Babel in ConTeXt(LuaTeX)

Question

I am interesting in ConTeXt(LuaTeX) but my biggest problem is that I could not translate a simple program from LuaLaTeX, that uses babel, to a corresponding ConTeXt(LuaTeX) one. The code is the following:

\documentclass[12pt]{article}
\usepackage[polutonikogreek,english]{babel}
\usepackage{luatex}
\usepackage{fontspec}
\setmainfont[ExternalLocation]{TheanoDidot-Regular}
\renewcommand*{\greektext}{}

\begin{document}

\selectlanguage{greek}
ἡ ῥητορική  ἐστιν  ἀντίστροφος  τῇ διαλεκτικῇ:
ἀμφότεραι  γὰρ  περὶ 
τοιούτων  τινῶν  εἰσιν  ἃ κοινὰ  τρόπον  τινὰ  ἁπάντων 
ἐστὶ  γνωρίζειν 
  καὶ  οὐδεμιᾶς  ἐπιστήμης  ἀφωρισμένης: διὸ  καὶ 
πάντες  τρόπον  τινὰ 
  μετέχουσιν  ἀμφοῖν: πάντες  γὰρ  μέχρι τινὸς καὶ
ἐξετάζειν καὶ ὑπέχειν 
λόγον καὶ ἀπολογεῖσθαι καὶ κατηγορεῖν ἐγχειροῦσιν.

\selectlanguage{english}
Typing in Greek in \LaTeX{} is fun! 
\end{document}

Answer 1

Maybe this is what you want:

\usemodule[simplefonts]
\setmainfont[TheanoDidot-Regular]                 
\setupbodyfont[12pt]
\mainlanguage[greek]
\starttext
ἡ ῥητορική  ἐστιν  ἀντίστροφος  τῇ διαλεκτικῇ:
ἀμφότεραι  γὰρ  περὶ 
τοιούτων  τινῶν  εἰσιν  ἃ κοινὰ  τρόπον  τινὰ  ἁπάντων 
ἐστὶ  γνωρίζειν 
  καὶ  οὐδεμιᾶς  ἐπιστήμης  ἀφωρισμένης: διὸ  καὶ 
πάντες  τρόπον  τινὰ 
  μετέχουσιν  ἀμφοῖν: πάντες  γὰρ  μέχρι τινὸς καὶ
ἐξετάζειν καὶ ὑπέχειν 
λόγον καὶ ἀπολογεῖσθαι καὶ κατηγορεῖν ἐγχειροῦσιν.
\language[en]
Typing in Greek in \ConTeXt{} is easy! 
\stoptext

1. The font is from http://www.thessalonica.org.ru/en/fonts-download.html .
2. Assuming a standalone (was minimals) installation, put it under texmf-project/font; then run context --generate and mtxrun --script fonts --reload.
3. Check the font with mtxrun --script fonts --list theano --all

The log says

fonts           > otf prepare > unsupported coverage contextpos for 'RQD ' Greek Caps after Accents Positioning-1

This means that there are some problems. I will send the example to the context ml.