Mercurial > octave-libtiff
view libinterp/octave-value/ov-null-mat.cc @ 23219:3ac9f9ecfae5 stable
maint: Update copyright dates.
author | John W. Eaton <jwe@octave.org> |
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date | Wed, 22 Feb 2017 12:39:29 -0500 |
parents | e9a0469dedd9 |
children | 092078913d54 |
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/* Copyright (C) 2008-2017 Jaroslav Hajek 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 (HAVE_CONFIG_H) # include "config.h" #endif #include "ov-null-mat.h" #include "ops.h" #include "defun.h" DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_null_matrix, "null_matrix", "double"); const octave_value octave_null_matrix::instance (new octave_null_matrix ()); static octave_base_value * default_null_matrix_numeric_conversion_function (const octave_base_value& a) { // The cast is not necessary? // const octave_null_matrix& v = dynamic_cast<const octave_null_matrix&> (a); return a.empty_clone (); } octave_base_value::type_conv_info octave_null_matrix::numeric_conversion_function (void) const { return octave_base_value::type_conv_info (default_null_matrix_numeric_conversion_function, octave_matrix::static_type_id ()); } DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_null_str, "null_string", "char"); const octave_value octave_null_str::instance (new octave_null_str ()); static octave_base_value * default_null_str_numeric_conversion_function (const octave_base_value& a) { // The cast is not necessary? // const octave_null_str& v = dynamic_cast<const octave_null_str&> (a); return a.empty_clone (); } octave_base_value::type_conv_info octave_null_str::numeric_conversion_function (void) const { return octave_base_value::type_conv_info (default_null_str_numeric_conversion_function, octave_char_matrix_str::static_type_id ()); } DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_null_sq_str, "null_sq_string", "char"); const octave_value octave_null_sq_str::instance (new octave_null_sq_str ()); static octave_base_value * default_null_sq_str_numeric_conversion_function (const octave_base_value& a) { // The cast is not necessary? // const octave_null_sq_str& v = dynamic_cast<const octave_null_sq_str&> (a); return a.empty_clone (); } octave_base_value::type_conv_info octave_null_sq_str::numeric_conversion_function (void) const { return octave_base_value::type_conv_info (default_null_sq_str_numeric_conversion_function, octave_char_matrix_sq_str::static_type_id ()); } DEFUN (isnull, args, , doc: /* -*- texinfo -*- @deftypefn {} {} isnull (@var{x}) Return true if @var{x} is a special null matrix, string, or single quoted string. Indexed assignment with such a value on the right-hand side should delete array elements. This function should be used when overloading indexed assignment for user-defined classes instead of @code{isempty}, to distinguish the cases: @table @asis @item @code{A(I) = []} This should delete elements if @code{I} is nonempty. @item @code{X = []; A(I) = X} This should give an error if @code{I} is nonempty. @end table @seealso{isempty, isindex} @end deftypefn */) { if (args.length () != 1) print_usage (); return ovl (args(0).is_null_value ()); } /* %!assert (isnull ([]), true) %!assert (isnull ([1]), false) %!assert (isnull (zeros (0,3)), false) %!assert (isnull (""), true) %!assert (isnull ("A"), false) %!assert (isnull (''), true) %!assert (isnull ('A'), false) %!test %! x = []; %! assert (isnull (x), false); */