Add more transformers for interaction with collections #37
Description
Transformers that should be added include:
- head
- last
- tail
- take
- takeRight
- takeWhile
- drop
- dropRight
- dropWhile
- partition
- contains
- containsSlice
- endsWith
- startsWith
- filter
- find
- map
-
flatMap - flatten
- fold
- foldLeft
- foldRight
- groupBy
- grouped
- indexOf
- indexOfSlice
- length
- join
- reduce
- reduceLeft
- reduceRight
- reverse
- slice
- sortBy
- splitAt
- sum
- zip
- unzip
- union
This list draws on the methods available to Seq descendants in Scala