# HG changeset patch
# User Andrew Janke <andrew@apjanke.net>
# Date 1548111140 18000
# Node ID 0f187a956d47b23067690340551118c5a0d6f0ba
# Parent  884fdd6c92104aea33c3193d2449974736cf4ca6
Add verLessThan function (bug #55525)

* verLessThan.m: New function.
* scripts/miscellaneous/module.mk: Add new function to the list.
* system.txi: Add verLessThan doc string to the manual.
* NEWS: Add verLessThan to the list of new functions.

diff -r 884fdd6c9210 -r 0f187a956d47 NEWS
--- a/NEWS	Tue Jan 22 23:46:33 2019 -0800
+++ b/NEWS	Mon Jan 21 17:52:20 2019 -0500
@@ -4,6 +4,7 @@
  ** New functions added in 6.0:
 
       lightangle
+      verLessThan
 
  ** Deprecated functions.
 
diff -r 884fdd6c9210 -r 0f187a956d47 doc/interpreter/system.txi
--- a/doc/interpreter/system.txi	Tue Jan 22 23:46:33 2019 -0800
+++ b/doc/interpreter/system.txi	Mon Jan 21 17:52:20 2019 -0500
@@ -533,6 +533,8 @@
 
 @DOCSTRING(compare_versions)
 
+@DOCSTRING(verLessThan)
+
 @DOCSTRING(license)
 
 @DOCSTRING(getrusage)
diff -r 884fdd6c9210 -r 0f187a956d47 scripts/miscellaneous/module.mk
--- a/scripts/miscellaneous/module.mk	Tue Jan 22 23:46:33 2019 -0800
+++ b/scripts/miscellaneous/module.mk	Mon Jan 21 17:52:20 2019 -0500
@@ -78,6 +78,7 @@
   %reldir%/unzip.m \
   %reldir%/validateattributes.m \
   %reldir%/ver.m \
+  %reldir%/verLessThan.m \
   %reldir%/version.m \
   %reldir%/what.m \
   %reldir%/zip.m
diff -r 884fdd6c9210 -r 0f187a956d47 scripts/miscellaneous/verLessThan.m
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/miscellaneous/verLessThan.m	Mon Jan 21 17:52:20 2019 -0500
@@ -0,0 +1,67 @@
+## Copyright (C) 2019 Andrew Janke
+##
+## 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
+## <https://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {} {@var{out} =} verLessThan (@var{package}, @var{version})
+## True if the installed version of the package is less than @var{version}.
+##
+## @var{package} is the name of the package to check the version of. Use
+## @code{"Octave"} as the @var{package} to check the version of Octave itself.
+##
+## @var{version} is the version to compare it to. A version is a string in the
+## format accepted by @ref{XREFcompare_versions, ,compare_versions function}:
+## an arbitrarily long string made of numeric and period characters possibly
+## followed by an arbitrary string (e.g., @code{"1.2.3"}, @code{"0.3"},
+## @code{"0.1.2+"}, or @code{"1.2.3.4-test1"}).
+##
+## @example
+## @group
+## tf = verLessThan ("Octave", "5.0.0")
+## tf = verLessThan ("io", "2.4.12")
+##
+## if (! verLessThan ("Octave", "5.0.0"))
+##   ## ... use new Octave 5.0 features ...
+## endif
+## @end group
+## @end example
+##
+## @seealso{compare_versions, version, ver, pkg}
+## @end deftypefn
+
+function out = verLessThan(package, version)
+
+  if (! ischar (package) || size (package, 1) > 1)
+    error ("verLessThan: package must be a char vector");
+  endif
+
+  v = ver ();
+  idx = find (strcmpi (package, {v.Name}));
+  if (isempty (idx))
+    error ("verLessThan: Package ""%s"" is not installed.", package);
+  endif
+
+  out = compare_versions (v(idx).Version, version, "<");
+
+endfunction
+
+%!assert (! verLessThan ("Octave", "3.0.0"))
+%!assert (verLessThan ("Octave", "99.9.9"))
+%!error <Package "no-such-package" is not installed.>
+%! verLessThan ("no-such-package", "1.1.1")
+%!error <compare_versions: version numbers V1 and V2 must be strings>
+%! verLessThan ("Octave", 4.1)