feat(package): hemar: antlr grammar, but still does not work

package/hemar/grammar/antlr/HemarLexer.g4

@@ -0,0 +1,49 @@
+lexer grammar HemarLexer;
+
+// ---------- default mode: plain text ----------
+
+// Everything that is not the start of "{[" is TEXT
+TEXT
+  : ( ~'{' | '{' ~'[' )+
+  ;
+
+// When we see "{[", emit LeftBrace and enter TAG mode
+LeftBrace
+  : '{[' -> pushMode(TAG)
+  ;
+
+// skip whitespace in plain text if you want
+SKIP_WS
+  : [ \t\r\n]+ -> skip
+  ;
+
+// ---------- TAG mode: inside {[ ... ]} ----------
+
+mode TAG;
+
+fragment WS: [ \t\r\n] ;
+
+For : 'for';
+In  : 'in';
+End : 'end';
+
+// identifier inside tag
+Path
+  : String
+  | String '.' Path
+  ;
+
+String
+  : ( ~[.\] \t\r\n] | ']' ~[}. \t\r\n] )+
+  | '"' ( ~'"' | '\\' '"'  )+ '"'
+  ;
+
+// closing "]}": emit RightBrace and go back to default mode
+RightBrace
+  : ']}' -> popMode
+  ;
+
+// skip whitespace inside tag
+SKIP_TAG_WS
+  : WS+ -> skip
+  ;