(take-while f coll)
The take-while function takes 2 arguments :
f: a function that takes one argument x and returns TRUE or FALSEcoll: a collection of items
take-while starts from the first item in the collection and returns the sequence of all successive elements for which f returns TRUE. As soon as f returns FALSE, take-while terminates and does not process any further elements.
Unlike the filter function, take-while doesn’t go through all the elements in the collection.
In the animation above, f returns TRUE when the element is green. The third element (blue circle) interrupts the iteration through the collection: the last element, although green, is not returned by
take-while.