Renamed Bool to ASTBool
Changed back to Bool and added decimal class
Bool, decimal and number clases
Added number test and wrote dec and int visit functions
Added to string
Made value in values private final
Fixed setting lhs and rhs private final and still printing them
Wrote small dec test and tested
Added unary expression, neq expression and adjusted braced expr and antlrvisitor. Started on custom visitors
Visit neg expression in antlrvisitor
Added abstract QLVisitor class, wrote required functions in interface and extended undefinedCheck
Changed variables in upper level abstract tree nodes to final private and edited antlr4visitor appropriately
Changed vars in structures back to QLTree, as this is, unfortunately, necessary
Made sure most upper level ast nodes accept visitors
Renamed visitor interface
Wrote visiting stuff for form and question
renamed QLVisitor to QLErrorVisitor
Finished abstract error visitor
Finally actually added iqlVisitor and QLErrorVisitor after renaming; added extra check on visitChild
Wrote tests in own function, added visiting identifier in antlr visitor, changed some little stuff in QLErrorVisitor and implemented undefinedcheck