On Fri, Jul 19, 2019 at 02:29:52PM +0200, pelzflorian (Florian Pelz) wrote:
> I will try writing a custom xgettext that combines
> nested·s-expressions·that are marked for translation with G_
> to·a·single·msgstr that gets written to the·PO·file.  This combined
> string will not be part of the source code but will be generated from
> a nested sexp.  The PO file containing the combined strings can then
> be translated as usual.  For reading the translation, the combined
> msgstr will be constructed again by the marking procedure G_ and
> looked up by reading from an MO file.
> 

I have implemented a working translation tool.  Sexp-xgettext
generates from an SHTML or other Scheme file with marked s-expressions
a POT file which can be translated and turned into an MO file from
which the code generates a localized HTML builder.  The advantage is
that existing SHTML will just have to be marked with G_ and no format
string has to be written, although sometimes the SHTML should be
adapted to produce a less complicated message in the POT file.  Find
attached an example of a marked Scheme file home.scm generating
guix-website.pot, which after manual translation generates the
attached guix.de_DE.html.

Marking a string for translation behaves like normal gettext.  Marking
a parenthesized expression (i.e. a list or procedure call) extracts
each string from the parenthesized expression.  If a symbol, keyword
or other parenthesized expression occurs between the strings, it is
extracted as an XML element.  Expressions before or after all strings
are not extracted.  If strings from a parenthesized sub-expression
shall be extracted too, the sub-expression must again be marked with
G_ unless it is the only sub-expression or it follows a quote,
unquote, quasiquote or unquote-splicing.  The order of XML elements
can be changed in the translation to produce a different ordering
inside a parenthesized expression.  If a string shall not be extracted
from a marked expression, it must be wrapped, for example by a call to
the identity procedure.

But there are still some bugs like missing line numbers and
non-working pgettext and the code is not clear enough yet.  I will
send a patch series tomorrow after I fixed these issues (even though
the documentation won’t be near as good as sirgazil’s format strings).

Regards,
Florian