purescript-difflists [](https://travis-ci.org/Thimoteus/purescript-difflists)

A difference list supports fast appending on both sides. A difference list is just a function that takes a new list and appends it to the "contained" list. This means appending is reduced to function composition. This is useful if you're appending to the right side many times.

Note however, that transforming to a normal strictly linked list takes linear time. Therefore, you should only consider using a difference list if you can minimize the number of transformations: for example, only turn it into a normal list once when you're done appending.

Benchotron benchmarks

For comparison, here is a benchmark between lists and sequences.

Installation

bower install purescript-difflists