a newe private function to get method's texinfo from the classdef fil…

…e as a workaround of the behavior of 'get_help_text', see bug #65220

inst/private/get_methods_texinfo.m

@@ -0,0 +1,76 @@
+## Copyright (C) 2024 Andreas Bertsatos <abertsatos@biol.uoa.gr>
+##
+## This file is part of the statistics package for GNU Octave.
+##
+## This program 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.
+##
+## This program 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
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {pkg-octave-doc} {@var{text} =} get_methods_help_text (@var{class}, @var{method})
+##
+## Private function to parse a method texinfo from a classdef file.
+##
+## @end deftypefn
+
+function text = get_methods_texinfo (class, method);
+
+  ## Get the path to the classdef
+  pathname = which (class);
+
+  ## Read source file
+  fid = fopen (pathname);
+  txt = fscanf (fid, "%c", Inf);
+  fclose (fid);
+
+  ## Find texinfo blocks
+  txt_beg = strfind (txt, "## @deftypefn ");
+  txt_end = strfind (txt, "## @end deftypefn");
+
+  if (numel (txt_beg) != numel (txt_end))
+    warning ("get_methods_texinfo: texinfo blocks not properly terminated.");
+    text = "";
+    return;
+  endif
+
+  ## Search texinfo block for given method
+  method_found = false;
+  for i = 1:numel (txt_beg)
+    textblock = txt([txt_beg(i):txt_end(i)+16]);
+    firstline = textblock([1:strfind(textblock,"\n")(1)-1]);
+    if (! isempty (strfind (firstline, method)))
+      helptext = textblock;
+      method_found = true;
+    endif
+  endfor
+
+  if (method_found)
+    ## Remove '##' and leading spaces from each line
+    nl_idx = strfind (helptext, "\n");
+    begidx = 1;
+    endidx = length (helptext);
+    if (nl_idx(end) < endidx)
+      nl_idx = [nl_idx, endidx];
+    endif
+    text = "\n";
+    for i = 1:numel (nl_idx)
+      txt_line = helptext([begidx:nl_idx(i)]);
+      txt_line(strfind (txt_line, "#")) = [];
+      txt_line = strtrim (txt_line);
+      begidx = nl_idx(i) + 1;
+      text = sprintf ("%s%s\n", text, txt_line);
+    endfor
+  else
+    text = "";
+  endif
+
+endfunction