Added special-case logical-indexing function * logical-index.h (New file) : Logical-indexing function. May be called on octave_value types via call_bool_index * nz-iterators.h : Add base-class nz_iterator for iterator types. Array has template bool for whether to internally store row-col or compute on the fly Add skip_ahead method which skips forward to the next nonzero after its argument Add flat_index for computing octave_idx_type index of current position (with assertion failure in the case of overflow) Move is_zero to separate file * ov-base-diag.cc, ov-base-mat.cc, ov-base-sparse.cc, ov-perm.cc (do_index_op): Add call to call_bool_index in logical-index.h * Array.h : Move forward-declaration for array_iterator to separate header file * dim-vector.cc (dim_max): Refers to idx-bounds.h (max_idx) * array-iter-decl.h (New file): Header file for forward declaration of array-iterator * direction.h : Add constants fdirc and bdirc to avoid having to reconstruct them * dv-utils.h, dv-utils.cc (New files) : Utility functions for querying and constructing dim-vectors * idx-bounds.h (New file) : Utility constants and functions for determining whether things will overflow the maximum allowed bounds * interp-idx.h (New function : to_flat_idx) : Converts row-col pair to linear index of octave_idx_type * is-zero.h (New file) : Function for determining whether an element is zero * logical-index.tst : Add tests for correct return-value dimensions and large sparse matrix behavior

## Copyright (C) 2014 Andreas Weber
##
## 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/>.

## -*- texinfo -*-
## @deftypefn {Function File} {@var{funcname} =} __get_funcname__ (@var{basename})
## Internal function.
##
## Build function name for the current graphics toolkit according to schema
## __[basename]_[graphics_toolkit]__, use fltk as default.
## @end deftypefn

## Author: Andreas Weber

function funcname = __get_funcname__ (basename)

  if (! __octave_link_enabled__ ())
    tk = graphics_toolkit ();
    funcname = strcat ("__", basename, "_", tk, "__");
    if ((numel (tk) > 0) && (! strcmp(tk, "fltk")) && (! __is_function__ (funcname)))
      warning ("%s: no implementation for toolkit '%s', using 'fltk' instead",basename, tk);
    endif
    funcname = strcat ("__", basename, "_fltk__");
  else
    funcname = "";
  endif

endfunction