week3

Question 1

pbr vs pbn (if expression in param)

Answer 1

pbr evaluates expression at function call, pbn evaluates expression in body (bc expression is copied into function body)

Question 2

how to implement algol copy rule

Answer 2

pass in closure

Question 3

java value of obj is =

Answer 3

address

Question 4

functional lang

Answer 4

• no notion of state
• programs are collections of function definitions and uses of function call
• func are “first class” obj - can pass as params, return as vals, include in data struct
• recursions only form of rep
• binding but no assignment statement

Question 5

tail recursion

Answer 5

recursive call is last step

Question 6

side effects

Answer 6

any change to state of system that influences dependent values