Question 1 @ 2021-10-26 18:32
In the Brang language from homework #6, what would this evaluate to?
(run "{with {fun {fun {fun} fun}}
{with {foo {fun {fun} {+ fun 1}}}
{call fun foo 123}}}")
- An error saying that
foo is unbound
- An error about getting a function when a number is expected
- An error because we shadow
fun so the code is broken
- An error due to the preprocessor auto-currying
- 123
- 124
Question 2 @ 2021-10-26 18:35
With encoded Church numerals in Schlac, what arithmetic operator does
the following represent?
(lambda (m n) (lambda (f x) (m f (n f x))))
- +
- -
- *
- /
- ^
- It does not represent any arithmetic operator
Question 3 @ 2021-10-26 18:38
Why do we need “protection” when writing our Y combinator?
- Without it we get a free identifier instead of a recursive
reference.
- Avoids the problem of laziness.
- Infinite loops due to eager evaluation.
- Enables substitution when using lexical scope.
- The Y combinator does not need protection.
- Avoids losing recursive references when switching from dynamic
to lexical scope.
Question 4 @ 2021-10-26 18:40
Of the following definitions that we used in Schlac, which ones are
the same as the identity function? (Note: multiple choice)