--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/liboctave/array/idx-vector.h	Fri Aug 31 20:00:20 2012 -0700
@@ -0,0 +1,1050 @@
+/*
+
+Copyright (C) 1993-2012 John W. Eaton
+Copyright (C) 2008-2009 Jaroslav Hajek
+Copyright (C) 2009 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/>.
+
+*/
+
+#if !defined (octave_idx_vector_h)
+#define octave_idx_vector_h 1
+
+#include <cassert>
+
+#include <algorithm>
+#include <iosfwd>
+#include <memory>
+
+#include "dim-vector.h"
+#include "oct-inttypes.h"
+#include "oct-alloc.h"
+#include "oct-mem.h"
+#include "oct-refcount.h"
+
+template<class T> class Array;
+template<class T> class Sparse;
+class Range;
+
+// Design rationale:
+// idx_vector is a reference-counting, polymorphic pointer, that can contain
+// 4 types of index objects: a magic colon, a range, a scalar, or an index vector.
+// Polymorphic methods for single element access are provided, as well as
+// templates implementing "early dispatch", i.e. hoisting the checks for index
+// type out of loops.
+
+class
+OCTAVE_API
+idx_vector
+{
+public:
+
+  enum idx_class_type
+    {
+      class_invalid = -1,
+      class_colon = 0,
+      class_range,
+      class_scalar,
+      class_vector,
+      class_mask
+    };
+
+  template<class T> friend class std::auto_ptr;
+
+private:
+
+  class OCTAVE_API idx_base_rep
+  {
+  public:
+    idx_base_rep (void) : count (1), err (false) { }
+
+    virtual ~idx_base_rep (void) { }
+
+    // Non-range-checking element query.
+    virtual octave_idx_type xelem (octave_idx_type i) const = 0;
+
+    // Range-checking element query.
+    virtual octave_idx_type checkelem (octave_idx_type i) const = 0;
+
+    // Length of the index vector.
+    virtual octave_idx_type length (octave_idx_type n) const = 0;
+
+    // The maximum index + 1. The actual dimension is passed in.
+    virtual octave_idx_type extent (octave_idx_type n) const = 0;
+
+    // Index class.
+    virtual idx_class_type idx_class (void) const { return class_invalid; }
+
+    // Sorts, maybe uniqifies, and returns a clone object pointer.
+    virtual idx_base_rep *sort_uniq_clone (bool uniq = false) = 0;
+    // Sorts, and returns a sorting permutation (aka Array::sort).
+    virtual idx_base_rep *sort_idx (Array<octave_idx_type>&) = 0;
+
+    // Checks whether the index is colon or a range equivalent to colon.
+    virtual bool is_colon_equiv (octave_idx_type) const { return false; }
+
+    // The original dimensions of this object (used when subscribing by matrices).
+    virtual dim_vector orig_dimensions (void) const { return dim_vector (); }
+
+    // i/o
+    virtual std::ostream& print (std::ostream& os) const = 0;
+
+    virtual Array<octave_idx_type> as_array (void);
+
+    octave_refcount<int> count;
+
+    bool err;
+
+  private:
+
+    // No copying!
+    idx_base_rep (const idx_base_rep&);
+    idx_base_rep& operator = (const idx_base_rep&);
+  };
+
+  // The magic colon index.
+  class OCTAVE_API idx_colon_rep : public idx_base_rep
+  {
+  public:
+    idx_colon_rep (void) { }
+
+    idx_colon_rep (char c);
+
+    octave_idx_type xelem (octave_idx_type i) const { return i; }
+
+    octave_idx_type checkelem (octave_idx_type i) const;
+
+    octave_idx_type length (octave_idx_type n) const { return n; }
+
+    octave_idx_type extent (octave_idx_type n) const { return n; }
+
+    idx_class_type idx_class (void) const { return class_colon; }
+
+    idx_base_rep *sort_uniq_clone (bool = false)
+      { count++; return this; }
+
+    idx_base_rep *sort_idx (Array<octave_idx_type>&);
+
+    bool is_colon_equiv (octave_idx_type) const { return true; }
+
+    std::ostream& print (std::ostream& os) const;
+
+  private:
+
+    DECLARE_OCTAVE_ALLOCATOR
+
+    // No copying!
+    idx_colon_rep (const idx_colon_rep& idx);
+    idx_colon_rep& operator = (const idx_colon_rep& idx);
+  };
+
+  // To distinguish the "direct" constructors that blindly trust the data.
+  enum direct { DIRECT };
+
+  // The integer range index.
+  class OCTAVE_API idx_range_rep : public idx_base_rep
+  {
+  public:
+    idx_range_rep (octave_idx_type _start, octave_idx_type _len,
+                   octave_idx_type _step, direct)
+      : idx_base_rep (), start(_start), len(_len), step(_step) { }
+
+    idx_range_rep (void)
+      : start(0), len(0), step(1) { }
+
+    // Zero-based constructor.
+    idx_range_rep (octave_idx_type _start, octave_idx_type _limit,
+                   octave_idx_type _step);
+
+    idx_range_rep (const Range&);
+
+    octave_idx_type xelem (octave_idx_type i) const
+      { return start + i * step; }
+
+    octave_idx_type checkelem (octave_idx_type i) const;
+
+    octave_idx_type length (octave_idx_type) const { return len; }
+
+    octave_idx_type extent (octave_idx_type n) const
+      { return len ? std::max (n, (start + 1 + (step < 0 ? 0 : step * (len - 1)))) : n; }
+
+    idx_class_type idx_class (void) const { return class_range; }
+
+    idx_base_rep *sort_uniq_clone (bool uniq = false);
+
+    idx_base_rep *sort_idx (Array<octave_idx_type>&);
+
+    bool is_colon_equiv (octave_idx_type n) const
+      { return start == 0 && step == 1 && len == n; }
+
+    dim_vector orig_dimensions (void) const
+      { return dim_vector (1, len); }
+
+    octave_idx_type get_start (void) const { return start; }
+
+    octave_idx_type get_step (void) const { return step; }
+
+    std::ostream& print (std::ostream& os) const;
+
+    Range unconvert (void) const;
+
+    Array<octave_idx_type> as_array (void);
+
+  private:
+
+    DECLARE_OCTAVE_ALLOCATOR
+
+    // No copying!
+    idx_range_rep (const idx_range_rep& idx);
+    idx_range_rep& operator = (const idx_range_rep& idx);
+
+    octave_idx_type start, len, step;
+
+  };
+
+  // The integer scalar index.
+  class OCTAVE_API idx_scalar_rep : public idx_base_rep
+  {
+  public:
+    idx_scalar_rep (octave_idx_type i, direct)
+      : data (i) { }
+
+    idx_scalar_rep (void)
+      : data (0) { }
+
+    // Zero-based constructor.
+    idx_scalar_rep (octave_idx_type i);
+
+    template <class T>
+    idx_scalar_rep (T x);
+
+    octave_idx_type xelem (octave_idx_type) const { return data; }
+
+    octave_idx_type checkelem (octave_idx_type i) const;
+
+    octave_idx_type length (octave_idx_type) const { return 1; }
+
+    octave_idx_type extent (octave_idx_type n) const
+      { return std::max (n, data + 1); }
+
+    idx_class_type idx_class (void) const { return class_scalar; }
+
+    idx_base_rep *sort_uniq_clone (bool = false)
+      { count++; return this; }
+
+    idx_base_rep *sort_idx (Array<octave_idx_type>&);
+
+    bool is_colon_equiv (octave_idx_type n) const
+      { return n == 1 && data == 0; }
+
+    dim_vector orig_dimensions (void) const { return dim_vector (1, 1); }
+
+    octave_idx_type get_data (void) const { return data; }
+
+    std::ostream& print (std::ostream& os) const;
+
+    double unconvert (void) const;
+
+    Array<octave_idx_type> as_array (void);
+
+  private:
+
+    DECLARE_OCTAVE_ALLOCATOR
+
+    // No copying!
+    idx_scalar_rep (const idx_scalar_rep& idx);
+    idx_scalar_rep& operator = (const idx_scalar_rep& idx);
+
+    octave_idx_type data;
+
+  };
+
+  // The integer vector index.
+  class OCTAVE_API idx_vector_rep : public idx_base_rep
+  {
+  public:
+    // Direct constructor.
+    idx_vector_rep (octave_idx_type *_data, octave_idx_type _len,
+                    octave_idx_type _ext, const dim_vector& od, direct)
+      : data (_data), len (_len), ext (_ext), aowner (0), orig_dims (od) { }
+
+    idx_vector_rep (void)
+      : data (0), len (0), ext (0), aowner (0), orig_dims ()
+      { }
+
+    // Zero-based constructor.
+    idx_vector_rep (const Array<octave_idx_type>& inda);
+
+    idx_vector_rep (const Array<octave_idx_type>& inda,
+                    octave_idx_type _ext, direct);
+
+    template <class T>
+    idx_vector_rep (const Array<T>&);
+
+    idx_vector_rep (bool);
+
+    idx_vector_rep (const Array<bool>&, octave_idx_type = -1);
+
+    idx_vector_rep (const Sparse<bool>&);
+
+    ~idx_vector_rep (void);
+
+    octave_idx_type xelem (octave_idx_type i) const { return data[i]; }
+
+    octave_idx_type checkelem (octave_idx_type i) const;
+
+    octave_idx_type length (octave_idx_type) const { return len; }
+
+    octave_idx_type extent (octave_idx_type n) const
+      { return std::max (n, ext); }
+
+    idx_class_type idx_class (void) const { return class_vector; }
+
+    idx_base_rep *sort_uniq_clone (bool uniq = false);
+
+    idx_base_rep *sort_idx (Array<octave_idx_type>&);
+
+    dim_vector orig_dimensions (void) const { return orig_dims; }
+
+    const octave_idx_type *get_data (void) const { return data; }
+
+    std::ostream& print (std::ostream& os) const;
+
+    Array<double> unconvert (void) const;
+
+    Array<octave_idx_type> as_array (void);
+
+  private:
+
+    DECLARE_OCTAVE_ALLOCATOR
+
+    // No copying!
+    idx_vector_rep (const idx_vector_rep& idx);
+    idx_vector_rep& operator = (const idx_vector_rep& idx);
+
+    const octave_idx_type *data;
+    octave_idx_type len;
+    octave_idx_type ext;
+
+    // This is a trick to allow user-given zero-based arrays to be used
+    // as indices without copying.  If the following pointer is nonzero,
+    // we do not own the data, but rather have an Array<octave_idx_type>
+    // object that provides us the data.  Note that we need a pointer
+    // because we deferred the Array<T> declaration and we do not want
+    // it yet to be defined.
+
+    Array<octave_idx_type> *aowner;
+
+    dim_vector orig_dims;
+  };
+
+  // The logical mask index.
+  class OCTAVE_API idx_mask_rep : public idx_base_rep
+  {
+  public:
+    // Direct constructor.
+    idx_mask_rep (bool *_data, octave_idx_type _len,
+                  octave_idx_type _ext, const dim_vector& od, direct)
+      : data (_data), len (_len), ext (_ext), lsti (-1), lste (-1),
+        aowner (0), orig_dims (od) { }
+
+    idx_mask_rep (void)
+      : data (0), len (0), ext (0), lsti (-1), lste (-1), aowner (0),
+        orig_dims ()
+      { }
+
+    idx_mask_rep (bool);
+
+    idx_mask_rep (const Array<bool>&, octave_idx_type = -1);
+
+    ~idx_mask_rep (void);
+
+    octave_idx_type xelem (octave_idx_type i) const;
+
+    octave_idx_type checkelem (octave_idx_type i) const;
+
+    octave_idx_type length (octave_idx_type) const { return len; }
+
+    octave_idx_type extent (octave_idx_type n) const
+      { return std::max (n, ext); }
+
+    idx_class_type idx_class (void) const { return class_mask; }
+
+    idx_base_rep *sort_uniq_clone (bool = false)
+      { count++; return this; }
+
+    idx_base_rep *sort_idx (Array<octave_idx_type>&);
+
+    dim_vector orig_dimensions (void) const { return orig_dims; }
+
+    bool is_colon_equiv (octave_idx_type n) const
+      { return len == n && ext == n; }
+
+    const bool *get_data (void) const { return data; }
+
+    std::ostream& print (std::ostream& os) const;
+
+    Array<bool> unconvert (void) const;
+
+    Array<octave_idx_type> as_array (void);
+
+  private:
+
+    DECLARE_OCTAVE_ALLOCATOR
+
+    // No copying!
+    idx_mask_rep (const idx_mask_rep& idx);
+    idx_mask_rep& operator = (const idx_mask_rep& idx);
+
+    const bool *data;
+    octave_idx_type len;
+    octave_idx_type ext;
+
+    // FIXME: I'm not sure if this is a good design. Maybe it would be
+    // better to employ some sort of generalized iteration scheme.
+    mutable octave_idx_type lsti;
+    mutable octave_idx_type lste;
+
+    // This is a trick to allow user-given mask arrays to be used as
+    // indices without copying.  If the following pointer is nonzero, we
+    // do not own the data, but rather have an Array<bool> object that
+    // provides us the data.  Note that we need a pointer because we
+    // deferred the Array<T> declaration and we do not want it yet to be
+    // defined.
+
+    Array<bool> *aowner;
+
+    dim_vector orig_dims;
+  };
+
+  idx_vector (idx_base_rep *r) : rep (r) { }
+
+  // The shared empty vector representation (for fast default
+  // constructor).
+  static idx_vector_rep *nil_rep (void)
+    {
+      static idx_vector_rep ivr;
+      return &ivr;
+    }
+
+  // The shared empty vector representation with the error flag set.
+  static idx_vector_rep *err_rep (void)
+    {
+      static idx_vector_rep ivr;
+      ivr.err = true;
+      return &ivr;
+    }
+
+  // If there was an error in constructing the rep, replace it with
+  // empty vector for safety.
+  void chkerr (void)
+    {
+      if (rep->err)
+        {
+          if (--rep->count == 0)
+            delete rep;
+          rep = err_rep ();
+          rep->count++;
+        }
+    }
+
+public:
+
+  // Fast empty constructor.
+  idx_vector (void) : rep (nil_rep ()) { rep->count++; }
+
+  // Zero-based constructors (for use from C++).
+  idx_vector (octave_idx_type i) : rep (new idx_scalar_rep (i))
+    { chkerr (); }
+
+  idx_vector (octave_idx_type start, octave_idx_type limit,
+              octave_idx_type step = 1)
+    : rep (new idx_range_rep (start, limit, step))
+    { chkerr (); }
+
+  static idx_vector
+    make_range (octave_idx_type start, octave_idx_type step,
+                octave_idx_type len)
+    {
+      return idx_vector (new idx_range_rep (start, len, step, DIRECT));
+    }
+
+  idx_vector (const Array<octave_idx_type>& inda)
+    : rep (new idx_vector_rep (inda))
+    { chkerr (); }
+
+  // Directly pass extent, no checking.
+  idx_vector (const Array<octave_idx_type>& inda, octave_idx_type ext)
+    : rep (new idx_vector_rep (inda, ext, DIRECT))
+    { }
+
+  // Colon is best constructed by simply copying (or referencing) this member.
+  static const idx_vector colon;
+
+  // or passing ':' here
+  idx_vector (char c) : rep (new idx_colon_rep (c)) { chkerr (); }
+
+  // Conversion constructors (used by interpreter).
+
+  template <class T>
+  idx_vector (octave_int<T> x) : rep (new idx_scalar_rep (x)) { chkerr (); }
+
+  idx_vector (double x) : rep (new idx_scalar_rep (x)) { chkerr (); }
+
+  idx_vector (float x) : rep (new idx_scalar_rep (x)) { chkerr (); }
+
+  // A scalar bool does not necessarily map to scalar index.
+  idx_vector (bool x) : rep (new idx_mask_rep (x)) { chkerr (); }
+
+  template <class T>
+  idx_vector (const Array<octave_int<T> >& nda) : rep (new idx_vector_rep (nda))
+    { chkerr (); }
+
+  idx_vector (const Array<double>& nda) : rep (new idx_vector_rep (nda))
+    { chkerr (); }
+
+  idx_vector (const Array<float>& nda) : rep (new idx_vector_rep (nda))
+    { chkerr (); }
+
+  idx_vector (const Array<bool>& nda);
+
+  idx_vector (const Range& r)
+    : rep (new idx_range_rep (r))
+    { chkerr (); }
+
+  idx_vector (const Sparse<bool>& nda) : rep (new idx_vector_rep (nda))
+    { chkerr (); }
+
+  idx_vector (const idx_vector& a) : rep (a.rep) { rep->count++; }
+
+  ~idx_vector (void)
+    {
+      if (--rep->count == 0)
+        delete rep;
+    }
+
+  idx_vector& operator = (const idx_vector& a)
+    {
+      if (this != &a)
+        {
+          if (--rep->count == 0)
+            delete rep;
+
+          rep = a.rep;
+          rep->count++;
+        }
+      return *this;
+    }
+
+  idx_class_type idx_class (void) const { return rep->idx_class (); }
+
+  octave_idx_type length (octave_idx_type n = 0) const
+    { return rep->length (n); }
+
+  octave_idx_type extent (octave_idx_type n) const
+    { return rep->extent (n); }
+
+  octave_idx_type xelem (octave_idx_type n) const
+    { return rep->xelem (n); }
+
+  octave_idx_type checkelem (octave_idx_type n) const
+    { return rep->checkelem (n); }
+
+  octave_idx_type operator () (octave_idx_type n) const
+    {
+#if defined (BOUNDS_CHECKING)
+      return rep->checkelem (n);
+#else
+      return rep->xelem (n);
+#endif
+    }
+
+  operator bool (void) const
+    { return ! rep->err; }
+
+  bool is_colon (void) const
+    { return rep->idx_class () == class_colon; }
+
+  bool is_scalar (void) const
+    { return rep->idx_class () == class_scalar; }
+
+  bool is_range (void) const
+    { return rep->idx_class () == class_range; }
+
+  bool is_colon_equiv (octave_idx_type n) const
+    { return rep->is_colon_equiv (n); }
+
+  idx_vector sorted (bool uniq = false) const
+    { return idx_vector (rep->sort_uniq_clone (uniq)); }
+
+  idx_vector sorted (Array<octave_idx_type>& sidx) const
+    { return idx_vector (rep->sort_idx (sidx)); }
+
+  dim_vector orig_dimensions (void) const { return rep->orig_dimensions (); }
+
+  octave_idx_type orig_rows (void) const
+    { return orig_dimensions () (0); }
+
+  octave_idx_type orig_columns (void) const
+    { return orig_dimensions () (1); }
+
+  int orig_empty (void) const
+    { return (! is_colon () && orig_dimensions ().any_zero ()); }
+
+  // i/o
+
+  std::ostream& print (std::ostream& os) const { return rep->print (os); }
+
+  friend std::ostream& operator << (std::ostream& os, const idx_vector& a)
+    { return a.print (os); }
+
+  // Slice with specializations. No checking of bounds!
+  //
+  // This is equivalent to the following loop (but much faster):
+  //
+  // for (octave_idx_type i = 0; i < idx->length (n); i++)
+  //   dest[i] = src[idx(i)];
+  // return i;
+  //
+  template <class T>
+  octave_idx_type
+  index (const T *src, octave_idx_type n, T *dest) const
+    {
+      octave_idx_type len = rep->length (n);
+
+      switch (rep->idx_class ())
+        {
+        case class_colon:
+          copy_or_memcpy (len, src, dest);
+          break;
+
+        case class_range:
+          {
+            idx_range_rep * r = dynamic_cast<idx_range_rep *> (rep);
+            octave_idx_type start = r->get_start (), step = r->get_step ();
+            const T *ssrc = src + start;
+            if (step == 1)
+              copy_or_memcpy (len, ssrc, dest);
+            else if (step == -1)
+              std::reverse_copy (ssrc - len + 1, ssrc + 1, dest);
+            else if (step == 0)
+              std::fill_n (dest, len, *ssrc);
+            else
+              {
+                for (octave_idx_type i = 0, j = 0; i < len; i++, j += step)
+                  dest[i] = ssrc[j];
+              }
+          }
+          break;
+
+        case class_scalar:
+          {
+            idx_scalar_rep * r = dynamic_cast<idx_scalar_rep *> (rep);
+            dest[0] = src[r->get_data ()];
+          }
+          break;
+
+        case class_vector:
+          {
+            idx_vector_rep * r = dynamic_cast<idx_vector_rep *> (rep);
+            const octave_idx_type *data = r->get_data ();
+            for (octave_idx_type i = 0; i < len; i++)
+              dest[i] = src[data[i]];
+          }
+          break;
+
+        case class_mask:
+          {
+            idx_mask_rep * r = dynamic_cast<idx_mask_rep *> (rep);
+            const bool *data = r->get_data ();
+            octave_idx_type ext = r->extent (0);
+            for (octave_idx_type i = 0; i < ext; i++)
+              if (data[i]) *dest++ = src[i];
+          }
+          break;
+
+        default:
+          assert (false);
+          break;
+        }
+
+      return len;
+    }
+
+  // Slice assignment with specializations. No checking of bounds!
+  //
+  // This is equivalent to the following loop (but much faster):
+  //
+  // for (octave_idx_type i = 0; i < idx->length (n); i++)
+  //   dest[idx(i)] = src[i];
+  // return i;
+  //
+  template <class T>
+  octave_idx_type
+  assign (const T *src, octave_idx_type n, T *dest) const
+    {
+      octave_idx_type len = rep->length (n);
+
+      switch (rep->idx_class ())
+        {
+        case class_colon:
+          copy_or_memcpy (len, src, dest);
+          break;
+
+        case class_range:
+          {
+            idx_range_rep * r = dynamic_cast<idx_range_rep *> (rep);
+            octave_idx_type start = r->get_start (), step = r->get_step ();
+            T *sdest = dest + start;
+            if (step == 1)
+              copy_or_memcpy (len, src, sdest);
+            else if (step == -1)
+              std::reverse_copy (src, src + len, sdest - len + 1);
+            else
+              {
+                for (octave_idx_type i = 0, j = 0; i < len; i++, j += step)
+                  sdest[j] = src[i];
+              }
+          }
+          break;
+
+        case class_scalar:
+          {
+            idx_scalar_rep * r = dynamic_cast<idx_scalar_rep *> (rep);
+            dest[r->get_data ()] = src[0];
+          }
+          break;
+
+        case class_vector:
+          {
+            idx_vector_rep * r = dynamic_cast<idx_vector_rep *> (rep);
+            const octave_idx_type *data = r->get_data ();
+            for (octave_idx_type i = 0; i < len; i++)
+              dest[data[i]] = src[i];
+          }
+          break;
+
+        case class_mask:
+          {
+            idx_mask_rep * r = dynamic_cast<idx_mask_rep *> (rep);
+            const bool *data = r->get_data ();
+            octave_idx_type ext = r->extent (0);
+            for (octave_idx_type i = 0; i < ext; i++)
+              if (data[i]) dest[i] = *src++;
+          }
+          break;
+
+        default:
+          assert (false);
+          break;
+        }
+
+      return len;
+    }
+
+  // Slice fill with specializations. No checking of bounds!
+  //
+  // This is equivalent to the following loop (but much faster):
+  //
+  // for (octave_idx_type i = 0; i < idx->length (n); i++)
+  //   dest[idx(i)] = val;
+  // return i;
+  //
+  template <class T>
+  octave_idx_type
+  fill (const T& val, octave_idx_type n, T *dest) const
+    {
+      octave_idx_type len = rep->length (n);
+
+      switch (rep->idx_class ())
+        {
+        case class_colon:
+          std::fill (dest, dest + len, val);
+          break;
+
+        case class_range:
+          {
+            idx_range_rep * r = dynamic_cast<idx_range_rep *> (rep);
+            octave_idx_type start = r->get_start (), step = r->get_step ();
+            T *sdest = dest + start;
+            if (step == 1)
+              std::fill (sdest, sdest + len, val);
+            else if (step == -1)
+              std::fill (sdest - len + 1, sdest + 1, val);
+            else
+              {
+                for (octave_idx_type i = 0, j = 0; i < len; i++, j += step)
+                  sdest[j] = val;
+              }
+          }
+          break;
+
+        case class_scalar:
+          {
+            idx_scalar_rep * r = dynamic_cast<idx_scalar_rep *> (rep);
+            dest[r->get_data ()] = val;
+          }
+          break;
+
+        case class_vector:
+          {
+            idx_vector_rep * r = dynamic_cast<idx_vector_rep *> (rep);
+            const octave_idx_type *data = r->get_data ();
+            for (octave_idx_type i = 0; i < len; i++)
+              dest[data[i]] = val;
+          }
+          break;
+
+        case class_mask:
+          {
+            idx_mask_rep * r = dynamic_cast<idx_mask_rep *> (rep);
+            const bool *data = r->get_data ();
+            octave_idx_type ext = r->extent (0);
+            for (octave_idx_type i = 0; i < ext; i++)
+              if (data[i]) dest[i] = val;
+          }
+          break;
+
+        default:
+          assert (false);
+          break;
+        }
+
+      return len;
+    }
+
+  // Generic non-breakable indexed loop. The loop body should be
+  // encapsulated in a single functor body.  This is equivalent to the
+  // following loop (but faster, at least for simple inlined bodies):
+  //
+  // for (octave_idx_type i = 0; i < idx->length (n); i++) body (idx(i));
+
+  template <class Functor>
+  void
+  loop (octave_idx_type n, Functor body) const
+    {
+      octave_idx_type len = rep->length (n);
+
+      switch (rep->idx_class ())
+        {
+        case class_colon:
+          for (octave_idx_type i = 0; i < len; i++) body (i);
+          break;
+
+        case class_range:
+          {
+            idx_range_rep * r = dynamic_cast<idx_range_rep *> (rep);
+            octave_idx_type start = r->get_start (), step = r->get_step ();
+            octave_idx_type i, j;
+            if (step == 1)
+              for (i = start, j = start + len; i < j; i++) body (i);
+            else if (step == -1)
+              for (i = start, j = start - len; i > j; i--) body (i);
+            else
+              for (i = 0, j = start; i < len; i++, j += step) body (j);
+          }
+          break;
+
+        case class_scalar:
+          {
+            idx_scalar_rep * r = dynamic_cast<idx_scalar_rep *> (rep);
+            body (r->get_data ());
+          }
+          break;
+
+        case class_vector:
+          {
+            idx_vector_rep * r = dynamic_cast<idx_vector_rep *> (rep);
+            const octave_idx_type *data = r->get_data ();
+            for (octave_idx_type i = 0; i < len; i++) body (data[i]);
+          }
+          break;
+
+        case class_mask:
+          {
+            idx_mask_rep * r = dynamic_cast<idx_mask_rep *> (rep);
+            const bool *data = r->get_data ();
+            octave_idx_type ext = r->extent (0);
+            for (octave_idx_type i = 0; i < ext; i++)
+              if (data[i]) body (i);
+          }
+          break;
+
+        default:
+          assert (false);
+          break;
+        }
+
+    }
+
+  // Generic breakable indexed loop. The loop body should be
+  // encapsulated in a single functor body.  This is equivalent to the
+  // following loop (but faster, at least for simple inlined bodies):
+  //
+  // for (octave_idx_type i = 0; i < idx->length (n); i++)
+  //   if (body (idx(i))) break;
+  // return i;
+  //
+
+  template <class Functor>
+  octave_idx_type
+  bloop (octave_idx_type n, Functor body) const
+    {
+      octave_idx_type len = rep->length (n), ret;
+
+      switch (rep->idx_class ())
+        {
+        case class_colon:
+          {
+            octave_idx_type i;
+            for (i = 0; i < len && body (i); i++) ;
+            ret = i;
+          }
+          break;
+
+        case class_range:
+          {
+            idx_range_rep * r = dynamic_cast<idx_range_rep *> (rep);
+            octave_idx_type start = r->get_start (), step = r->get_step ();
+            octave_idx_type i, j;
+            if (step == 1)
+              for (i = start, j = start + len; i < j && body (i); i++) ;
+            else if (step == -1)
+              for (i = start, j = start - len; i > j && body (i); i--) ;
+            else
+              for (i = 0, j = start; i < len && body (j); i++, j += step) ;
+            ret = i;
+          }
+          break;
+
+        case class_scalar:
+          {
+            idx_scalar_rep * r = dynamic_cast<idx_scalar_rep *> (rep);
+            ret = body (r->get_data ()) ? 1 : 0;
+          }
+          break;
+
+        case class_vector:
+          {
+            idx_vector_rep * r = dynamic_cast<idx_vector_rep *> (rep);
+            const octave_idx_type *data = r->get_data ();
+            octave_idx_type i;
+            for (i = 0; i < len && body (data[i]); i++) ;
+            ret = i;
+          }
+          break;
+
+        case class_mask:
+          {
+            idx_mask_rep * r = dynamic_cast<idx_mask_rep *> (rep);
+            const bool *data = r->get_data ();
+            octave_idx_type ext = r->extent (0), j = 0;
+            for (octave_idx_type i = 0; i < ext; i++)
+              {
+                if (data[i])
+                  {
+                    if (body (i))
+                      break;
+                    else
+                      j++;
+                  }
+              }
+
+            ret = j;
+          }
+          break;
+
+        default:
+          assert (false);
+          break;
+        }
+
+      return ret;
+    }
+
+  // Rationale:
+  // This method is the key to "smart indexing". When indexing cartesian
+  // arrays, sometimes consecutive index vectors can be reduced into a
+  // single index.  If rows (A) = k and i.maybe_reduce (j) gives k, then
+  // A(i,j)(:) is equal to A(k)(:).
+
+  // If the next index can be reduced, returns true and updates this.
+  bool maybe_reduce (octave_idx_type n, const idx_vector& j,
+                     octave_idx_type nj);
+
+  bool is_cont_range (octave_idx_type n,
+                      octave_idx_type& l, octave_idx_type& u) const;
+
+  // Returns the increment for ranges and colon, 0 for scalars and empty
+  // vectors, 1st difference otherwise.
+  octave_idx_type increment (void) const;
+
+  idx_vector
+  complement (octave_idx_type n) const;
+
+  bool is_permutation (octave_idx_type n) const;
+
+  // Returns the inverse permutation. If this is not a permutation on 1:n, the
+  // result is undefined (but no error unless extent () != n).
+  idx_vector inverse_permutation (octave_idx_type n) const;
+
+  // Copies all the indices to a given array. Not allowed for colons.
+  void copy_data (octave_idx_type *data) const;
+
+  // If the index is a mask, convert it to index vector.
+  idx_vector unmask (void) const;
+
+  // Unconverts the index to a scalar, Range, double array or a mask.
+  void unconvert (idx_class_type& iclass,
+                  double& scalar, Range& range,
+                  Array<double>& array, Array<bool>& mask) const;
+
+  Array<octave_idx_type> as_array (void) const;
+
+  // Raw pointer to index array.  This is non-const because it may be
+  // necessary to mutate the index.
+  const octave_idx_type *raw (void);
+
+  bool is_vector (void) const;
+
+  // FIXME -- these are here for compatibility.  They should be removed
+  // when no longer in use.
+
+  octave_idx_type elem (octave_idx_type n) const
+    { return (*this) (n); }
+
+  bool is_colon_equiv (octave_idx_type n, int) const
+    { return is_colon_equiv (n); }
+
+  octave_idx_type
+  freeze (octave_idx_type z_len, const char *tag, bool resize_ok = false);
+
+  void sort (bool uniq = false)
+    { *this = sorted (uniq); }
+
+  octave_idx_type ones_count (void) const;
+
+  octave_idx_type max (void) const { return extent (1) - 1; }
+
+private:
+
+  idx_base_rep *rep;
+
+};
+
+#endif