update packages

[CreaPhase.git] / octave_packages / m / help / print_usage.m

diff --git a/octave_packages/m/help/print_usage.m b/octave_packages/m/help/print_usage.m
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+## Copyright (C) 2009-2012 S�ren Hauberg
+##
+## 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} {} print_usage ()
+## @deftypefnx {Function File} {} print_usage (@var{name})
+## Print the usage message for a function.  When called with no input arguments
+## the @code{print_usage} function displays the usage message of the currently
+## executing function.
+## @seealso{help}
+## @end deftypefn
+
+function print_usage (name)
+  x = dbstack ();
+  ## Handle input
+  if (nargin == 0)
+    ## Determine the name of the calling function
+    if (numel (x) > 1)
+      name = x (2).name;
+    else
+      error ("print_usage: invalid function\n");
+    endif
+    fullpath = evalin ("caller", "mfilename (""fullpath"")");
+    if (strcmp (fullpath(end-length(name)+1:end), name))
+      fullname = [fullpath, ".m"];
+    endif
+  elseif (!ischar (name))
+    error ("print_usage: input argument must be a string");
+  else
+    fullname = name;
+  endif
+
+  ## Determine if we're called from top level.
+  at_toplev = length (x) < 2 || (length (x) == 2 && strcmp (x(2).name, name));
+
+  ## Do the actual work
+  [text, format] = get_help_text (fullname);
+  max_len = 80;
+  switch (lower (format))
+    case "plain text"
+      [usage_string, status] = get_usage_plain_text (text, max_len);
+    case "texinfo"
+      [usage_string, status] = get_usage_texinfo (text, max_len);
+    case "html"
+      [usage_string, status] = get_usage_html (text, max_len);
+    case "not documented"
+      error ("print_usage: `%s' is not documented\n", name);
+    case "not found"
+      error ("print_usage: `%s' not found\n", name);
+    otherwise
+      error ("print_usage: internal error: unsupported help text format: '%s'\n", format);
+  endswitch
+
+  ## Raise the final error
+  if (status != 0)
+    warning ("print_usage: Texinfo formatting filter exited abnormally");
+    warning ("print_usage: raw Texinfo source of help text follows...\n");
+  endif
+
+  if (at_toplev)
+    error ("Invalid call to %s.  Correct usage is:\n\n%s\n%s",
+           name, usage_string, __additional_help_message__ ());
+  else
+    msg = sprintf ("Invalid call to %s.  Correct usage is:\n\n%s",
+                   name, usage_string);
+    ## Ensure that the error doesn't end up with a newline, as that disables
+    ## backtraces.
+    if (msg(end) == "\n")
+      msg(end) = " ";
+    endif
+
+    error (msg);
+  endif
+
+endfunction
+
+function [retval, status] = get_usage_plain_text (help_text, max_len)
+  ## Extract first line by searching for a double line-end.
+  line_end_idx = strfind (help_text, "\n\n");
+  retval = help_text (1:min ([line_end_idx , max_len, length(help_text)]));
+  status = 0;
+endfunction
+
+function [retval, status] = get_usage_texinfo (help_text, max_len)
+  ## Lines ending with "@\n" are continuation lines, so they should be
+  ## concatenated with the following line.
+  help_text = strrep (help_text, "@\n", " ");
+
+  ## Find, and keep, lines that start with @def or @end def. This should include things
+  ## such as @deftypefn, @deftypefnx, @defvar, etc. and their corresponding @end's
+  def_idx = strfind (help_text, "@def");
+  if (!isempty (def_idx))
+    buffer = "";
+    endl_idx = find (help_text == "\n");
+    for k = 1:length (def_idx)
+      endl = endl_idx (find (endl_idx > def_idx (k), 1));
+      if (isempty (endl))
+        buffer = strcat (buffer, help_text (def_idx (k):end), "\n");
+      else
+        buffer = strcat (buffer, help_text (def_idx (k):endl));
+      endif
+    endfor
+
+    end_def_idx = strfind (help_text, "@end def");
+    if (!isempty (end_def_idx))
+      buffer = strcat (buffer, help_text (end_def_idx:end));
+    endif
+  else
+    [retval, status] = get_usage_plain_text (help_text, max_len);
+  endif
+
+  ## Run makeinfo to generate plain text
+  [retval, status] = __makeinfo__ (buffer, "plain text");
+endfunction
+
+function [retval, status] = get_usage_html (help_text, max_len)
+  ## Strip tags
+  [help_text, status] = strip_html_tags (help_text);
+
+  ## Extract first line with plain text method.
+  retval = get_usage_plain_text (help_text, max_len);
+endfunction
+
+
+## Stop reporting function as missing tests.  No good tests possible.
+%!assert (1)
+