ImmutableList

Custom ImmutableList Java. This is a custom list in java which will take array list as a constructor and creates a immutable list out of it. Provides helper functions to retrieve the data

ImmutableList immutableList = new ImmutableList(arrayList);
//immutableList is arraylist of immutable object with a new reference 

head()

Returns the first element of a list.

tail()

Returns a new list with all elements of the original list except the first.

cons(Object obj)

Takes an argument and prepends it to the list.

drop(int n)

Takes an integer ‘n’ as argument and returns a new list after removing first n elements from the list.

reverse()

Returns the reverse of a list.

filter(predicate)

Takes a predicate(function, lambda or anonymous class) as an argument and returns a list only containing the elements which satisfy that predicate

Note:

Each one of the above operations  return a new list with the input list left intact. 

Useful links

https://en.wikipedia.org/wiki/Immutable_object