PLQ #2Done on:   Tuesday, January 24th

Question 1 @ 2023-01-24 18:55

What’s the problem with this BNF:

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• 0
  There is no problem.
• 1
  It’s ambiguous.
• 2
  It has an infinte loop so it’s undecidable.
• 3
  It repeats a sub-pattern, so could be written in a better way.
• 4
  It does not enforce normalized sets of pages.

Question 2 @ 2023-01-24 19:00

What is the reason we’re using BNFs to specify our language(s)?

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• 1
  They’re a common simple way of specifying grammars.
• 2
  They’re easier to implement compilers for.
• 3
  They enforce compositional evaluation, so they simplify the language.
• 4
  They turned out to be useful representations, as seen by the history of S-expressions in Lisp.
• 5
  No real reason.

Question 3 @ 2023-01-24 19:03

The AE BNF is:

Is this for a language that evaluates expressions left-to-right or right-to-left?

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• 1
  It is LtR
• 2
  It is RtL
• 3
  It’s non-deterministic
• 4
  Order is unrelated
• 5
  Depends on the calling compiler