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--- fp:lab06 [2022/04/05 13:34]
pdmatei
+++ fp:lab06 [2022/04/08 12:45] (current)
pdmatei
@@ Line 41: / Line 41: @@
     xs.foldLeft(op(acc,x))(op)
   }
-}
 </code>
+Add the following methods in the trait ''FList'' and implement them. **Some methods can be directly implemented in the trait, using ''map'', ''foldRight'', ''foldLeft'' or other functions.**
+  * Can you figure which ones are best implemented in the trait and which in the case classes?
+**6.1.** ''indexOf'' determines the position of a value in the list (starting with 0)
+<code scala>
+def indexOf(e: A): Int
+</code>
+**6.2.** ''update'' creates a new list where the given position is modified with a new value:
+<code scala>
+//Cons(1,Cons(2,Cons(3,FNil()))).update(9,1) = Cons(1,Cons(9,Cons(3,FNil())))
+def update(e: A, pos: Int): FList[A]
+</code>
+**6.3.** ''append'' concatenates this list to another:
+<code scala>
+def append(l: FList[A]): FList[A]
+</code>
+**6.4.** ''reverse'' returns the reversed list:
+<code scala>
+def reverse: FList[A]
+</code>
+**6.5.** ''last'' returns the last element of the list:
+<code scala>
+def last: A
+</code>
+**6.6.** ''filter'' filters the elements of the list:
+<code scala>
+def filter(p: A => Boolean): FList[A]
+</code>
+**6.7.** ''zip'' combines two lists into a list of pairs. If **either** list is larger, the remaining elements are discarded.
+<code scala>
+// Cons(1,(Cons(2,Cons(3,FNil()))).zip(Cons(true,Cons(false,Cons(true,FNil())))) =
+// Cons((1,true),Cons((2,false),Cons((3,true),FNil())))
+def zip[B](l: FList[B]): FList[(A,B)]
+</code>
+**6.8.** ''insSorted'' inserts an element into a sorted list so that the result is a sorted list.
+<code scala>
+def insSorted(f: A => Int)(e: A): FList[A]
+</code>
+**6.9.** ''sortBy'' sorts a list using insertion sort.
+<code scala>
+def sortBy(f: A => Int): FList[A]
+</code>
+**6.10 (!)** Implement a method ''pack'' which encodes a sorted list as follows:
+<code scala>
+[1,1,1,2,3,4,4,5,6].pack = [(1,3),(2,1),(3,1),(4,2),(5,1),(6,1)]
+def pack: FList[(A,Int)]
+</code>