# HG changeset patch
# User Jaroslav Hajek <address@hidden>
# Date 1270545114 -7200
# Node ID 806cfe2c81a37bfb381a497177e34379ff92fb23
# Parent  d47802f0e55712f0aeaa3e0f51d3349a81953925
allow non-integer ranges as indices conditionally

diff --git a/src/ChangeLog b/src/ChangeLog
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -0,0 +1,9 @@
+2010-04-06  Jaroslav Hajek  <address@hidden>
+
+	* ov-range.cc (allow_noninteger_ranges_as_indices): New internal
+	variable.
+	(octave_range::index_vector): Use it here to possibly allow
+	non-integer ranges.
+	* ov-range.h: Declare it.
+	* utils.cc (Fisindex): Temporarily disable it here.
+
diff --git a/src/octave.cc b/src/octave.cc
--- a/src/octave.cc
+++ b/src/octave.cc
@@ -572,6 +572,7 @@
                          "%%-- %D %I:%M %p --%%");
   bind_internal_variable ("page_screen_output", false);
   bind_internal_variable ("print_empty_dimensions", false);
+  bind_internal_variable ("allow_noninteger_ranges_as_indices", true);
 
   disable_warning ("Octave:abbreviated-property-match");
   disable_warning ("Octave:fopen-file-in-path");
diff --git a/src/ov-range.cc b/src/ov-range.cc
--- a/src/ov-range.cc
+++ b/src/ov-range.cc
@@ -30,6 +30,8 @@
 #include "lo-ieee.h"
 #include "lo-utils.h"
 
+#include "defun.h"
+#include "variables.h"
 #include "gripes.h"
 #include "ops.h"
 #include "oct-obj.h"
@@ -47,6 +49,8 @@
 
 DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_range, "range", "double");
 
+bool Vallow_noninteger_ranges_as_indices = false;
+
 static octave_base_value *
 default_numeric_conversion_function (const octave_base_value& a)
 {
@@ -142,6 +146,20 @@
     }
 }
 
+idx_vector
+octave_range::index_vector (void) const
+{
+  if (idx_cache)
+    return *idx_cache;
+  else if (! Vallow_noninteger_ranges_as_indices)
+    return set_idx_cache (idx_vector (range));
+  else
+    {
+      warning ("Non-integer range used as index. Values are rounded to nearest integer.");
+      return octave_value (matrix_value ()).round ().index_vector ();
+    }
+}
+
 double
 octave_range::double_value (bool) const
 {
@@ -568,3 +586,15 @@
 
   return retval;
 }
+
+DEFUN (allow_noninteger_ranges_as_indices, args, nargout,
+    "-*- texinfo -*-\n\
address@hidden {Built-in Function} address@hidden =} allow_noninteger_ranges_as_indices ()\n\
address@hidden {Built-in Function} address@hidden =} allow_noninteger_ranges_as_indices (@var{new_val})\n\
+Query or set the internal variable that controls whether non-integer ranges are allowed as indices.\n\
+This might be useful for Matlab compatibility; however, it is still not entirely compatible\n\
+because Matlab treats the range expression differently in different contexts.\n\
address@hidden deftypefn")
+{
+  return SET_INTERNAL_VARIABLE (allow_noninteger_ranges_as_indices);
+}
diff --git a/src/ov-range.h b/src/ov-range.h
--- a/src/ov-range.h
+++ b/src/ov-range.h
@@ -50,6 +50,8 @@
 
 // Range values.
 
+extern OCTINTERP_API bool Vallow_noninteger_ranges_as_indices;
+
 class
 octave_range : public octave_base_value
 {
@@ -106,8 +108,7 @@
   octave_value do_index_op (const octave_value_list& idx,
                             bool resize_ok = false);
 
-  idx_vector index_vector (void) const 
-    { return idx_cache ? *idx_cache : set_idx_cache (idx_vector (range)); }
+  idx_vector index_vector (void) const;
 
   dim_vector dims (void) const
     { 
diff --git a/src/utils.cc b/src/utils.cc
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -64,6 +64,7 @@
 #include "unwind-prot.h"
 #include "utils.h"
 #include "variables.h"
+#include "ov-range.h"
 
 // Return TRUE if S is a valid identifier.
 
@@ -1324,6 +1325,8 @@
   if (! error_state)
     {
       unwind_protect frame;
+      frame.protect_var (Vallow_noninteger_ranges_as_indices);
+      Vallow_noninteger_ranges_as_indices = false;
       frame.protect_var (error_state);
       frame.protect_var (discard_error_messages);
       discard_error_messages = true;