Am 26.12.2013 um 23:18 schrieb Rudolf Bahr <quasi@quasi.de>:

On Thu, Dec 26, 2013 at 08:49:30PM +0100, Wolfgang Schuster wrote:

Have you tried the unifraktur fonts, as you can see on the website the font has features to change
the umlauts and also to replace the normal s with the long s.

\definefontfamily[mainface][rm][Unifraktur Maguntia]

\setupbodyfont[mainface]

\definefontfeature [longs]     [cv11=yes]
\definefontfeature [diaeresis] [cv15=yes]

\mainlanguage[de]

\starttext

\input knuth

schönstes – {\feature[+][longs]schönstes}

ſchön Üben – {\feature[+][diaeresis]ſchön Üben}

\quotation{Quoted text}

\stoptext

Wolfgang


This is the answer of my context (version: 2013.05.28 00:36):

l.2 \definefontfamily
                  [mainface][rm][Unifraktur Maguntia]
? h
The control sequence at the end of the top line
of your error message was never \def'ed. If you have …

Replace the \definefontfamily line with

  \definetypeface [mainface] [rm] [specserif] [Unifraktur Maguntia] [default]

because the new font command was added last autumn and your TeXLive installation
uses a older context version (not sure if the \feature command exists there).

I don't know, whether there apply in English texts the same rules as in German ones with respect 
to Fraktur or similar fonts.
The written Knuth text (in the .pdf-file) would contain some right "s" at end of words and syllabs 
as in "Thus", "components", "activities" or the third "s" in successfull, but the rest of all the 
other "s" would be wrong. 

What do you expect from a text with doesn’t contain any long s in the input.

Maybe your expecting from context to make the right choice for the s but there
are cases where you won’t get the correct output and manual correction
is necessary.

Wolfgang