Given the following grammar, which is a string that could be generated?

a -> b | c ;
b -> "matt" d ;
c -> "damian" e ;
d -> "makes me sad" |  "broke my skateboard" | "ate my lunch" ;
e -> "is tops" | "is my favourite" ;

Which of the following is a good reason for using the visitor pattern for traversing AST nodes?

When generating the AST classes for our Lox interpreters, what is the purpose of writing a "tool" (e.g., GenerateAst)?

In the following grammar, which symbols are "terminals"

e -> t | f ;
t -> "foo" | "bar" ;
f -> "foo()" | "bar()" ;

Terminals are represented with a quoted string in the metasyntax. Which of the concepts we've seen so far represent terminals in our interpreter?

Which lox expression corresponds to the following tree? .

Which of the following are optimisations a compiler/interpreter might do?  Note, there could be more than one correct answer.

Imagine the following diagram of programming language implementation options is sound and complete. We want to create a compiler/interpreter to convert our "source" language into one of out target languages (x86 or ARM).

How many different possible implementations are there? (Hint, this is a COMP2010 question)

Which of these characteristics would make a language implementation certainly a compiler: