Re: [Docutils-users] include :code: eats tabs

[Guenter M. <mi...@us...>]

Dear Chris,

On 2018-08-28, Chris Pickel wrote:

> [-- Type: text/plain, Encoding: quoted-printable --]

> I tried using the “include” directive with :code: and :tab-width: -1.
> For some reason, all of the tabs disappeared.
...
> If I remove :tab-width: -1, Pygments no longer detects the tabbed
> lines as errors, but the quoted output still can’t be copy-pasted, as
> hard tabs are required in Makefiles.

Thank you for reporting the problem. Indeed, negative values for the
"tab-width" option work only with files included as "literal".
This restriction is currently not documented in 
http://docutils.sourceforge.net/docs/ref/rst/directives.html#including-an-external-document-fragment

Literal tabs can be preserved in "code" inclusions, too ---
please try the following patch for the directive code:

diff --git a/trunk/docutils/docutils/parsers/rst/directives/misc.py b/trunk/docutils/docutils/parsers/rst/directives/misc.py
index 638974230..fab450a6d 100644
--- a/trunk/docutils/docutils/parsers/rst/directives/misc.py
+++ b/trunk/docutils/docutils/parsers/rst/directives/misc.py
@@ -144,6 +144,9 @@ class Include(Directive):
             return [literal_block]
         if 'code' in self.options:
             self.options['source'] = path
+            # Convert tabs to spaces, if `tab_width` is negative.
+            if tab_width < 0:
+                include_lines = rawtext.splitlines()
             codeblock = CodeBlock(self.name,
                                   [self.options.pop('code')], # arguments
                                   self.options,


LaTeX ignores leading whitespace, so the following is a workaround to
get a visible representation of literal tabs in LaTeX-generated PDF (there
is no easy way to achieve preservation of TAB characters in drag and drop
from the PDF, though).

diff --git a/trunk/docutils/docutils/writers/latex2e/__init__.py b/trunk/docutils/docutils/writers/latex2e/__init__.py
index 0463e3504..fafab2c34 100644
--- a/trunk/docutils/docutils/writers/latex2e/__init__.py
+++ b/trunk/docutils/docutils/writers/latex2e/__init__.py
@@ -1516,6 +1516,10 @@ class LaTeXTranslator(nodes.NodeVisitor):
                 table[ord('>')] = ur'\textgreater{}'
         if self.insert_non_breaking_blanks:
             table[ord(' ')] = ur'~'
+            # tab chars may occur in included files (literal or code)
+            # quick-and-dirty replacement with spaces
+            # (for better results use `--literal-block-env=lstlisting`)
+            table[ord('\t')] = u'~' * self.settings.tab_width
         # Unicode replacements for 8-bit tex engines (not required with XeTeX/LuaTeX):
         if not self.is_xetex:
             if not self.latex_encoding.startswith('utf8'):

sincerely,

Günter