COMPILER Index $CN
/**
 * Ronald Munodawafa
 * 15M1595
 * Practical 4
 * Task 1
 */


CHARACTERS
    digit       =   "1234567890" .
    lower       =   "qwertyuiopasdfghjklzxcvbnm" .
    upper       =   "QWERTYUIOPASDFGHJKLZXCVBNM" .
    letter      =   upper + lower .

TOKENS
    word        =   letter { letter | "++" | "-" digit } .
    number      =   digit { digit } .

IGNORE CHR(0) .. CHR(9) + CHR(11) .. CHR(31)

PRODUCTIONS
    Index       =   Entry [ Index ] EOF .
    Entry       =   Label Reference ( "\n" | "\r\n" ) .
    Reference   =   See | Pages .
    Pages       =   Page [ "," ( Appendix | Pages ) ] .
    See         =   "--" "see" Label .
    Appendix    =   "Appendix" number .
    Page        =   number [ "-" number ] .
    Label       =   ( word | "(" Label ")" ) [ [ "," ] Label ] .
END Index .