Unfortunately no one provided an answer to my question :)
I had to reverse engineering Jison Lexer code to find out the right syntax. As I suppose it may help others, here after the answer :)
Jison's lexical conditions work fine under JSON syntax, but they should be predeclared in an array named "startConditions" as in following example.
grammar = {
"lex": {
"startConditions" : { "INITIAL":"// Default initial Jison/Lex context"
,"MOD_EXT": "// extenstions context "
,"MOD_RTE": "// routes context"
},
"rules" : [['[\\n\\s]+' , "/* skip whitespace & new lines */"]
// extensions blocs
,[['INITIAL'], '<extensions>' , "this.begin('MOD_EXT');"]
,[['MOD_EXT'], '<\\/extensions>' , "this.popState();"]
,[['MOD_EXT'], '[<>\\/\\-\\s\\n]', "/* ignore */"]
,[['MOD_EXT'], '[0-z]+' , "/* ignore */"]
Etc...
In order to make everyone life easier, here after a simple working example.
// Sample JISON start conditions with Jason syntax
var jison = require("jison").Parser;
grammar = {
"lex": {
"macros": { // few usefull macro
"slash": "\\/",
"space": "\\s+",
"quot" : "\\\'",
"dquot": "\\\"",
"dot" : "\\.",
"digit": "[0-9]",
"int" : "-?([0-9]+)",
"float": "-?([0-9]*\\.[0-9]+)",
"hexa" : "([0-9]|(a-h)|(A-H])+"
},
"startConditions" : { "INITIAL":"// Default initial Jison/Lex context"
,"MOD_EXT": "// extenstions context "
,"MOD_RTE": "// routes context"
},
"rules" : [['[\\n\\s]+' , "/* skip whitespace & new lines */"]
// extensions blocs
,[['INITIAL'], '<extensions>' , "this.begin('MOD_EXT');"]
,[['MOD_EXT'], '<\\/extensions>' , "this.popState();"]
,[['MOD_EXT'], '[<>\\/\\-\\s\\n]', "/* ignore */"]
,[['MOD_EXT'], '[0-z]+' , "/* ignore */"]
// routes points blocs
,[['INITIAL'],'<rtept' , "this.begin('MOD_RTE'); return 'RTE_BEG';"]
,[['MOD_RTE'], '<\\/rtept>' , "this.popState(); return 'RTE_END';"]
,[['MOD_RTE'], 'lat=' , "return 'LAT';"]
,[['MOD_RTE'], 'lon=' , "return 'LON';"]
,[['MOD_RTE'], '{float}' , "return 'CARD';"]
,[['MOD_RTE'], '<name>' , "return 'NAME_BEG';"]
,[['MOD_RTE'], '<\\/name>' , "return 'NAME_END';"]
,[['MOD_RTE'], '<time>' , "return 'TIME_BEG';"]
,[['MOD_RTE'], '<\\/time>' , "return 'TIME_END';"]
,[['MOD_RTE'], '<sym>' , "return 'SYM_BEG';"]
,[['MOD_RTE'], '<\\/sym>' , "return 'SYM_END';"]
,[['MOD_RTE'], '<type>' , "return 'TYPE_BEG';"]
,[['MOD_RTE'], '<\\/type>' , "return 'TYPE_END';"]
,[['MOD_RTE'], '<extensions>' , "this.begin('MOD_EXT');"]
,[['MOD_RTE'], '([0-z]|[-+])+\\b' , "return 'TEXT';"]
,[['MOD_RTE'], '[>{quot}{dquot}{space}]' , "// ignore"]
// end of parsing buffer
,['$' , "return 'EOL';"]
]
}, // end Lex rules
"bnf": { // WARNING: only one space in between TOKEN ex: "STOP EOF"
'data': [
["EOL" , "return ('EMPTY');"]
,["ROUTEPOINTS EOL", "return (this.route);"]
]
// handle multiple waypoints
// A routepoint should at least have a LAT+LONG+NAME
,'ROUTEPOINTS' : [ // store all waypoint in an array
["ROUTEPOINT", "console.log('Parsing First Waypts=%j',this.waypts);this.route=[]; this.route.push(this.waypts);"]
,["ROUTEPOINTS ROUTEPOINT", "console.log('Parsing Next Waypts=%j',this.waypts);;this.route.push(this.waypts);"]
]
// A routepoint should at least have a LAT+LONG+NAME
,'ROUTEPOINT' : [ // <rtept lat='47.542780648' lon='-2.896743643'>...
["RTE_BEG LATITUDE LONGITUDE DATE NAME SYM TYPE RTE_END", "this.waypts={lat:$2,lon:$3,name:$5,date:$4};"]
,["RTE_BEG LATITUDE LONGITUDE DATE NAME RTE_END", "this.waypts={lat:$2,lon:$3,name:$5,date:$4};"]
,["RTE_BEG LATITUDE LONGITUDE NAME RTE_END", "this.waypts={lat:$2,lon:$3,name:$4,date:'unknow'};"]
]
// lat='47.542780648'
,'LATITUDE' : [["LAT CARD", "$$=$2;"]]
// lon='-2.896743643'
, 'LONGITUDE' : [["LON CARD", "$$=$2;"]]
//<time>2014-09-16T21:55:19Z</time>\
, 'DATE' : [["TIME_BEG TEXT TIME_END", "$$=$2;"]]
// <name>001</name>\
, 'NAME' : [["NAME_BEG TEXT NAME_END", "$$=$2;"]]
// <sym>001</name>\
, 'SYM' : [["SYM_BEG TEXT SYM_END", "//ignore"]]
// <name>001</name>\
, 'TYPE' : [["TYPE_BEG TEXT TYPE_END", "//ignore"]]
}};
parser = new jison(grammar);
test= "\
<extensions>\
<opencpn:start></opencpn:start><opencpn:end></opencpn:end>\
<opencpn:viz>1</opencpn:viz>\
<opencpn:guid>714d1d6e-78be-46a0-af6e-2f3d0c505f6d</opencpn:guid>\
</extensions>\
<rtept lat='47.542780648' lon='-2.896743643'>\
<time>2014-09-16T21:55:19Z</time>\
<name>001</name>\
<sym>diamond</sym>\
<type>WPT</type>\
<extensions>\
<opencpn:guid>408c309c-6a8c-411d-815b-0c0054646d45</opencpn:guid>\
<opencpn:viz>1</opencpn:viz>\
<opencpn:viz_name>0</opencpn:viz_name>\
<opencpn:auto_name>1</opencpn:auto_name>\
</extensions>\
</rtept>\
<rtept lat='44.542780648' lon='-4.896743643'>\
<time>2014-08-16T21:55:19Z</time>\
<name>002</name>\
</rtept>\
<rtept lat='43.542780648' lon='-5.896743643'>\
<name>003</name>\
</rtept>\
<rtept lat='48.542780648' lon='-3.896743643'>\
<time>2014-10-16T21:55:19Z</time>\
<name>004</name>\
<sym>diamond</sym>\
<type>WPT</type>\
<extensions>\
<opencpn:guid>408c309c-6a8c-411d-815b-0c0054646d45</opencpn:guid>\
<opencpn:viz>1</opencpn:viz>\
<opencpn:viz_name>0</opencpn:viz_name>\
<opencpn:auto_name>1</opencpn:auto_name>\
</extensions>\
</rtept>";
route=parser.parse (test);
console.log ("\n\nMy GPX route's waypoints");
for (var waypts in route) {
console.log (" -- name: %s Lon: %s Lat:%s Date:%s", route [waypts].name, route [waypts].lat, route [waypts].lon, route [waypts].date);
};
console.log ("done");