TOKENS 
ident = letter{letter|digit}.
number = digit{digit}.
string = '"' {noquote1| "'" } '"' | "'" {noquote2|'"' }"'" .
Special = special.
float = digit{["_"]digit}("."digit{["_"]digit}[("E"|"e")["+"|"-"]digit{["_"]digit}]|("E"|"e")["+"|"-"]digit{["_"]digit}).
