Lexer rules

Lexer will generate a collection of meaningful tokens using a mere charater stream.

Following statement represents a single line comment.

COMMENT : '--' (~('\r' '\n'))* NLfrag { $channel = HIDDEN; } ;

fragment NLfrag : ('\r' '\n'? '\n') ;  

• COMMENT - An individual token
•    '--' - Starting point of the single line comment - a single Match() statement
•    (~('\r' '\n'))* - Comment can be followed by zero of more times of new line characters, tab characters etc. - A loop
•    $channel = HIDDEN - Do not show this token to parser! -
• NLfrag - Calls another token - recursively calls mNLfrag() function
• '\n'? - Newline is optional