simple translator: Replaced 'GF Robust Parser' with 'GF Wide Coverage Translation'

The interface to the wide coverage translation is in js/gftranslate.js
and it assumes that the grammar is installed on the cloud server
as /robust/Translate8.pgf.

The list of supported languages is hardwired in gftranslate.js, since
there is no support for obtaining this info from the C run-time system
at the moment.

src/www/js/gftranslate.js

@@ -0,0 +1,34 @@
+
+/* --- GF wide coverage translation interface ------------------------------- */
+
+var gftranslate = {}
+
+gftranslate.jsonurl="/robust/Translate8.pgf"
+gftranslate.grammar="Translate" // the name of the grammar
+gftranslate.languages="Bul Chi Eng Fin Fre Ger Hin Swe".split(" ")
+                    // hardwired for now
+
+gftranslate.call=function(querystring,cont) {
+    http_get_json(gftranslate.jsonurl+querystring,cont)
+}
+
+// Translate a sentence to the given target language
+gftranslate.translate=function(source,from,to,cont) {
+    var encsrc=encodeURIComponent(source)
+    var g=gftranslate.grammar
+    function extract(result) {
+	cont(result[0].translations[0].linearizations[0].text)
+    }
+    if(encsrc.length<200) // match limit in runtime/c/utils/pgf-server.c
+	gftranslate.call("?command=c-translate&input="+encsrc
+		      +"&from="+g+from+"&to="+g+to+"&limit=1",extract)
+    else cont("[GF robust parser: sentence too long]")
+}
+
+// Get functions to test which source and target langauges are supported
+gftranslate.get_support=function(cont) {
+    if(!gftranslate.targets) gftranslate.targets=toSet(gftranslate.languages)
+    function ssupport(code) { return gftranslate.targets[code] }
+    function tsupport(code) { return gftranslate.targets[code] }
+    cont(ssupport,tsupport)
+}