          else
+            fcn->stash_parent_fcn_scope (primary_fcn_scope);
+        }
+
+      if (curr_lexer->parsing_class_method)
+        {
+          if (curr_class_name == id_name)
+            fcn->mark_as_class_constructor ();
+          else
+            fcn->mark_as_class_method ();
+
+          fcn->stash_dispatch_class (curr_class_name);
+        }
+
+      std::string nm = fcn->fcn_file_name ();
+
+      file_stat fs (nm);
+
+      if (fs && fs.is_newer (now))
+        warning_with_id ("Octave:future-time-stamp",
+                         "time stamp for '%s' is in the future", nm.c_str ());
+    }
+  else if (! (input_from_tmp_history_file || input_from_startup_file)
+           && reading_script_file
+           && curr_fcn_file_name == id_name)
+    {
+      warning ("function '%s' defined within script file '%s'",
+               id_name.c_str (), curr_fcn_file_full_name.c_str ());
+    }
+
+  fcn->stash_function_name (id_name);
+  fcn->stash_fcn_location (curr_lexer->input_line_number,
+                           curr_lexer->current_input_column);
+
+  if (! help_buf.empty () && curr_fcn_depth == 1
+      && ! parsing_subfunctions)
+    {
+      fcn->document (help_buf.top ());
+
+      help_buf.pop ();
+    }
+
+  if (reading_fcn_file && curr_fcn_depth == 1
+      && ! parsing_subfunctions)
+    primary_fcn_ptr = fcn;
+
+  return fcn;
+}
+
+tree_function_def *
+octave_parser::finish_function (tree_parameter_list *ret_list,
+                                octave_user_function *fcn,
+                                octave_comment_list *lc)
+{
+  tree_function_def *retval = 0;
+
+  if (ret_list)
+    ret_list->mark_as_formal_parameters ();
+
+  if (fcn)
+    {
+      std::string nm = fcn->name ();
+      std::string file = fcn->fcn_file_name ();
+
+      std::string tmp = nm;
+      if (! file.empty ())
+        tmp += ": " + file;
+
+      symbol_table::cache_name (fcn->scope (), tmp);
+
+      if (lc)
+        fcn->stash_leading_comment (lc);
+
+      fcn->define_ret_list (ret_list);
+
+      if (curr_fcn_depth > 1 || parsing_subfunctions)
+        {
+          fcn->mark_as_subfunction ();
+
+          if (endfunction_found && function_scopes.size () > 1)
+            {
+              symbol_table::scope_id pscope
+                = function_scopes[function_scopes.size ()-2];
+
+              symbol_table::install_nestfunction (nm, octave_value (fcn),
+                                                  pscope);
+            }
+          else
+            symbol_table::install_subfunction (nm, octave_value (fcn),
+                                               primary_fcn_scope);
+        }
+
+      if (curr_fcn_depth == 1 && fcn)
+        symbol_table::update_nest (fcn->scope ());
+
+      if (! reading_fcn_file && curr_fcn_depth == 1)
+        {
+          // We are either reading a script file or defining a function
+          // at the command line, so this definition creates a
+          // tree_function object that is placed in the parse tree.
+          // Otherwise, it is just inserted in the symbol table,
+          // either as a subfunction or nested function (see above),
+          // or as the primary function for the file, via
+          // primary_fcn_ptr (see also load_fcn_from_file,,
+          // parse_fcn_file, and
+          // symbol_table::fcn_info::fcn_info_rep::find_user_function).
+
+          retval = new tree_function_def (fcn);
+        }
+
+      // Unmark any symbols that may have been tagged as local
+      // variables while parsing (for example, by force_local_variable
+      // in lex.l).
+
+      symbol_table::unmark_forced_variables (fcn->scope ());
+    }
+
+  return retval;
+}
+
+void
+octave_parser::recover_from_parsing_function (void)
+{
+  if (parser_symtab_context.empty ())
+    panic_impossible ();
+
+  parser_symtab_context.pop ();
+
+  if (reading_fcn_file && curr_fcn_depth == 1
+      && ! parsing_subfunctions)
+    parsing_subfunctions = true;
+
+  curr_fcn_depth--;
+  function_scopes.pop_back ();
+
+  curr_lexer->defining_func--;
+  curr_lexer->parsed_function_name.pop ();
+  curr_lexer->looking_at_return_list = false;
+  curr_lexer->looking_at_parameter_list = false;
+}
+
+// Make an index expression.
+
+tree_index_expression *
+octave_parser::make_index_expression (tree_expression *expr,
+                                      tree_argument_list *args, char type)
+{
+  tree_index_expression *retval = 0;
+
+  if (args && args->has_magic_tilde ())
+    {
+      bison_error ("invalid use of empty argument (~) in index expression");
+      return retval;
+    }
+
+  int l = expr->line ();
+  int c = expr->column ();
+
+  expr->mark_postfix_indexed ();
+
+  if (expr->is_index_expression ())
+    {
+      tree_index_expression *tmp = static_cast<tree_index_expression *> (expr);
+
+      tmp->append (args, type);
+
+      retval = tmp;
+    }
+  else
+    retval = new tree_index_expression (expr, args, l, c, type);
+
+  return retval;
+}
+
+// Make an indirect reference expression.
+
+tree_index_expression *
+octave_parser::make_indirect_ref (tree_expression *expr,
+                                  const std::string& elt)
+{
+  tree_index_expression *retval = 0;
+
+  int l = expr->line ();
+  int c = expr->column ();
+
+  if (expr->is_index_expression ())
+    {
+      tree_index_expression *tmp = static_cast<tree_index_expression *> (expr);
+
+      tmp->append (elt);
+
+      retval = tmp;
+    }
+  else
+    retval = new tree_index_expression (expr, elt, l, c);
+
+  curr_lexer->looking_at_indirect_ref = false;
+
+  return retval;
+}
+
+// Make an indirect reference expression with dynamic field name.
+
+tree_index_expression *
+octave_parser::make_indirect_ref (tree_expression *expr, tree_expression *elt)
+{
+  tree_index_expression *retval = 0;
+
+  int l = expr->line ();
+  int c = expr->column ();
+
+  if (expr->is_index_expression ())
+    {
+      tree_index_expression *tmp = static_cast<tree_index_expression *> (expr);
+
+      tmp->append (elt);
+
+      retval = tmp;
+    }
+  else
+    retval = new tree_index_expression (expr, elt, l, c);
+
+  curr_lexer->looking_at_indirect_ref = false;
+
+  return retval;
+}
+
+// Make a declaration command.
+
+tree_decl_command *
+octave_parser::make_decl_command (int tok, token *tok_val,
+                                  tree_decl_init_list *lst)
+{
+  tree_decl_command *retval = 0;
+
+  int l = tok_val->line ();
+  int c = tok_val->column ();
+
+  switch (tok)
+    {
+    case GLOBAL:
+      retval = new tree_global_command (lst, l, c);
+      break;
+
+    case PERSISTENT:
+      if (curr_fcn_depth > 0)
+        retval = new tree_persistent_command (lst, l, c);
+      else
+        {
+          if (reading_script_file)
+            warning ("ignoring persistent declaration near line %d of file '%s'",
+                     l, curr_fcn_file_full_name.c_str ());
+          else
+            warning ("ignoring persistent declaration near line %d", l);
+        }
+      break;
+
+    default:
+      panic_impossible ();
+      break;
+    }
+
+  return retval;
+}
+
+tree_argument_list *
+octave_parser::validate_matrix_row (tree_argument_list *row)
+{
+  if (row && row->has_magic_tilde ())
+    bison_error ("invalid use of tilde (~) in matrix expression");
+  return row;
+}
+
+// Finish building a matrix list.
+
+tree_expression *
+octave_parser::finish_matrix (tree_matrix *m)
+{
+  tree_expression *retval = m;
+
+  unwind_protect frame;
+
+  frame.protect_var (error_state);
+  frame.protect_var (warning_state);
+
+  frame.protect_var (discard_error_messages);
+  frame.protect_var (discard_warning_messages);
+
+  discard_error_messages = true;
+  discard_warning_messages = true;
+
+  if (m->all_elements_are_constant ())
+    {
+      octave_value tmp = m->rvalue1 ();
+
+      if (! (error_state || warning_state))
+        {
+          tree_constant *tc_retval
+            = new tree_constant (tmp, m->line (), m->column ());
+
+          std::ostringstream buf;
+
+          tree_print_code tpc (buf);
+
+          m->accept (tpc);
+
+          tc_retval->stash_original_text (buf.str ());
+
+          delete m;
+
+          retval = tc_retval;
+        }
+    }
+
+  return retval;
+}
+
+// Finish building a cell list.
+
+tree_expression *
+octave_parser::finish_cell (tree_cell *c)
+{
+  return finish_matrix (c);
+}
+
+void
+octave_parser::maybe_warn_missing_semi (tree_statement_list *t)
+{
+  if (curr_fcn_depth > 0)
+    {
+      tree_statement *tmp = t->back ();
+
+      if (tmp->is_expression ())
+        warning_with_id
+          ("Octave:missing-semicolon",
+           "missing semicolon near line %d, column %d in file '%s'",
+            tmp->line (), tmp->column (), curr_fcn_file_full_name.c_str ());
+    }
+}
+
+tree_statement_list *
+octave_parser::set_stmt_print_flag (tree_statement_list *list, char sep,
+                                    bool warn_missing_semi)
+{
+  tree_statement *tmp = list->back ();
+
+  switch (sep)
+    {
+    case ';':
+      tmp->set_print_flag (false);
+      break;
+
+    case 0:
+    case ',':
+    case '\n':
+      tmp->set_print_flag (true);
+      if (warn_missing_semi)
+        maybe_warn_missing_semi (list);
+      break;
+
+    default:
+      warning ("unrecognized separator type!");
+      break;
+    }
+
+  // Even if a statement is null, we add it to the list then remove it
+  // here so that the print flag is applied to the correct statement.
+
+  if (tmp->is_null_statement ())
+    {
+      list->pop_back ();
+      delete tmp;
+    }
+
+  return list;
+}
+
+tree_statement_list *
+octave_parser::make_statement_list (tree_statement *stmt)
+{
+  return new tree_statement_list (stmt);
+}
+
+tree_statement_list *
+octave_parser::append_statement_list (tree_statement_list *list, char sep,
+                                      tree_statement *stmt,
+                                      bool warn_missing_semi)
+{
+  set_stmt_print_flag (list, sep, warn_missing_semi);
+
+  list->append (stmt);
+
+  return list;
+}
+
+void
+octave_parser::bison_error (const char *s)
+{
+  int err_col = curr_lexer->current_input_column - 1;
+
+  std::ostringstream output_buf;
+
+  if (reading_fcn_file || reading_script_file || reading_classdef_file)
+    output_buf << "parse error near line " << curr_lexer->input_line_number
+               << " of file " << curr_fcn_file_full_name;
+  else
+    output_buf << "parse error:";
+
+  if (s && strcmp (s, "parse error") != 0)
+    output_buf << "\n\n  " << s;
+
+  output_buf << "\n\n";
+
+  if (! current_input_line.empty ())
+    {
+      size_t len = current_input_line.length ();
+
+      if (current_input_line[len-1] == '\n')
+        current_input_line.resize (len-1);
+
+      // Print the line, maybe with a pointer near the error token.
+
+      output_buf << ">>> " << current_input_line << "\n";
+
+      if (err_col == 0)
+        err_col = len;
+
+      for (int i = 0; i < err_col + 3; i++)
+        output_buf << " ";
+
+      output_buf << "^";
+    }
+
+  output_buf << "\n";
+
+  std::string msg = output_buf.str ();
+
+  parse_error ("%s", msg.c_str ());
+}
+
+static void
+safe_fclose (FILE *f)
+{
+  // FIXME -- comments at the end of an input file are
+  // discarded (otherwise, they would be appended to the next
+  // statement, possibly from the command line or another file, which
+  // can be quite confusing).
+
+  octave_comment_list *tc = octave_comment_buffer::get_comment ();
+
+  delete tc;
+
+  if (f)
+    fclose (static_cast<FILE *> (f));
+}
+
+static bool
+looks_like_copyright (const std::string& s)
+{
+  bool retval = false;
+
+  if (! s.empty ())
+    {
+      size_t offset = s.find_first_not_of (" \t");
+
+      retval = (s.substr (offset, 9) == "Copyright" || s.substr (offset, 6) == "Author");
+    }
+
+  return retval;
+}
+
+static int
+text_getc (FILE *f)
+{
+  int c = gnulib::getc (f);
+
+  // Convert CRLF into just LF and single CR into LF.
+
+  if (c == '\r')
+    {
+      c = gnulib::getc (f);
+
+      if (c != '\n')
+        {
+          ungetc (c, f);
+          c = '\n';
+        }
+    }
+
+  return c;
+}
+
+class
+stdio_stream_reader : public stream_reader
+{
+public:
+
+  stdio_stream_reader (FILE *f_arg, int& l, int& c)
+    : stream_reader (), f (f_arg), line_num (l), column_num (c)
+  { }
+
+  int getc (void)
+  {
+    char c = ::text_getc (f);
+
+    if (c == '\n')
+      {
+        line_num++;
+        column_num = 0;
+      }
+    else
+      {
+        // FIXME -- try to be smarter about tabs?
+        column_num++;
+      }
+        
+    return c;
+  }
+
+  int ungetc (int c)
+  {
+    if (c == '\n')
+      {   
+        line_num--;
+        column_num = 0;
+      }
+    else
+      {
+        // FIXME -- try to be smarter about tabs?
+        column_num--;
+      }
+
+    return ::ungetc (c, f);
+  }
+
+private:
+
+  FILE *f;
+
+  int& line_num;
+
+  int& column_num;
+
+  // No copying!
+
+  stdio_stream_reader (const  stdio_stream_reader&);
+
+  stdio_stream_reader & operator = (const  stdio_stream_reader&);
+};
+
+static bool
+skip_white_space (stream_reader& reader)
+{
+  int c = 0;
+
+  while ((c = reader.getc ()) != EOF)
+    {
+      switch (c)
+        {
+        case ' ':
+        case '\t':
+        case '\n':
+          break;
+
+        default:
+          reader.ungetc (c);
+          goto done;
+        }
+    }
+
+ done:
+
+  return (c == EOF);
+}
+
+static bool
+looking_at_classdef_keyword (FILE *ffile)
+{
+  bool status = false;
+
+  long pos = gnulib::ftell (ffile);
+
+  char buf [10];
+  gnulib::fgets (buf, 10, ffile);
+  size_t len = strlen (buf);
+  if (len > 8 && strncmp (buf, "classdef", 8) == 0
+      && ! (isalnum (buf[8]) || buf[8] == '_'))
+    status = true;
+
+  gnulib::fseek (ffile, pos, SEEK_SET);
+
+  return status;
+ }
+
+static std::string
+gobble_leading_white_space (FILE *ffile, bool& eof, int& line_num,
+                            int& column_num)
+{
+  std::string help_txt;
+
+  eof = false;
+
+  // TRUE means we have already cached the help text.
+  bool have_help_text = false;
+
+  std::string txt;
+
+  stdio_stream_reader stdio_reader (ffile, line_num, column_num);
+
+  while (true)
+    {
+      eof = skip_white_space (stdio_reader);
+
+      if (eof)
+        break;
+
+      txt = CURR_LEXER->grab_comment_block (stdio_reader, true, eof);
+
+      if (txt.empty ())
+        break;
+
+      if (! (have_help_text || looks_like_copyright (txt)))
+        {
+          help_txt = txt;
+          have_help_text = true;
+        }
+
+      octave_comment_buffer::append (txt);
+
+      if (eof)
+        break;
+    }
+
+  return help_txt;
+}
+
+static std::string
+gobble_leading_white_space (FILE *ffile, bool& eof)
+{
+  int line_num = 1;
+  int column_num = 1;
+
+  return gobble_leading_white_space (ffile, eof, line_num, column_num);
+}
+
+static bool
+looking_at_function_keyword (FILE *ffile)
+{
+  bool status = false;
+
+  long pos = gnulib::ftell (ffile);
+
+  char buf [10];
+  gnulib::fgets (buf, 10, ffile);
+  size_t len = strlen (buf);
+  if (len > 8 && strncmp (buf, "function", 8) == 0
+      && ! (isalnum (buf[8]) || buf[8] == '_'))
+    status = true;
+
+  gnulib::fseek (ffile, pos, SEEK_SET);
+
+  return status;
+}
+
+static octave_function *
+parse_fcn_file (const std::string& ff, const std::string& dispatch_type,
+                bool require_file, bool force_script, bool autoload,    
+                bool relative_lookup, const std::string& warn_for)
+{
+  unwind_protect frame;
+
+  octave_function *fcn_ptr = 0;
+
+  // Open function file and parse.
+
+  FILE *in_stream = command_editor::get_input_stream ();
+
+  frame.add_fcn (command_editor::set_input_stream, in_stream);
+
+  frame.protect_var (ff_instream);
+
+  frame.protect_var (reading_fcn_file);
+  frame.protect_var (line_editing);
+
+  reading_fcn_file = true;
+  line_editing = false;
+
+  frame.add_fcn (command_history::ignore_entries,
+                 command_history::ignoring_entries ());
+
+  command_history::ignore_entries ();
+
+  FILE *ffile = get_input_from_file (ff, 0);
+
+  frame.add_fcn (safe_fclose, ffile);
+
+  if (ffile)
+    {
+      bool eof;
+
+      // octave_parser constructor sets this for us.
+      frame.protect_var (CURR_LEXER);
+
+      octave_parser *curr_parser = new octave_parser ();
+      frame.add_fcn (octave_parser::cleanup, curr_parser);
+
+      curr_parser->curr_class_name = dispatch_type;
+      curr_parser->autoloading = autoload;
+      curr_parser->fcn_file_from_relative_lookup = relative_lookup;
+
+      std::string help_txt
+        = gobble_leading_white_space
+            (ffile, eof,
+             curr_parser->curr_lexer->input_line_number,
+             curr_parser->curr_lexer->current_input_column);
+
+      if (! help_txt.empty ())
+        help_buf.push (help_txt);
+
+      if (! eof)
+        {
+          std::string file_type;
+
+          frame.protect_var (get_input_from_eval_string);
+          frame.protect_var (reading_fcn_file);
+          frame.protect_var (reading_script_file);
+          frame.protect_var (reading_classdef_file);
+          frame.protect_var (Vecho_executing_commands);
+
+          get_input_from_eval_string = false;
+
+          if (! force_script && looking_at_function_keyword (ffile))
+            {
+              file_type = "function";
+
+              Vecho_executing_commands = ECHO_OFF;
+
+              reading_classdef_file = false;
+              reading_fcn_file = true;
+              reading_script_file = false;
+            }
+          else if (! force_script && looking_at_classdef_keyword (ffile))
+            {
+              file_type = "classdef";
+
+              Vecho_executing_commands = ECHO_OFF;
+
+              reading_classdef_file = true;
+              reading_fcn_file = false;
+              // FIXME -- Should classdef files be handled as
+              // scripts or separately?  Currently, without setting up
+              // for reading script files, parsing classdef files
+              // fails.
+              reading_script_file = true;
+            }
+          else
+            {
+              file_type = "script";
+
+              Vecho_executing_commands = ECHO_OFF;
+
+              reading_classdef_file = false;
+              reading_fcn_file = false;
+              reading_script_file = true;
+            }
+
+          // Do this with an unwind-protect cleanup function so that
+          // the forced variables will be unmarked in the event of an
+          // interrupt.
+          symbol_table::scope_id scope = symbol_table::top_scope ();
+          frame.add_fcn (symbol_table::unmark_forced_variables, scope);
+
+          if (! help_txt.empty ())
+            help_buf.push (help_txt);
+
+          if (reading_script_file)
+            curr_parser->curr_lexer->prep_for_script_file ();
+          else
+            curr_parser->curr_lexer->prep_for_function_file ();
+
+          curr_parser->curr_lexer->parsing_class_method = ! dispatch_type.empty ();
+
+          frame.protect_var (global_command);
+
+          global_command = 0;
+
+          int status = curr_parser->run ();
+
+          // Use an unwind-protect cleanup function so that the
+          // global_command list will be deleted in the event of an
+          // interrupt.
+
+          frame.add_fcn (cleanup_statement_list, &global_command);
+
+          fcn_ptr = curr_parser->primary_fcn_ptr;
+
+          if (status != 0)
+            error ("parse error while reading %s file %s",
+                   file_type.c_str (), ff.c_str ());
+        }
+      else
+        {
+          int l = curr_parser->curr_lexer->input_line_number;
+          int c = curr_parser->curr_lexer->current_input_column;
+
+          tree_statement *end_of_script
+            = curr_parser->make_end ("endscript", l, c);
+
+          curr_parser->make_script (0, end_of_script);
+
+          fcn_ptr = curr_parser->primary_fcn_ptr;
+        }
+    }
+  else if (require_file)
+    error ("no such file, '%s'", ff.c_str ());
+  else if (! warn_for.empty ())
+    error ("%s: unable to open file '%s'", warn_for.c_str (), ff.c_str ());
+
+  return fcn_ptr;
+}
+
+std::string
+get_help_from_file (const std::string& nm, bool& symbol_found,
+                    std::string& file)
+{
+  std::string retval;
+
+  file = fcn_file_in_path (nm);
+
+  if (! file.empty ())
+    {
+      symbol_found = true;
+
+      FILE *fptr = gnulib::fopen (file.c_str (), "r");
+
+      if (fptr)
+        {
+          unwind_protect frame;
+          frame.add_fcn (safe_fclose, fptr);
+
+          bool eof;
+          retval = gobble_leading_white_space (fptr, eof);
+
+          if (retval.empty ())
+            {
+              octave_function *fcn = parse_fcn_file (file, "", true,
+                                                     false, false,
+                                                     false, "");
+
+              if (fcn)
+                {
+                  retval = fcn->doc_string ();
+
+                  delete fcn;
+                }
+            }
+        }
+    }
+
+  return retval;
+}
+
+std::string
+get_help_from_file (const std::string& nm, bool& symbol_found)
+{
+  std::string file;
+  return get_help_from_file (nm, symbol_found, file);
+}
+
+std::string
+lookup_autoload (const std::string& nm)
+{
+  std::string retval;
+
+  typedef std::map<std::string, std::string>::const_iterator am_iter;
+
+  am_iter p = autoload_map.find (nm);
+
+  if (p != autoload_map.end ())
+    retval = load_path::find_file (p->second);
+
+  return retval;
+}
+
+string_vector
+autoloaded_functions (void)
+{
+  string_vector names (autoload_map.size ());
+
+  octave_idx_type i = 0;
+  typedef std::map<std::string, std::string>::const_iterator am_iter;
+  for (am_iter p = autoload_map.begin (); p != autoload_map.end (); p++)
+    names[i++] = p->first;
+
+  return names;
+}
+
+string_vector
+reverse_lookup_autoload (const std::string& nm)
+{
+  string_vector names;
+
+  typedef std::map<std::string, std::string>::const_iterator am_iter;
+  for (am_iter p = autoload_map.begin (); p != autoload_map.end (); p++)
+    if (nm == p->second)
+      names.append (p->first);
+
+  return names;
+}
+
+octave_function *
+load_fcn_from_file (const std::string& file_name, const std::string& dir_name,
+                    const std::string& dispatch_type,
+                    const std::string& fcn_name, bool autoload)
+{
+  octave_function *retval = 0;
+
+  unwind_protect frame;
+
+  std::string nm = file_name;
+
+  size_t nm_len = nm.length ();
+
+  std::string file;
+
+  bool relative_lookup = false;
+
+  file = nm;
+
+  if ((nm_len > 4 && nm.substr (nm_len-4) == ".oct")
+      || (nm_len > 4 && nm.substr (nm_len-4) == ".mex")
+      || (nm_len > 2 && nm.substr (nm_len-2) == ".m"))
+    {
+      nm = octave_env::base_pathname (file);
+      nm = nm.substr (0, nm.find_last_of ('.'));
+
+      size_t pos = nm.find_last_of (file_ops::dir_sep_str ());
+      if (pos != std::string::npos)
+        nm = nm.substr (pos+1);
+    }
+
+  relative_lookup = ! octave_env::absolute_pathname (file);
+
+  file = octave_env::make_absolute (file);
+
+  int len = file.length ();
+
+  if (len > 4 && file.substr (len-4, len-1) == ".oct")
+    {
+      if (autoload && ! fcn_name.empty ())
+        nm = fcn_name;
+
+      retval = octave_dynamic_loader::load_oct (nm, file, relative_lookup);
+    }
+  else if (len > 4 && file.substr (len-4, len-1) == ".mex")
+    {
+      // Temporarily load m-file version of mex-file, if it exists,
+      // to get the help-string to use.
+      frame.protect_var (curr_fcn_file_name);
+      frame.protect_var (curr_fcn_file_full_name);
+
+      curr_fcn_file_name = nm;
+      curr_fcn_file_full_name = file.substr (0, len - 2);
+
+      octave_function *tmpfcn = parse_fcn_file (file.substr (0, len - 2),
+                                                dispatch_type, false,
+                                                autoload, autoload,
+                                                relative_lookup, "");
+
+      retval = octave_dynamic_loader::load_mex (nm, file, relative_lookup);
+
+      if (tmpfcn)
+        retval->document (tmpfcn->doc_string ());
+      delete tmpfcn;
+    }
+  else if (len > 2)
+    {
+      // These are needed by yyparse.
+
+      frame.protect_var (curr_fcn_file_name);
+      frame.protect_var (curr_fcn_file_full_name);
+
+      curr_fcn_file_name = nm;
+      curr_fcn_file_full_name = file;
+
+      retval = parse_fcn_file (file, dispatch_type, true, autoload,
+                               autoload, relative_lookup, "");
+    }
+
+  if (retval)
+    {
+      retval->stash_dir_name (dir_name);
+
+      if (retval->is_user_function ())
+        {
+          symbol_table::scope_id id = retval->scope ();
+
+          symbol_table::stash_dir_name_for_subfunctions (id, dir_name);
+        }
+    }
+
+  return retval;
+}
+
+DEFUN (autoload, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} autoload (@var{function}, @var{file})\n\
+Define @var{function} to autoload from @var{file}.\n\
+\n\
+The second argument, @var{file}, should be an absolute file name or\n\
+a file name in the same directory as the function or script from which\n\
+the autoload command was run.  @var{file} should not depend on the\n\
+Octave load path.\n\
+\n\
+Normally, calls to @code{autoload} appear in PKG_ADD script files that\n\
+are evaluated when a directory is added to the Octave's load path.  To\n\
+avoid having to hardcode directory names in @var{file}, if @var{file}\n\
+is in the same directory as the PKG_ADD script then\n\
+\n\
+@example\n\
+autoload (\"foo\", \"bar.oct\");\n\
+@end example\n\
+\n\
+@noindent\n\
+will load the function @code{foo} from the file @code{bar.oct}.  The above\n\
+when @code{bar.oct} is not in the same directory or uses like\n\
+\n\
+@example\n\
+autoload (\"foo\", file_in_loadpath (\"bar.oct\"))\n\
+@end example\n\
+\n\
+@noindent\n\
+are strongly discouraged, as their behavior might be unpredictable.\n\
+\n\
+With no arguments, return a structure containing the current autoload map.\n\
+@seealso{PKG_ADD}\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  int nargin = args.length ();
+
+  if (nargin == 0)
+    {
+      Cell func_names (dim_vector (autoload_map.size (), 1));
+      Cell file_names (dim_vector (autoload_map.size (), 1));
+
+      octave_idx_type i = 0;
+      typedef std::map<std::string, std::string>::const_iterator am_iter;
+      for (am_iter p = autoload_map.begin (); p != autoload_map.end (); p++)
+        {
+          func_names(i) = p->first;
+          file_names(i) = p->second;
+
+          i++;
+        }
+
+      octave_map m;
+
+      m.assign ("function", func_names);
+      m.assign ("file", file_names);
+
+      retval = m;
+    }
+  else if (nargin == 2)
+    {
+      string_vector argv = args.make_argv ("autoload");
+
+      if (! error_state)
+        {
+          std::string nm = argv[2];
+
+          if (! octave_env::absolute_pathname (nm))
+            {
+              octave_user_code *fcn = octave_call_stack::caller_user_code ();
+
+              bool found = false;
+
+              if (fcn)
+                {
+                  std::string fname = fcn->fcn_file_name ();
+
+                  if (! fname.empty ())
+                    {
+                      fname = octave_env::make_absolute (fname);
+                      fname = fname.substr (0, fname.find_last_of (file_ops::dir_sep_str ()) + 1);
+
+                      file_stat fs (fname + nm);
+
+                      if (fs.exists ())
+                        {
+                          nm = fname + nm;
+                          found = true;
+                        }
+                    }
+                }
+              if (! found)
+                warning_with_id ("Octave:autoload-relative-file-name",
+                                 "autoload: '%s' is not an absolute file name",
+                                 nm.c_str ());
+            }
+          autoload_map[argv[1]] = nm;
+        }
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+void
+source_file (const std::string& file_name, const std::string& context,
+             bool verbose, bool require_file, const std::string& warn_for)
+{
+  // Map from absolute name of script file to recursion level.  We
+  // use a map instead of simply placing a limit on recursion in the
+  // source_file function so that two mutually recursive scripts
+  // written as
+  //
+  //   foo1.m:
+  //   ------
+  //   foo2
+  //
+  //   foo2.m:
+  //   ------
+  //   foo1
+  //
+  // and called with
+  //
+  //   foo1
+  //
+  // (for example) will behave the same if they are written as
+  //
+  //   foo1.m:
+  //   ------
+  //   source ("foo2.m")
+  //
+  //   foo2.m:
+  //   ------
+  //   source ("foo1.m")
+  //
+  // and called with
+  //
+  //   source ("foo1.m")
+  //
+  // (for example).
+
+  static std::map<std::string, int> source_call_depth;
+
+  std::string file_full_name = file_ops::tilde_expand (file_name);
+
+  file_full_name = octave_env::make_absolute (file_full_name);
+
+  unwind_protect frame;
+
+  frame.protect_var (curr_fcn_file_name);
+  frame.protect_var (curr_fcn_file_full_name);
+
+  curr_fcn_file_name = file_name;
+  curr_fcn_file_full_name = file_full_name;
+
+  if (source_call_depth.find (file_full_name) == source_call_depth.end ())
+    source_call_depth[file_full_name] = -1;
+
+  frame.protect_var (source_call_depth[file_full_name]);
+
+  source_call_depth[file_full_name]++;
+
+  if (source_call_depth[file_full_name] >= Vmax_recursion_depth)
+    {
+      error ("max_recursion_depth exceeded");
+      return;
+    }
+
+  if (! context.empty ())
+    {
+      if (context == "caller")
+        octave_call_stack::goto_caller_frame ();
+      else if (context == "base")
+        octave_call_stack::goto_base_frame ();
+      else
+        error ("source: context must be \"caller\" or \"base\"");
+
+      if (! error_state)
+        frame.add_fcn (octave_call_stack::pop);
+    }
+
+  if (! error_state)
+    {
+      octave_function *fcn = parse_fcn_file (file_full_name, "",
+                                             require_file, true, false,
+                                             false, warn_for);
+
+      if (! error_state)
+        {
+          if (fcn && fcn->is_user_script ())
+            {
+              octave_value_list args;
+
+              if (verbose)
+                {
+                  std::cout << "executing commands from " << file_full_name << " ... ";
+                  reading_startup_message_printed = true;
+                  std::cout.flush ();
+                }
+
+              fcn->do_multi_index_op (0, args);
+
+              if (verbose)
+                std::cout << "done." << std::endl;
+
+              delete fcn;
+            }
+        }
+      else
+        error ("source: error sourcing file '%s'",
+               file_full_name.c_str ());
+    }
+}
+
+DEFUN (mfilename, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn  {Built-in Function} {} mfilename ()\n\
+@deftypefnx {Built-in Function} {} mfilename (\"fullpath\")\n\
+@deftypefnx {Built-in Function} {} mfilename (\"fullpathext\")\n\
+Return the name of the currently executing file.  At the top-level,\n\
+return the empty string.  Given the argument @code{\"fullpath\"},\n\
+include the directory part of the file name, but not the extension.\n\
+Given the argument @code{\"fullpathext\"}, include the directory part\n\
+of the file name and the extension.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  int nargin = args.length ();
+
+  if (nargin > 1)
+    {
+      print_usage ();
+      return retval;
+    }
+
+  std::string arg;
+
+  if (nargin == 1)
+    {
+      arg = args(0).string_value ();
+
+      if (error_state)
+        {
+          error ("mfilename: expecting argument to be a character string");
+          return retval;
+        }
+    }
+
+  std::string fname;
+
+  octave_user_code *fcn = octave_call_stack::caller_user_code ();
+
+  if (fcn)
+    {
+      fname = fcn->fcn_file_name ();
+
+      if (fname.empty ())
+        fname = fcn->name ();
+    }
+
+  if (arg == "fullpathext")
+    retval = fname;
+  else
+    {
+      size_t dpos = fname.rfind (file_ops::dir_sep_char ());
+      size_t epos = fname.rfind ('.');
+
+      if (epos <= dpos)
+        epos = std::string::npos;
+
+      fname = (epos != std::string::npos) ? fname.substr (0, epos) : fname;
+
+      if (arg == "fullpath")
+        retval = fname;
+      else
+        retval = (dpos != std::string::npos) ? fname.substr (dpos+1) : fname;
+    }
+
+  return retval;
+}
+
+
+DEFUN (source, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} source (@var{file})\n\
+Parse and execute the contents of @var{file}.  This is equivalent to\n\
+executing commands from a script file, but without requiring the file to\n\
+be named @file{@var{file}.m}.\n\
+@end deftypefn")
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin == 1 || nargin == 2)
+    {
+      std::string file_name = args(0).string_value ();
+
+      if (! error_state)
+        {
+          std::string context;
+
+          if (nargin == 2)
+            context = args(1).string_value ();
+
+          if (! error_state)
+            source_file (file_name, context);
+          else
+            error ("source: expecting context to be character string");
+        }
+      else
+        error ("source: expecting file name as argument");
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+// Evaluate an Octave function (built-in or interpreted) and return
+// the list of result values.  NAME is the name of the function to
+// call.  ARGS are the arguments to the function.  NARGOUT is the
+// number of output arguments expected.
+
+octave_value_list
+feval (const std::string& name, const octave_value_list& args, int nargout)
+{
+  octave_value_list retval;
+
+  octave_value fcn = symbol_table::find_function (name, args);
+
+  if (fcn.is_defined ())
+    retval = fcn.do_multi_index_op (nargout, args);
+  else
+    {
+      maybe_missing_function_hook (name);
+      if (! error_state)
+        error ("feval: function '%s' not found", name.c_str ());
+    }
+
+  return retval;
+}
+
+octave_value_list
+feval (octave_function *fcn, const octave_value_list& args, int nargout)
+{
+  octave_value_list retval;
+
+  if (fcn)
+    retval = fcn->do_multi_index_op (nargout, args);
+
+  return retval;
+}
+
+static octave_value_list
+get_feval_args (const octave_value_list& args)
+{
+  return args.slice (1, args.length () - 1, true);
+}
+
+
+// Evaluate an Octave function (built-in or interpreted) and return
+// the list of result values.  The first element of ARGS should be a
+// string containing the name of the function to call, then the rest
+// are the actual arguments to the function.  NARGOUT is the number of
+// output arguments expected.
+
+octave_value_list
+feval (const octave_value_list& args, int nargout)
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin > 0)
+    {
+      octave_value f_arg = args(0);
+
+      if (f_arg.is_string ())
+        {
+          std::string name = f_arg.string_value ();
+
+          if (! error_state)
+            {
+              octave_value_list tmp_args = get_feval_args (args);
+
+              retval = feval (name, tmp_args, nargout);
+            }
+        }
+      else if (f_arg.is_function_handle ()
+               || f_arg.is_anonymous_function ()
+               || f_arg.is_inline_function ())
+        {
+          const octave_value_list tmp_args = get_feval_args (args);
+
+          retval = f_arg.do_multi_index_op (nargout, tmp_args);
+        }
+      else
+        error ("feval: first argument must be a string, inline function or a function handle");
+    }
+
+  return retval;
+}
+
+DEFUN (feval, args, nargout,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} feval (@var{name}, @dots{})\n\
+Evaluate the function named @var{name}.  Any arguments after the first\n\
+are passed on to the named function.  For example,\n\
+\n\
+@example\n\
+@group\n\
+feval (\"acos\", -1)\n\
+     @result{} 3.1416\n\
+@end group\n\
+@end example\n\
+\n\
+@noindent\n\
+calls the function @code{acos} with the argument @samp{-1}.\n\
+\n\
+The function @code{feval} can also be used with function handles of\n\
+any sort (@pxref{Function Handles}).  Historically, @code{feval} was\n\
+the only way to call user-supplied functions in strings, but\n\
+function handles are now preferred due to the cleaner syntax they\n\
+offer.  For example,\n\
+\n\
+@example\n\
+@group\n\
+@var{f} = @@exp;\n\
+feval (@var{f}, 1)\n\
+    @result{} 2.7183\n\
+@var{f} (1)\n\
+    @result{} 2.7183\n\
+@end group\n\
+@end example\n\
+\n\
+@noindent\n\
+are equivalent ways to call the function referred to by @var{f}.  If it\n\
+cannot be predicted beforehand that @var{f} is a function handle or the\n\
+function name in a string, @code{feval} can be used instead.\n\
+@end deftypefn")
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin > 0)
+    retval = feval (args, nargout);
+  else
+    print_usage ();
+
+  return retval;
+}
+
+DEFUN (builtin, args, nargout,
+  "-*- texinfo -*-\n\
+@deftypefn {Loadable Function} {[@dots{}]} builtin (@var{f}, @dots{})\n\
+Call the base function @var{f} even if @var{f} is overloaded to\n\
+another function for the given type signature.\n\
+@end deftypefn")
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin > 0)
+    {
+      const std::string name (args(0).string_value ());
+
+      if (! error_state)
+        {
+          octave_value fcn = symbol_table::builtin_find (name);
+
+          if (fcn.is_defined ())
+            retval = feval (fcn.function_value (), args.splice (0, 1),
+                            nargout);
+          else
+            error ("builtin: lookup for symbol '%s' failed", name.c_str ());
+        }
+      else
+        error ("builtin: function name (F) must be a string");
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+octave_value_list
+eval_string (const std::string& s, bool silent, int& parse_status, int nargout)
+{
+  octave_value_list retval;
+
+  unwind_protect frame;
+
+  // octave_parser constructor sets this for us.
+  frame.protect_var (CURR_LEXER);
+
+  octave_parser *curr_parser = new octave_parser ();
+  frame.add_fcn (octave_parser::cleanup, curr_parser);
+
+  frame.protect_var (get_input_from_eval_string);
+  frame.protect_var (line_editing);
+  frame.protect_var (current_eval_string);
+  frame.protect_var (reading_fcn_file);
+  frame.protect_var (reading_script_file);
+  frame.protect_var (reading_classdef_file);
+
+  get_input_from_eval_string = true;
+  line_editing = false;
+  reading_fcn_file = false;
+  reading_script_file = false;
+  reading_classdef_file = false;
+
+  current_eval_string = s;
+
+  do
+    {
+      curr_parser->reset ();
+
+      frame.protect_var (global_command);
+
+      global_command = 0;
+
+      // Do this with an unwind-protect cleanup function so that the
+      // forced variables will be unmarked in the event of an
+      // interrupt.
+      symbol_table::scope_id scope = symbol_table::top_scope ();
+      frame.add_fcn (symbol_table::unmark_forced_variables, scope);
+
+      parse_status = curr_parser->run ();
+
+      tree_statement_list *command_list = global_command;
+
+      // Unmark forced variables.
+      // Restore previous value of global_command.
+      frame.run (2);
+
+      if (parse_status == 0)
+        {
+          if (command_list)
+            {
+              unwind_protect inner_frame;
+
+              // Use an unwind-protect cleanup function so that the
+              // global_command list will be deleted in the event of an
+              // interrupt.
+
+              inner_frame.add_fcn (cleanup_statement_list, &command_list);
+
+              tree_statement *stmt = 0;
+
+              if (command_list->length () == 1
+                  && (stmt = command_list->front ())
+                  && stmt->is_expression ())
+                {
+                  tree_expression *expr = stmt->expression ();
+
+                  if (silent)
+                    expr->set_print_flag (false);
+
+                  bool do_bind_ans = false;
+
+                  if (expr->is_identifier ())
+                    {
+                      tree_identifier *id
+                        = dynamic_cast<tree_identifier *> (expr);
+
+                      do_bind_ans = (! id->is_variable ());
+                    }
+                  else
+                    do_bind_ans = (! expr->is_assignment_expression ());
+
+                  retval = expr->rvalue (nargout);
+
+                  if (do_bind_ans && ! (error_state || retval.empty ()))
+                    bind_ans (retval(0), expr->print_result ());
+
+                  if (nargout == 0)
+                    retval = octave_value_list ();
+                }
+              else if (nargout == 0)
+                command_list->accept (*current_evaluator);
+              else
+                error ("eval: invalid use of statement list");
+
+              if (error_state
+                  || tree_return_command::returning
+                  || tree_break_command::breaking
+                  || tree_continue_command::continuing)
+                break;
+            }
+          else if (curr_parser->curr_lexer->end_of_input)
+            break;
+        }
+    }
+  while (parse_status == 0);
+
+  return retval;
+}
+
+octave_value
+eval_string (const std::string& s, bool silent, int& parse_status)
+{
+  octave_value retval;
+
+  octave_value_list tmp = eval_string (s, silent, parse_status, 1);
+
+  if (! tmp.empty ())
+    retval = tmp(0);
+
+  return retval;
+}
+
+static octave_value_list
+eval_string (const octave_value& arg, bool silent, int& parse_status,
+             int nargout)
+{
+  std::string s = arg.string_value ();
+
+  if (error_state)
+    {
+      error ("eval: expecting std::string argument");
+      return octave_value (-1);
+    }
+
+  return eval_string (s, silent, parse_status, nargout);
+}
+
+void
+cleanup_statement_list (tree_statement_list **lst)
+{
+  if (*lst)
+    {
+      delete *lst;
+      *lst = 0;
+    }
+}
+
+DEFUN (eval, args, nargout,
+  "-*- texinfo -*-\n\
+@deftypefn  {Built-in Function} {} eval (@var{try})\n\
+@deftypefnx {Built-in Function} {} eval (@var{try}, @var{catch})\n\
+Parse the string @var{try} and evaluate it as if it were an Octave\n\
+program.  If that fails, evaluate the optional string @var{catch}.\n\
+The string @var{try} is evaluated in the current context,\n\
+so any results remain available after @code{eval} returns.\n\
+\n\
+The following example makes the variable @var{a} with the approximate\n\
+value 3.1416 available.\n\
+\n\
+@example\n\
+eval (\"a = acos(-1);\");\n\
+@end example\n\
+\n\
+If an error occurs during the evaluation of @var{try} the @var{catch}\n\
+string is evaluated, as the following example shows:\n\
+\n\
+@example\n\
+@group\n\
+eval ('error (\"This is a bad example\");',\n\
+      'printf (\"This error occurred:\\n%s\\n\", lasterr ());');\n\
+     @print{} This error occurred:\n\
+        This is a bad example\n\
+@end group\n\
+@end example\n\
+\n\
+Consider using try/catch blocks instead if you are only using @code{eval}\n\
+as an error-capturing mechanism rather than for the execution of arbitrary\n\
+code strings.\n\
+@seealso{evalin}\n\
+@end deftypefn")
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin > 0)
+    {
+      unwind_protect frame;
+
+      if (nargin > 1)
+        {
+          frame.protect_var (buffer_error_messages);
+          buffer_error_messages++;
+        }
+
+      int parse_status = 0;
+
+      octave_value_list tmp = eval_string (args(0), nargout > 0,
+                                           parse_status, nargout);
+
+      if (nargin > 1 && (parse_status != 0 || error_state))
+        {
+          error_state = 0;
+
+          // Set up for letting the user print any messages from
+          // errors that occurred in the first part of this eval().
+
+          buffer_error_messages--;
+
+          tmp = eval_string (args(1), nargout > 0, parse_status, nargout);
+
+          if (nargout > 0)
+            retval = tmp;
+        }
+      else if (nargout > 0)
+        retval = tmp;
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+/*
+
+%!shared x
+%! x = 1;
+
+%!assert (eval ("x"), 1)
+%!assert (eval ("x;"))
+%!assert (eval ("x;"), 1);
+
+%!test
+%! y = eval ("x");
+%! assert (y, 1);
+
+%!test
+%! y = eval ("x;");
+%! assert (y, 1);
+
+%!test
+%! eval ("x = 1;")
+%! assert (x,1);
+
+%!test
+%! eval ("flipud = 2;");
+%! assert (flipud, 2);
+
+%!function y = __f ()
+%!  eval ("flipud = 2;");
+%!  y = flipud;
+%!endfunction
+%!assert (__f(), 2)
+
+% bug #35645
+%!test
+%! [a,] = gcd (1,2);
+%! [a,b,] = gcd (1, 2);
+
+*/
+
+DEFUN (assignin, args, ,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {} assignin (@var{context}, @var{varname}, @var{value})\n\
+Assign @var{value} to @var{varname} in context @var{context}, which\n\
+may be either @code{\"base\"} or @code{\"caller\"}.\n\
+@seealso{evalin}\n\
+@end deftypefn")
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin == 3)
+    {
+      std::string context = args(0).string_value ();
+
+      if (! error_state)
+        {
+          unwind_protect frame;
+
+          if (context == "caller")
+            octave_call_stack::goto_caller_frame ();
+          else if (context == "base")
+            octave_call_stack::goto_base_frame ();
+          else
+            error ("assignin: CONTEXT must be \"caller\" or \"base\"");
+
+          if (! error_state)
+            {
+              frame.add_fcn (octave_call_stack::pop);
+
+              std::string nm = args(1).string_value ();
+
+              if (! error_state)
+                {
+                  if (valid_identifier (nm))
+                    symbol_table::varref (nm) = args(2);
+                  else
+                    error ("assignin: invalid variable name in argument VARNAME");
+                }
+              else
+                error ("assignin: VARNAME must be a string");
+            }
+        }
+      else
+        error ("assignin: CONTEXT must be a string");
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+DEFUN (evalin, args, nargout,
+  "-*- texinfo -*-\n\
+@deftypefn  {Built-in Function} {} evalin (@var{context}, @var{try})\n\
+@deftypefnx {Built-in Function} {} evalin (@var{context}, @var{try}, @var{catch})\n\
+Like @code{eval}, except that the expressions are evaluated in the\n\
+context @var{context}, which may be either @code{\"caller\"} or\n\
+@code{\"base\"}.\n\
+@seealso{eval, assignin}\n\
+@end deftypefn")
+{
+  octave_value_list retval;
+
+  int nargin = args.length ();
+
+  if (nargin > 1)
+    {
+      std::string context = args(0).string_value ();
+
+      if (! error_state)
+        {
+          unwind_protect frame;
+
+          if (context == "caller")
+            octave_call_stack::goto_caller_frame ();
+          else if (context == "base")
+            octave_call_stack::goto_base_frame ();
+          else
+            error ("evalin: CONTEXT must be \"caller\" or \"base\"");
+
+          if (! error_state)
+            {
+              frame.add_fcn (octave_call_stack::pop);
+
+              if (nargin > 2)
+                {
+                  frame.protect_var (buffer_error_messages);
+                  buffer_error_messages++;
+                }
+
+              int parse_status = 0;
+
+              octave_value_list tmp = eval_string (args(1), nargout > 0,
+                                                   parse_status, nargout);
+
+              if (nargout > 0)
+                retval = tmp;
+
+              if (nargin > 2 && (parse_status != 0 || error_state))
+                {
+                  error_state = 0;
+
+                  // Set up for letting the user print any messages from
+                  // errors that occurred in the first part of this eval().
+
+                  buffer_error_messages--;
+
+                  tmp = eval_string (args(2), nargout > 0,
+                                     parse_status, nargout);
+
+                  retval = (nargout > 0) ? tmp : octave_value_list ();
+                }
+            }
+        }
+      else
+        error ("evalin: CONTEXT must be a string");
+    }
+  else
+    print_usage ();
+
+  return retval;
+}
+
+DEFUN (__parser_debug_flag__, args, nargout,
+  "-*- texinfo -*-\n\
+@deftypefn {Built-in Function} {@var{old_val} =} __parser_debug_flag__ (@var{new_val}))\n\
+Undocumented internal function.\n\
+@end deftypefn")
+{
+  octave_value retval;
+
+  bool debug_flag = octave_debug;
+
+  retval = set_internal_variable (debug_flag, args, nargout,
+                                  "__parser_debug_flag__");
+
+  octave_debug = debug_flag;
+
+  return retval;
+}