CSE 428: Quizzes

Please write your Name and Student ID,at the top of the page.
By default, this quiz will be returned in Section 1 (afternoon section).

[Pts 2]
Consider the definition
```
   fun f [] = 0
     | f (x::L) =  (f L) - x + 1;
```
What is the result of f [0,1,2]; ? (only one answer, please)
- error
- 0
- 1
- ~3 (remember that "~" in ML is the unary minus sign)
[Pts 2] What is the effect of the following sequence of declarations? (only one answer, please)
```
   val (x,y) = ([1],[[1]]);
   val (x,y) = (y,x);
```
- The truth value false, because [1] is not equal to [[1]]
- Error, because the keyword "val" expects a variable afterwards
- Error, because [1] and [[1]] have different types
- x is associated to the value [[1]] and y is associated to the value [1]
[Pts 2] What is the result of the expression tl ["Luigi","Mario","Piero"]; (only one answer, please. Remember that tl represents the function "tail of a list".)
- ["Piero"]
- ["Mario","Piero"]
- error
- the pointer to the last element of the list (i.e. to the element which contains "Piero")
[Pts 4] Consider the following definition:
```
   fun papp (x::nil) L = L
     | papp (x::K) L = x::(papp K L);
```
For each of the following expressions, say what is the result, or say whether it's an error.
- papp [] ["Mario"]; error
- papp ["Mario"] [2]; error
- papp ["Mario"] ["Luigi"]; ["Mario","Luigi"]
- papp ["Mario"] []; ["Mario"]