Map
List.map
applies a provided function to all elements of a list.
Example
( List.map negate [1, 2, -3] ) == [-1, -2, 3]
( List.map abs [1, 2, -3] ) == [1, 2, 3]
Problems to solve using List.map
Problem 4 - Count the elements using map. Hint: after passing a simple function to map, you can get the count by calling List.sum
.
Problem 10 - Convert a list of lists to a list of lengths.
ConcatMap
List.concatMap
applies a function that returns a list to the elments of a list, then concatenates the resulting list of lists into a single list.
Problem 14 - Duplicate each element of a list.
Problem 15 - Repeat elements of a list.
Problem 7 - Flatten nested lists.
Problem 12 - Decode a run-length encoded list.
Problem 72 - Collect the nodes of a multiway tree into a list.